On LED lighting

Ron's Technical Tips No. 2.3 Amps

LED's - an alternative view.

Based on my own experience, and on reading pretty much every post on here since the beginning, I am starting to feel slightly negative about LED lighting, or at least about about installing them everywhere.

There are two main reasons for this - the first is how they look and feel - the aesthetics of them, and the second is just how much power do they really save?

Don't get me wrong, I like my LED installation, but it has taken me several years and at least 3 separate designs to get it to my satisfaction, and my present installation is in addition to and not instead of the original Hymer lighting. 

The first mistake I made was thinking that all leds are the same. They are not. I had to learn about "colour temperature", and that there are many, many shades of white. Several years ago it was difficult to know what you were buying, but now the market has settled down into roughly 2 shades of white - "cool white" and "warm white". Most people know this nowadays, but it is worth saying for the sake of completeness. Cool white is very bright and has shades of blue, and warm white has more yellow. It's down to personal taste, but in general most comments I have read indicate that warm is the way to go in a van, and cool is too harsh, a bit like an operating theatre. The main thing to remember is that it can make a big difference, and getting it wrong is just a pain in the rear. My first bathroom install lasted less than 24 hours before I put the old bulbs back!

The second mistake I made was underestimating the quality and design of the original lighting. Having lived with it for many years, when I started to replace elements of it, I found that I really missed them! Not only the lighting, but the feel and temperature as well. This is the main reason why I have retained nearly all the original lights in my present installation. I think one of the reasons for this is that most of us grew up with the look and feel of the old style lighting - both incandescent and fluorescent. Am I the only one who so often goes into a pub or restaurant which has just had all it's bulbs replaced willy nilly with modern bulbs, and gone "ouch!"?

So what's the appeal? Power saving! You are all mostly shouting. Well I have looked into this quite deeply, and I just don't think the power saving is all that great, or that important. Most Classic Hymers have a combination of 12v strip lights, and small round halogen spots. The strip lights are quite efficient, about 1 amp, and the spots less so at about 2 amps. On paper the difference is quite big, but in reality? I can't imagine a situation where you would have all the lights on for 6 hours. So the lighting "bill" for an average evening might be in the order of 10 amps. Yes the led's might only consume 20% of that - but so what? You have at least a 100 amp battery - you can afford it! And the real deal changer in recent years is that fact that the vast majority of us now have solar panels or some sort, which start to work as soon as the sun comes up, putting power back in.

As an example - take the 4 bulb bathroom column in most Classics. Switch it on and watch the rest of the lights in the van dim, and watch the needle zoom into the red! But Hymer always did things for a reason. You need light to do your makeup (Jon Avery!). As soon as you do away with those 4 powerful bulbs, you will miss them! And the reality is that Hymer didn't bother about how much power they used because they would only be on for a short time. They might use 6 amps - but for how long? So think about this before you rip them out.

My contention is that it isn't how much power you save, but how you use the power available. 

Power saving through lighting is only really a big factor if you are spending a lot of time off grid, and in particular in winter, where there is less sun available.

I am not trying to put anybody off LED lighting, but I do think there is more to think about than just power saving.

Finally, here are some random thoughts about LEDs.

Led strips in the curtain pelmets look super! But you have to install them properly. Nearly all the self adhesive strips I have used have eventually started to come down after a year or so - it can be very frustrating. You have to clean the surface very well, and basically if it doesn't say 3M on the backing strip - don't use it! You can repair falling strips with hot melt glue, or other glues, but it's a fiddly job.

RBG strips that change colour are very funky, but not as replacement lighting. The white that they produce is not liveable with. I suggest RGB strips for decoration and entertainment only.

LED bulbs that consist of lots of leds in clusters are, only in my opinion, the most potentially disappointing of all. Just one faulty flashing led and the thing becomes a source of annoyance. There have been gazillions of cheap Chinese led bulbs on the market, and already I reckon most of them are in the bin. If you have to use bulbs, buy the best you can possibly afford.

Quality in general can be pretty bad. On the whole I have been disappointed with the quality of the components I have used over the last few years. Last year I decided to go in the opposite direction and seek out the most expensive gear I could find - the sort used by proper fitters in commercial establishments. So far a year has gone by without a single fault. So you get what you pay for. Bear in mind that you really only want to do the job once! 

If you are getting on a bit, and find that you need more light than you used to for close up work, then well installed, powerful, high quality, dimmable, warm white led strips can be an absolute boon - especially over the kitchen and dining area.

So in conclusion, think twice, plan your installation, use the highest quality you can, think carefully about the aesthetics and don't be obsessed with power saving.

Also

On the subject of the original Hymer tube lights - most of us have one in the bedroom and one in the van. These were (I think) made by Philips, and are no longer available. However they are a lovely design, and part of the Classic look. They don't consume a lot of power, and have a nice light. The tubes can be replaced, but when the transformer goes, as many do after 25 years, then it's quite a wrench to replace them with a modern unit. However it is a very worthwhile project to rip out the insides and install warm white led strips inside. The end result is very good, and preserves the "classic" feel.

More musings on buying vans (clipped from FB)

I've had 2 S700's in the last 15 years and I love them. Assuming you are not afraid of a toolbox and rolling your sleeves up, then this is my advice. You won't find a perfect van, so it's a matter of how much money and work you are willing to commit to any given van. Most things in a van are cosmetic and not worth getting worried about, as long as the price isn't daft. Batteries, appliances, fridges, wiring, front dash board etc are all reasonably straightforward DIY jobs, and there is usually plenty of work to be done, unless it's been kept on top of by a previous owner. So what you are really looking for is a van that just "feels right" - something that can be worked on - a vision. At a basic level it is a box on wheels, so it's the box and the wheels that need to be looked at most carefully. Look at the expensive things. You want an engine that sounds quite sweet and isn't leaking oil, although some oil leaks can be easily fixed. A bit of smoke from cold is fine and should fade away. Check an auto box very closely, it is imperative to have a test drive. The van should move smoothly through the gears, and kick down on hills. You want progressive acceleration up to 50-60 and then a reasonably smooth cruise - these vans are not fast. Manual boxes should select all gears normally, but don't worry about 1st gear being stiff and difficult to engage. It's a crawler gear and designed to be selected at standstill. If the stick feels spongy and sloppy then it's usually the selector mechanism, not the box itself, and easily fixed. I have written another article about this on this blog. Steering should be reasonably tight and vibration free, but problems here are usually just a matter of worn bushes and easily fixed.

Next, use your nose and smell for damp. Old Hymers are generally watertight unless they have been damaged or abused. 

Around the front end drivers door, if it has one, and the dash board - which is a favourite for getting rotten - it's a piece of plywood and gets soft from all the condensation that drips down the inside of the windscreen. It's a weekends work, and pretty much every old Hymer needs it done at some stage. A knowledgeable seller will tell you if it's been done, but if not, rock the van from side to side, inside, and if you see any movement between the bottom of the windscreen and the dash board, then you know it will need doing. It shouldn't be a deal beaker if you like the rest of the van and are handy with tools, a drill and a jigsaw.

Then take a good long look underneath - you are looking for any areas of bad rust on the main chassis members. Hymers were very well undersealed at the factory, so don't be suspicious if you find it surprisingly clean, but occasionally you will find chassis members flaking with rust, especially behind the back wheels. If the van has mudflaps at the back wheels, that's a good sign. Also check the rear of the floor right at the back in the boot - it gets rotten with all the road water.

Also - these vans have character. Just sit in it quietly for 5 minutes and imagine yourself living in it. Hopefully it will whisper to you!

Price wise - The Germans are asking around £16k for fully loaded lovingly maintained examples. For this sort of money it should be perfect. More than perfect! Most UK vans that need a bit of TLC are around £10 to 13k. Maybe a bit more at this time of year. The right price should be the purchase price plus whatever you need to spend to get it up to scratch, so if you have a fixed budget bear this in mind. If you find any areas of concern and need advice, take pictures and an audio recording of the engine and come back on here. Good luck! 

Why is it often difficult or even impossible to select 1st gear on the Mercedes box?

RONS'S TECHNICAL TIPS No 5 speed box

I have just been asked (again) why is the pre 95 Mercedes gearbox so difficult to get into 1st gear. Fiat owners will take comfort that just as they have an occasional problem with 5th, the Merc 1st gear is also an awkward child.

This is a long read, so if you have no interest in the intricacies of a Mercedes gearbox then get on with your life now!

QUESTION - Ron I am finding 1st a little tough sometimes. Not crunchy just seems a tighter gate than the rest. It's getting better as I get used to it. It doesn't jump out or anything. I have also found a "false gear" to the left of 1st. Is this something you have fixed or got used to? Cheers, Julian.

ANSWER - 

Yes it is exactly as you describe. First is stiff and awkward, but not temperamental - you can master it. The reason it is stiff is that it is a very low gear and spinning very fast even in relation to the engine speed at tickover, so the synchromesh rings have a lot of work to do to spin the gear up to speed before it can be engaged, and so are manufactured bigger and tougher on 1st gear for this reason, and so need more pressure to engage. It shouldn't be a problem because 1st is a crawler gear and usually always engaged when stopped. You just have to maintain pressure on the stick a moment longer to allow the gear to spin up, and then it should engage smoothly. The false gear you refer to is no mans land between 1st and reverse. !st is slightly to the left and back, reverse is fully to the left and forward. The stick naturally rests between 2nd and 3rd. If you push the stick towards the left you will feel 2 resistances, the first is where you pull back to 1st, and the second, further over, is a full stop, and will only go forward into rev. The trick is to know these two positions, and not to make the mistake most people make, which is to ram the stick all the way to the left and then pull back expecting 1st. This reason and this reason alone is why people accuse the Mercedes box of being a bitch. This is a bit unfair as it is actually a bullet proof box, it just has "character"! The most you can criticise it is that it is old fashioned compared with modern boxes, which are silky smooth, and have well defined gates (the layout of the gears). 

However on a very steep hill, you may find yourself wanting to do a moving change down from second to first - it is a rare situation, so doesn't get much practice. Basically, as others will testify, it is an almost impossible change. It has to be done quickly, or the van will stop, so it get's rushed and fluffed. As I said before, if 1st gear is spinning fast on tickover, then with the engine revving highly climbing a hill in 2nd then it is spinning even faster, too fast even for the synchromesh rings to have any chance of spinning the gears up to a speed where they match each other and can engage smoothly. So it refuses to go into first and the van stops on the steep hill and you have to engage the handbrake quickly, then select 1st and smoke the clutch to pull away again, and then remain in 1st and crawl up the hill at 10mph as you are afraid to change gear!

The answer to this is to master the ancient and lost art of double declutching. Baby boomers (and their parents) should remember the days before synchromesh when all boxes were "crash" boxes. But before I describe double declutching, I have to describe what synchromesh is. Most people know that a gearbox has cogs inside of different sizes to allow the same speed of engine revs to deliver a range of different road speeds. But when you want to change gear, the cog that is connected to the engine, is spinning much faster (or slower) than the next cog of the gear you want. If you try to push two cogs together that are spinning at different speeds, then of course you get that familiar grinding sound. The only way to get a smooth change is to match the speeds of the two cogs before pushing them (engaging) together. This used to be a matter of pure skill. Drivers had to be intimately aware of the speed and sound of every gear in relation to road speed and to skilfully use the accelerator (and the clutch) to match the speed of the engine cog to the speed of the next gear cog. They did this by either letting the engine revs fall, changing up (easy) or increasing the engine speed, changing down (hard). The trick was to gently let the gears just touch each other with hand pressure on the stick and feel the vibrations of the gears and as soon as they matched up, push in the gear smoothly - pure skill! After WW2 and through the 1950's as cars became common for non professional drivers, Porsche and others eventually came up with a much better system, known as "synchronised shifting" or synchromesh. This is an extra mechanism in the gearbox that does mechanically what the driver used to do by skill - it matches up the gears perfectly before engaging them, using an interlocking system of spinning rings and cones. When you change gear in a synchro box, the slight resistance you feel as you enter a gear, especially on older cars, is the synchro doing it's job. Nowadays it's all computer controlled, but not on Classic Merc Hymers!

It should also be said here that the selector mechanism - the system of rods and joints that connects the bottom of the gearstick to the selector arms on the side of the gear box - is also an important part of this setup, and should be kept well lubricated and maintained - 90% of the time when people think they have a bad box - it's just an easy fix to the selectors. If your gear change is very stiff, or sloppy like a bag of spanners, then your selectors need sorting out - an easy job.

So, back to double declutching! Synchro can only achieve so much, usually the differences in speeds between gears are not so much, so changes are easy and smooth. But in the case we are discussing - down in 2nd and 1st where the engine is revving highly, the speed difference is too much to allow the change in the time needed, hence the resistance, and difficulty in getting into 1st. To get round this and effect a smooth change - yes it is possible - you have to use a trick from the old pre synchro days, known as double declutching. You depress the clutch, pull the stick back from 2nd into neutral, and just hold the stick with gentle backward pressure right at the point where it should go into 1st, then lift the clutch, blip the accelerator, which revs up the engine, and then depress the clutch again and slip into 1st when you feel the resistance drop - all in one easy fluid motion that takes only slightly longer than a normal change down. This has the effect of spinning up 1st gear and making the change much easier. In fact it is basically the only way to make a moving change into 1st gear on the Mercedes box (pre 95). And this is the main reason, if not the only reason, the box has a bad reputation, because all the other gears are pretty much silky smooth. 3rd to 2nd is occasionally similar, especially when flogging up a hill, and this change can also be made smoother by ddc'ing.

It is a difficult manoeuvre to perfect, but not impossible, it is similar to a dance move - coordination of hands and feet movement. This is why you often hear trucks (in the old days) making that familiar sound as they came to a hill - the engine revs fall, then he changes gear with that familar blip of the accelerator, and then the engine revs resume at a higher note. Almost impossible to describe in words, but instantly recognisable if you hear it (and are old enough).

It is a vey satisfying technique to master, and it is essential if, like me, you want to really push your Hymer up the steepest of hills and hairpins, like Hardknott pass in the Lake District, and the even more spectacular minor Alpine passes. A fully loaded S700 or S660 just doesn't have the guts to get up a 1 in 3 in 2nd gear, especially if there is a hairpin coming, so you have to be able to get into 1st quickly and smoothly and with the minimum of loss of speed. The only other alternative is to know the road and what's coming, and select first from the bottom, and grind up in 1st without changing gear. Also there is no shame in having to stop to engage first on a steep hill - you have a right to be there so the guy behind in his Audio Quattro paddle shift computer controlled 6 speed auto box in sport mode can basically sod off!

Fridge problems?

Ron's Technical Tips number -10 degrees

FRIDGE PROBLEMS

It's the time of year when our vans come out of storage and many of us have fridge problems.

What most of us have to remember is that our fridges are quite often original, and that makes them over 20 years old. Not many home appliances last that long, so it's not surprising that we get a lot of fridge problems.

Here in very simple terms is how your fridge works. At the back there is a chimney. At the bottom of the chimney is a gas burner, heat from the flame goes up the chimney and passes into the tubes that contain a chemical, which converts the heat into cold - very simple explanation.

Also in the chimney are two heating elements - one powered by 240v and the other by 12v. So there are 3 possible sources of heat to heat up the chemicals.

The commonest problems are the fridge not working on any of these 3 sources, so we will discuss each one in turn.

Gas. The commonest fault is that soot and or crap falls down the chimney and onto the burner which either restricts the flame, or preventing it lighting at all. This is quite easy to fix, as long as you can get access to the burner assembly, usually but not always through the lower ventilation panel outside.

The next problem with gas is that it won't light. It acts just like a cigarette lighter - you press the button, the gas is switched on, and a spark ignites the gas. However unlike a cigarette lighter, when you take your finger off the button, the gas should stay ignited. This is because there is a safety feature called a thermocouple. This is a little finger of metal that is placed in the flame, and if it gets hot, as it should, then it operates a gas valve that keeps the gas flowing. If the gas goes out, it cools, and shuts off the gas. If the gas lights, but goes out when you take your finger off the button after about 20 seconds, then it is usually the thermocouple. The thermocouple is a fundamental safety feature.

The next problem is no spark. When you try and ignite the fridge there is usually a tick tick sound which is the spark. There is another little finger of metal placed in the burner that allows the spark to jump between it and the burner body, again just like an electronic cig lighter. If there is no power getting to this, or the spark can't jump because of crap and soot in the burner, then it won't light.

Finally - there just might not be any gas at all! After storage with the gas turned off, there may be no gas in the pipes, or it might take a while to come through. You have to be patient. Sometimes it's a good idea to light the cooker to promote the gas flow through the pipes, and do remember to make sure all the relevant gas valves are open.

Electricity. Both 12v and 240v elements work on the same principle - just like a kettle element. Power is applied and the element gets hot. Other than making sure the fuses are OK, there is very little to go wrong and if it doesn't work then usually the element has given up the ghost and needs replacing. Occasionally you get a faulty switch, which can be hard to troubleshoot without access to the back of the switch and the use of a multimeter.

Don't forget that in a correctly wired van, the fridge will only work on 12v when the engine is running. If everything else works fine, but you are not getting cooling while driving, assuming it is actually switched on to 12v, the the commonest reason is that the relay which switches 12v from the engine alternator to your fridge is broken. This relay is usually to be found behind the main habitation fuse panel. You should also remember that the 12v element is the weakest of all the heat sources, so the fridge will be less cool when driving than it will be on gas or 240v.

If the fridge is working but not getting cold, or just getting cold at the top, near the freezer box, then this usually means the chemicals have got separated in the pipes. There are various techniques to try and fix this and Peter Curry is our resident expert. 

There are plenty of how to fix videos on Youtube and lots of previous posts on this group, if you are a DIYer, and we have resident experts and recommended engineers to help you out if you are not.

Don't mess with gas unless you know exactly what you are doing - it is quite an easy job to clean rubbish away from the burner, but anything that involves undoing actual gas fittings or pipes should be done by a trained gas man. Replacing elements is also quite a tricky job.

Finally - we all like to keep our vans original, but fridge problems are one of the commonest problems we find on the group. A temperamental fridge can ruin an otherwise perfect summer trip. Nothing lasts forever, so sometimes it's just best to chuck in the towel and buy a new fridge. The new Dometics are a lot better than their grandfathers, colder and more efficient. I gave in and bought a new fridge last year and we love it. But they ain't cheap! But don't give in unless you have had a proper opinion from an expert.

Stay cool people!

UPDATE - more information about the absorption mechanism by Peter Curry

Never turn your fridge upside down it will just pour all the sludge from the resevoir into your evaporation jet. what people are trying to do when they do this is to remix the chemical cocktail that is the driving force that makes your fridge cold.

There are much easier methods to try first , with fridge removal being a final option ready for rotating the fridge to mix the cocktail.
And even this is done in a prescribed manner and direction.
PLEASE DO NOT REMOVE YOUR FRIDGE AND STAND IT ON ITS HEAD you are taking a chance with the odds being about 35% for you and 65% against you.

If fridge has been stood for a while and will not get cold after being on on gas for 24hrs with good flame and flue then there are two possibilities.

1 the fridge is no good buy a new one
2 the chemical cocktail that runs the fridge has sperated out

These are chemicals that once mixed live reasonably happily in a cocktail but once seperated need some encouregment to join to gether again.
Put fridge on gas and if not single energy selector type, put the mains on as well and turn both to full, leave for 4 to 6 hours then turn fridge to 12v and take the van for a drive down a rough road - you are looking for vibration not bloody great potholes! About 1/2 hour is enough,
Then go home put fridge on gas and leave over night.
We have a 90% success rate with this.

Headlight adjuster conversion

RON'S TECHNICAL TIPS number 3.14 pi ...

If you want to get your Mercedes (and others) headlight adjuster working again, here is the kit to do it. Bookmark it!

http://www.ebay.de/itm/Elekt-Leuchtweitenregulierung-T1-T2-Bremer-Duessel-Mercedes-410D-208D-Hymer-S-LWR-/201545448425

And here is the amusingly machine translated description - I believe that "electricity thieves" refers to Scotchlok connectors, the use of which is a criminal offence in Germany...(well it should be!)

Electrical LWR Conversion Kit Mercedes T1 T2 Bremer

MB 208 MB 308 MB 410 MB 309 MB 310 MB 313

Hymer S Class S 550 S 700

Conversion kit from hydraulic to electric headlamp leveling.

As simple as NEVER !!!!!!!!!

Connect Only together Insert, and Plus & mass.

And all through the pre-assembled wiring harness.

Now with the use of the original knob

which keeps the optics in your vehicle 100% guaranteed.

We do not use electricity thieves !!!

Plus is taken in the fuse box of the low beam control, minus the star distributor under the dashboard

The leveling control is suitable for:

Mercedes T1 Bremer

Mercedes T2 Düsseldorf

MB 208

MB 308

MB 410

MB 309

MB 310

MB 313

Hymer S Class

Hymer Eriba S 550

Hymer Eriba S 700

For questions we are at your disposal.

Tel 06198-502296 e-mail:. Info@leuchtweiten-shop.de

  

 

This makes future heist in the main test,

HU Passed!

   

Here you can see the delivery ______________ use simply glue in the knob

The servo motors are a Swiss brand, have an aluminum shaft for receiving the ball head screws, are waterproof and have to adjust a manual adjustment knob at the back of the headlight basic setting.

Fittingly use for the Ducato 230, 280, 290, Volvo 440/460, Hymer, Mercedes all models with hydraulic leveling control, Fiat all models with hydraulic LWR

Delivery:

2 x headlight range control motor ( new parts ) Modified on a CNC machine for different vehicle types.

1 x Round regulator ( new parts )

1 x use for the conversion original knob.

3 x distribution for cable brown, yellow, brown / yellow (original equipment quality)

2 x cable ties with mounting base adhesive.

3 x cable ties

4-sided color and of course PRINTED installation instructions with pictures and diagram what good is a PDF in the workshop or garage.

Installation is carried out in about 2-3 hrs. For the Artisan somewhat gifted. (Are they talking about us Peter Curry​?!!)

We differ from others:

Because greed is not always Geil!

1. use the glue in the original knob!

2. servomotors are not open to cable to solder because Daduchus

leaks can occur.

3. It works with no electricity thieves because this cable be damaged!

4. Cable with three different colors 1mm Automotive OEM quality.

5. 2 x insulated terminals for + and ground terminal (see photo).

6. Cable ties and base adhesive.

7. Printed color installation instructions and no PDF I somehow self print needs.

Shipping: We only ship insured!

Shipping with DHL Paket in Germany for free.

For shipment delivery DHL +6.90 Euro

Delivery to the following countries: 14,90 Euro with DHL

Belgium, Denmark, Estonia, Finland, France (except Guadeloupe, Martinique, French Guiana, Réunion), Great Britain (except Channel Islands of Jersey and Guernsey), Ireland, Italy (except San Marino, Livigno, Vatican City), Latvia, Lithuania, Luxembourg Monaco, Netherlands, Austria, Poland, Portugal (except Azores and Madeira), Sweden, Slovakia, Slovenia, Spain (except Ceuta, Lanzarote, Fuerteventura, Gran Canaria, Tenerife, La Gomera, La Palma, El Hierro, Melilla), Czech Republic , Hungary.

Glowplugs - again - Overview ...

Glowplug problems can manifest in all sorts of spooky ways, but the system is quite straightforward and there are only two and a half points of failure. 1. The glowplugs themselves, or their controlling relay box. The half reason is the wiring - ie a wire gets rubbed or worn or damaged - very rare.
A glowplug is nothing more than a miniature kettle element, electricity is supplied to the plug, the element glows red hot, which heats the cylinder which helps the engine start when cold. Just like an electric kettle, after 20 years of use they can get a bit temperamental.
When you switch on the ignition, the control relay switches power to the plugs for a pre-determined amount of time, and lights the light on the dash.
All very simple and straightforward, until things get worn out!
Inside the box are relays, and relays don't last forever.
There is also a simple non computerised sensing circuit that does its best to tell you when there is a problem, but it's only output is the light, so it's a bit limited in the information it can tell you. There is no hard and fast way to tell what the problem is, except that whenever the light comes on when it shouldn't, or doesn't go out when it should, then there's a problem.
The good news is that the system is very robust - you won't automatically break down if you have the light on. The worst case scenario is that the engine won't start on a cold morning, and only then if all the plugs are not getting any juice.
The fix is easy - replace the plugs. A garage mechanic can check each plug with a meter and identify the faulty plug, but what's the point of replacing one - it is only the first one to go. Unless you have documented proof or memory to the contrary, then your plugs in a 20+ year old van are likely to be original. So replace the lot.
If you still have a problem then you have to replace the relay. Mercedes will try and charge you a fortune, but they are about £60 on Ebay, and you can DIY.
You can't blame either the relay box or the plugs for not lasting more than 20 years, so replacement will give you peace of mind for another 20.
But like I said - you can last for months or even years with the light coming on and off....but eventually, usually on a cold morning, you will be stuck.

Can't select first gear - possible gear linkage problem - also applies to any gear.

From Facebook

Hi, can anyone help. I have a S700 on a Mercedes chassis and have a problem getting 1st gear, the previous owner said he had changed a linkage on the gearbox and since then had trouble getting 1st gear all other gears are ok.

OK this should be pretty easy to fix. The crucial information is that you said "ever since" the previous owner had changed a linkage. In my book, that means he fitted it wrongly. The "left and back" first gear on the Merc box has always been a challenge for most, but it should work perfectly with practice - it isn't faulty by design. If you look at the side of the gear box you will see there are several arms about 6 inches long coming out of the side of the box, attached to rods running forward. If you get somebody to go through the gears (engine not running) while you look, you will see how the mechanism works, and you will see by a process of deduction which arm is responsible for selecting first gear.
The arms are attached to the little shafts that stick out of the box. Those shafts are splined - they have little grooves in them, and the round holes in the arms are similarly grooved where they locate onto the shaft. There is a bolt that attaches the arm to the shaft. It is my theory that the arm has been reattached to the shaft just a single groove (or tooth if you like) either way, incorrectly. So you should loosen the bolt and gently work the arm off the shaft, then relocate it one tooth to the left or right - I can't tell you from memory which way, you will have to do it by trial and error, but it will probably be in the direction which results in the arm traveling further, and thus engaging the gear more fully.
Having moved it one groove, either clockwise or anticlockwise, retighten it, and then jump into the van. Start the engine and depress the clutch, and then select first. You should notice straight away if you have got it right - first should select with a satisfying feel, no grinding of gears, and as you lift the clutch you should feel the power go to the wheels, without it jumping out of gear. If not, repeat the process one groove in the opposite direction. It is unlikely but not impossible, that you may even have to go two grooves - depending on how inaccurately it was originally fitted - but the fact that you say it is a problem selecting first gear, and not that you can't select it at all, indicates that it should only be one groove.
Of course I can't guarantee this fix, but from what you have said, and based on my own experience, it is certainly the favourite thing to try first. It is highly unlikely to be an internal problem in the box.
Somebody else mentioned bushes and it is also correct that the plastic bushes on the linkages can get worn, resulting in a similar problem, but on the basis of how you have described the problem, you should try this first.
If you are not mechanically minded, and in possession of a tool box, or at least a spanner, then just pop into your local or favourite garage and explain the problem, plus my comments, and they should be able to do all this in about 15 minutes.

Like · Reply · 1 · 3 hrs · Edited

Ron Bentham This is a picture of a 410D box,  You can see where the arms attach to the box - the opposite end from where the rods are attached. You can see that moving the arm one groove to the left or right on the little shaft will have quite a big effect - it only has to be one groove out to cause trouble.

Further thoughts. It pays for Merc owners to be familiar with the gear linkage mechanism. Many a holiday has been ruined when after a long trip, especially on rough roads, suddenly you can't get a gear, or any gear, and the stick feels like a bag of spanners. The obvious reaction is that the gearbox is knackered and that this is going to be catastrophically expensive, especially if you are abroad. In fact total gearbox failure is extremely rare, and the Merc gearboxes are as good as the engines - I have run them for 400,000km with nothing more than oil changes.

It is the linkages that cause the problems, as I have found out several times over the years. If the gear change is getting stiff, and giving the impression that it just isn't like it used to be, then it is usually just in need of a good clean. It is quite a complex mechanism that converts the movement of the stick into pushing and pulling the lever arms on the side of the gear box. If you look at the pic above, you will see that there is an assembly on top of the box that has the base of the stick sticking up out of it. This assembly contains a lot of levers and linkages that over many years can get very dry and dusty. There is a plastic cover about 3 inches by 2, which when removed exposes the mechanism - photos are hard to come by - it is not shown in the pic above, but if you get under there and have a good look, you will find it. The cover just pops off. Inside of there needs a good clean out and lube. You will be amazed at the difference.

The next problem is the dreaded "knackered box" scare. What has usually happened is that one of the selector arms, as in the photos, has simply worked loose and either started to slip, or even fallen off all together. If you are lucky you will find it still hanging around - if you are unlucky it will be gone, and it's a garage job, but won't be expensive. The problem is that if just one works off or loose, it is likely that the whole mechanism gets out of kilter and you can't select any gear. This happened to me in Italy once and the only gear I could get was third, but it was enough to limp off the autostrada, save myself a hefty fee, and limp to a local garage where they fixed it in 30 mins for 20 euros cash. I could have fixed it myself but it was raining and my back was killing me!

The selector arms attach with a single bolt - as detailed above, and they do have a tendency to work loose over the years. The problem when they come loose is getting them back on in the right position. I am sure there is a Merc workshop manual procedure for this, but out on the road you just have to do it by trial and error. Any decent rescue mechanic should be able to get you going again, especially if he is over 50! 

Finally, another lesser known problem is that where the actual gear stick fits onto that stubby stick on top of the box, there is a rubber sleeve fitted to dampen the feel. This can also get very worn after 20 years, and can also create the impression that the box is sloppy and  "on the way out" - a new sleeve for a few quid (if you can get one!) and the box feels like new again.

So be familiar with your gear selection mechanism and avoid that sinking feeling if it ever happens to you. It is usually always an easy fix, and of course regular maintenance is also important.