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luke2152

New Member
Joined
Mar 19, 2017
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24
Car
vito 111
Apologies but I'm too new to use the private messages.
I have a vito with what I think are moderately worn 1st and 2nd synchros and a reverse that occasionally pops out of gear. Not a bit deal for now. But I've picked up a used gearbox with a first gear fault so I can rebuild it at my leisure and swap them over. Read your thread on replacing the selector (I'm actually thinking of welding a bit of bronze in place of the plastic shoes) so I was hoping you'd have some more photos of stripping it down or ideally an exploded diagram so I can figure out how to strip it without destroying it!

Any relevant info from others graciously accepted too
 
Hi there Luke2152.
Sorry for the delay in responding, I've been very busy just lately. I'm also too shattered just now to post a decent reply.
I'll have a sleep,, ad look into this later today.
 
Apologies but I'm too new to use the private messages.
I have a vito with what I think are moderately worn 1st and 2nd synchros and a reverse that occasionally pops out of gear. Not a bit deal for now. But I've picked up a used gearbox with a first gear fault so I can rebuild it at my leisure and swap them over. Read your thread on replacing the selector (I'm actually thinking of welding a bit of bronze in place of the plastic shoes) so I was hoping you'd have some more photos of stripping it down or ideally an exploded diagram so I can figure out how to strip it without destroying it!

Any relevant info from others graciously accepted too
Ok, before you drop out your existing gearbox what sort of miles has it covered please.?
The reason I ask is because the "Worn Synchro" effect is apparently often remedied by simply changing the original gearbox oil for ATF (no, I am not kidding). Details at.: Poor First Gear Selection - Manual Gearbox Problem W639 Vito - Cure
The Reverse selection issue seems to usually be down to the adjustment of the cables (which is done at the gear lever selector mechanism, in the cab)

That aside, I found the gearbox is fairly straightforward to strip. I have a copy of WIS & used that together with some sweat & tears to strip & rebuild mine. I took quite a number of pictures as I went, and will happily share any that you feel may be useful.? :)

However those bushes that had worn on mine are unlikely to be successfully replaced by welding a piece of bronze in their place IMO. -Perhaps if you have someone who could engineer some bronze ones to the exact shape of the originals, but then you would still have to figure out how to effectively secure them.
 
Milage is 150k and i did change fluid to ATF. The old oil came out looking like quicksilver with a few large metal bits so I'm honestly surprised it still runs fairly well.

For the other gearbox i brought i got the output flange off its spline and undid the ring of bolts round its circumference. Can pry the two casings apart a just couple of mm but don't want to force them because i dont know whats holding them. Just the bearings? Or something else. Do i need more force, heat, a puller, a hammer etc. Do i need to remove the external bits of the shift linkages before i pull cases apart.
 
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.For the other gearbox i brought i got the output flange off its spline and undid the ring of bolts round its circumference.
There is also a bolt inside the bell housing, behind the blind seal (which you will need to buy a replacement for when you rebuild the gearbox)
This is bolted into the end of the countershaft, so DO NOT try to split the two halves before having released that bolt.!!
Removing that cover plug without damaging the housing it seats in will result in it's destruction, but take care when removing it not to damage the casing itself.

Yes you should remove all the external selector mechanisms before stripping the box.
Do i need more force, heat, a puller, a hammer etc. Do i need to remove the external bits of the shift linkages before i pull cases apart.
I used a combination of three legged pullers, wooden mallet, various drifts & a lot of care & patience.
 
Thanks for the tips. Should have guessed they'd hide a fastener behind the seal. I'm away for couple of weeks but will crack on with it after. Has anyone seen a single mass flywheel kit for w639? Theres loads out there for the w638
 
Thanks for the tips. Should have guessed they'd hide a fastener behind the seal. I'm away for couple of weeks but will crack on with it after. Has anyone seen a single mass flywheel kit for w639? Theres loads out there for the w638
I'm sure I've seen them advertised. However having done some reading up on the subject I have decided that I will be staying with the dual mass arrangement that the Mercedes designers chose to employ if I ever need to replace mine (still seems fine, at just 240k miles)
 
Got box pulled apart today (the spare one that is - not the one in my van). The little teeth that engage the 1st gear and are a part of the gear (I don't know the technical name) are badly worn which isn't surprising as the guy that sold it to me said it kept popping out of first. The plastic sliders in the selector forks look ok except one appears to be missing (not on the end of the forks but in the middle it looks like there should be a slider but there is none there although I think it wont matter much with the other 2 sliders in contact).

So I guess I'll be needing a new 1st gear and a set of bearings and seals and touch wood I can remember how to put it all back together!
 
Got box pulled apart today (the spare one that is - not the one in my van). The little teeth that engage the 1st gear and are a part of the gear (I don't know the technical name) are badly worn which isn't surprising as the guy that sold it to me said it kept popping out of first. The plastic sliders in the selector forks look ok except one appears to be missing (not on the end of the forks but in the middle it looks like there should be a slider but there is none there although I think it wont matter much with the other 2 sliders in contact).

So I guess I'll be needing a new 1st gear and a set of bearings and seals and touch wood I can remember how to put it all back together!

Fwiw I brought a new 1st gear for mine, thinking that it would be the cause of the issue. (even though mine looked pretty much perfect ).
Part number was MA203 260 28 08 & it cost about £ 50
However when I rebuilt the box with that new gear & bearings etc..., it still had exactly the same issue.
It wasn't until I replaced the selector cage, with it's new sliders, that it stopped popping out of first gear.
I "only" removed, stripped, rebuilt & refitted my gearbox four times before I got it right.
Good job those blind covers in the bell housing are only a couple of quid each, 'cos I kept having to buy a new one each time.! :wallbash:

:) Good luck, & let me know how you get on please mate.
 
I've been lazy with this mainly because the gearbox in the van is not getting worse - and also because my bike is more fun to tinker with. But got back to work on the vito 'box and when I went to order parts I realised the spare one I have on the bench is from a 109 vito (gearbox 716.637) and my van is 111 vito (gearbox 716.652). I'm not sure if they are interchangeable although they look very much the same. The 1st gear is a different part number for each so there must be internal differences at least - maybe different gear ratios.
 

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