Diagnosing a holey 02S gearbox, any ideas?

I have acquired this rather lovely 02S box from a TDI Touran with the intention of adding a wavetrac and putting a late 02J bell housing on it which i've got lying about. The only issue is it seems to have popped the end cap of the main shaft bearing and I would rather like to avoid this happening to my new bell housing lol.

Details are that it was from a touran that had an all round smash that wiped out all the outer panels hence it being written off. It was driven to the yard and the car was broken to find this:




They even provisionally sold it and had to give the money back when the crack was found! Everything turns, all gears engage smooth as silk, gear oil is mostly all over the case but what is left isnt black and doesnt smell burnt.

I'm having a hard time finding anything similar anywhere on the web so either VW are very good at hiding it or its quite rare. Current theory is either during the crash somehow? or diff snatch when a wheel gained traction and the force went into the shaft and pop, though the EPS should stop that... both seem unlikely.

Will be splitting it next week so maybe have a better idea then but does anybody have any ideas/theories/examples in the mean time?

Cheers

 

No pics up just blanks at the mo.

 

no pics to look at, but they are good boxes, but hard to find, i have one in the race polo, recently rebuilt by Hotgolf lol

 

Use Picasa (sp?), much more reliable than PB..

 

Thats the pics fixed...

Yeah, managed to get it for a bargain due to the hole so was too good to miss. Spoke to my local VW yesterday and got the response I thought id get, "never seen that happen before". hmmmm

 

I bet it's had a bang on the other end, or if its been apart they hammered the bearing in hard .
The thing is with most dealers these days is if there's a big box problem they just fit a new item, especially if its under warranty. Half the vw techs wouldn't even attempt stripping or diagnosing a gearbox.

 

Yeah, I would agree about the techs these days. Everybody I've known to have had transmission issues has had it replaced and sent back to where it came from (mostly Italy haha).

This one might have had a bang during the crash (though there are no marks?) and it makes me feel better that somebody else thinks it might have been that. I'm not going to be asking too much from it in the near future but a big turbo might be on the cards next year .

 

right, a wee update on this as ive been a bit busy of late. I got cold feet and decided to give the job to a friendly gearbox builder who now has the box as of friday. he was also very surprised at the damage but was very complimentary about the rest of the box (feel, gear change etc). im goin to get the day off work and join him on thursday to watch/learn and take pictures so if anybody wants anything specific, just shout. otherwise ill snap away at everything as iv not seen many guides on the 02S anywhere.

 

Its basically thesame as the 02a thats why lol. Only the 5/6th end is different and it's not difficult at all if you can build a box. Just make sure the new box is pre-loaded properly. I've had countless boxes and discruntled owners turn up with a box with shafts 'floating' about due to p155 poor assembly from 'Pro' mechanics!

 

you dont know how right you are mart! the plot thickens with this one as it was missing the two end bolts that hold 5 and 6th to their shafts! rest of the box looks good though so its hard to understand why somebody would remove them and continue to use it till it broke! ill make sure this guy puts them back in lol .

i probably would have had a go at pulling it apart but without any pics online, thats what sorta put me off. ill post what i have when i get some for future reference.

 

with box in bits the picture became clearer, its the old rivet head shearing off problem that caused two teeth to fall off the ring gear. very luckily that was the only damage done but now i have find a new ring...

sooo, if anybody has one please get in touch . got an ad in the wanted section too. ratio is 3.65.

lastly, what kind of issues could i expect from using miss-matched shaft and ring? more noise nd more bits of metal in the box im guessing but an oil change and careful driving for a while should help right?

 

Good to hear you found the cause, I was also going to say I've never seen a 02A based box fail like that!! I'll agree Techs don't strip boxes, well it is a very specialised skill when you have to use basic maths to work out pre-loads !!

if your looking at an exact ratio ring gear, there shouldn't be any issues, a different one would require deeper research- but also changing the box housing / casing the pre-load will need checking/adjusting again

 

In theory there is no mis-match as the items are not machined as a pair, although yes, they have worn in as a pair and you may end up with unwanted back lash or extra gear noise. Use a thicker oil and see how it goes.
Make sure you have the right crown wheel though or you'll have some expensive scrap lol I'll have a look when I get home for one.
Double check the pinion shaft for damage, this is the expensive bit

 

thanks guys, the advice is much appreciated as always.

ive been staring at google for days now to no avail in finding the new ring gear. vw want 409 for a complete dif and ring (0AH 409 021 N) and ONLY 219 for the shaft (02S 311 205 K). they dont even have a part number for the ring on its own so hunting for one online is harder. the reg i've been using is SM54YUE, just in case anybody has a better method of searching.

next weekend is d-day so i'll have to go 5 speed again if i cant find on soon... meh

 

What's the tooth count on the one you have there?

 

its a 62/17, GQN box.

 

Still in Crete so I'll have a look Friday.
If not though, get on Etka/vagcat and look to see what others use that ratio and tooth count and pick up a 2nd hand box. Far cheaper than a new one!

 

Thanks mart and mr rub. i obviously couldnt read my VW man's writing as it definitely is the latter 62/17 type lol.

My biggest problem has been identifying boxes that I could break that have the later style bolt pattern on the ring gear as I've already bought the later style wavetrac to fit it. I'll run upto vw now and get a complete list of vehicles and hit fleebay tonight.

If I cant get it sorted this week it'll be going into the EBJ that i've also got in bits though I hope it doesnt come to that...