Gearbox guru advice needed

[SteveH]

I have a problem with a 5-speed S2 box which I'd like to understand before committing to having it rebuilt. Hopefully someone who's opened up an Audi box might be able to point me in the right direction. I don't think I'd have the tools to split a gearbox, so I'm not planning on doing it myself.

Symptom: Grating sound under load in first and second, progressively quieter as you go up the gears. I thought it might be galling on the faces of the gears, however having had a look at the box today I think it's something else.

I have noticed that the input shaft has back to front movement (guesstimate a few mm) When pushed back in towards the box and rotated it makes a nasty grating sound. When pulled forwards and rotated it's smooth and silent. Having checked a spare box, I see there is zero front to back play, so the culprit must be linked to the main input shaft, gears on this shaft or bearings. Does anyone know whether there is an obvious bearing/thrust washer which might have gone south? The box was rebuilt two years ago and was running fine until this started. I have dropped the oil and there are very fine silver particles, nothing more than a sheen on the surface of the oil. Nothing like the material I'd have expected if a bearing had let go......ideas?

[Cottis]

My 3b box started making "noises" a while back. A cross between whining and chattering rather than the grating you are talking about.

Anyway, I had it reconditioned and when the guy took it out initially to listen to the problem, he claimed his junior could not hear it. I insisted he took it out himself and he then came back to me to say he could hear it although he did not think it was that bad. Turned out the pinion bearing was completely jiggered. He was amazed that 1. It had not let go and 2. That it was making such a quiet noise given how bad it was. He said it was a good job it did not let go or else it would have taken out a lot of the internals. As it was, a new bearing (about £150 from memory) some machining and much labour saw it put right. It was lovely once completed

Stupidly I then sold the car. I recall him saying the main gearings can not be purchased separately, so you wanna pray it is a bearing and not the gears (it was over £1500 for the full set) I think it was Alex who told me that the pinion bearing is the weak spot in the 5 speed boxes. It might be that.

[pixsaudisex2]

Would be a bearing as a few will say Central axles are a good company and charge just for the problem no extras..

[diesel des]

In a 6 speed 01e a bearing near the back of box limits the movement you describe. Shouldn't be too hard to change.

[diesel des]

A bolt tightness to pull the shaft into the tapper. It could of came loose? Remove the center diff and yiu will see it behind the oil seperator thing.

[SteveH]

Thanks for the advice. I think I may as well pull it apart and see if there's anything obvious. It would be good to get it fixed as it's perfect apart from whatever has worn/come loose.

[diesel des]

So I went out and took some pictures. Take the rear housing off were the prop shaft bolts on. It's just a few t45 bolts. The housing will come off with the shaft coupling. It's spring loaded so catch the spring and washer and shim. Then just pull the torsen diff out by hand.

Then you will see the oil seperator thing. It's brown plastic. Pop it out with a screw driver.



Then you will see a splined bolt behind it. It holds the input shaft tight to a bearing race.



That bearing part runs on a ball and taper bearing in the housing.



Hope that helps.

[andy10v]

All the 01A exploded gearbox parts diagrams I can see in vagcat if it helps any.

[diesel des]

Ahhhhh I had assumed this was a 5 speed 01e?

[andy10v]

I think its a stock 3B 01A ARV unless he has changed it.

[andy10v]

Tonks started taking an 01A apart, maybe see if he got any further?

http://www.s2forum.com/forum/showthread.php?t=73082

Manual, just need to work down the links on the left hand side, and keep closing the pop up

http://workshop-manuals.com/audi/a4_mk1/power_transmission/5-speed_manual_gearbox_01a_%284wd%29/gearbox_mechanicsoperation_constructiondiff./dismantling_and_assembling_gearbox/assembly_overview/

[SteveH]

So I went out and took some pictures. Take the rear housing off were the prop shaft bolts on. It's just a few t45 bolts. The housing will come off with the shaft coupling. It's spring loaded so catch the spring and washer and shim. Then just pull the torsen diff out by hand.

Then you will see the oil seperator thing. It's brown plastic. Pop it out with a screw driver.



Then you will see a splined bolt behind it. It holds the input shaft tight to a bearing race.



That bearing part runs on a ball and taper bearing in the housing.



Hope that helps.

Brilliant, thank you

[SteveH]

All the 01A exploded gearbox parts diagrams I can see in vagcat if it helps any.

Looks bloody complicated, that's why I didn't want to crack it open! Thanks for the pics though

[SteveH]

I think its a stock 3B 01A ARV unless he has changed it.

Yup, 01A. Perhaps I should have mentioned that