AUA Help Required

birtyA2

Member
Dear All

Can anyone help please. Whilst doing some odd jobs today I think I located the gearbox drain and filler plugs ( sorry still a bit new to this and finding my way around ). So the picture below was taken from the offside close to where the drive shaft connects.

D02E9104-4534-4D82-93D4-DC75070F7513.jpeg


Bit difficult to tell but they look slightly different sizes to me but from what I have read they should be the same size

So my question is, have I located them correctly on a 2001 AUA. I’m contemplating a gearbox oil change and thought it might be best to order up new plugs before doing this.

Also is the correct part number WHT001937

Many thanks in advance

Justin
 

Sylvester

Member
The one next to cv boot isn't the filler bolt, check the pic attached for the correct bolt.
But either way DO NOT undo the drain bolt!
Not at least until you undo the top refill bolt!

The oil should be for the life of the engine, so the refill bolt is almost impossible to remove, it's factory sealed! So if you drain the oil, which is oddly easy to remove, but cannot undo the refill bolt, you won't be able to drive. Unless you actually need to change it, advice is to leave it be.
 

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birtyA2

Member
The one next to cv boot isn't the filler bolt, check the pic attached for the correct bolt.
But either way DO NOT undo the drain bolt!
Not at least until you undo the top refill bolt!

The oil should be for the life of the engine, so the refill bolt is almost impossible to remove, it's factory sealed! So if you drain the oil, which is oddly easy to remove, but cannot undo the refill bolt, you won't be able to drive. Unless you actually need to change it, advice is to leave it be.
Ah, couldn’t have been more wrong if I tried, LOL. Many thanks for the picture that really helpful. I’ll have another look tomorrow. I had read to make sure I can get the filler out first. Do you not think that the gearbox oil will have started to degrade a bit now?

Rgds

Justin
 

Robin_Cox

Member
I've been advised here that it is possible to top the oil up through the hole where the reverse light switch goes - my local mechanic (who does buses and other large vehicles as well) couldn't shift the fill plug so I asked here and that was the response - it will be slow but it's the way to get it done. As our AUA is on very nearly 200k the gearbox feels as if it could do with a top-up (as oil has been lost over the years when the driveshaft seals were leaking).
 

steve_c

Grumpy OAP & A2OC Donor
Do you not think that the gearbox oil will have started to degrade a bit now?

Even when gearboxes are kept clean and dry, they tend to lose oil slowly over the years. My local indie VAG specialist advises replacing the gearbox oil at between 5 and 10 years old, depending on mileage.
 

audifan

A2OC Donor
That and the fact that some water will get in through the tower shaft bearing all equates to for "sealed for life" read probably 5-10 years or if a gearbox issue is suspected.
 

Olerype

Member
I've been advised here that it is possible to top the oil up through the hole where the reverse light switch goes - my local mechanic (who does buses and other large vehicles as well) couldn't shift the fill plug so I asked here and that was the response - it will be slow but it's the way to get it done. As our AUA is on very nearly 200k the gearbox feels as if it could do with a top-up (as oil has been lost over the years when the driveshaft seals were leaking).

Yes correct; that is also how Audi dealership refill oil through the reverse light switch
 

birtyA2

Member
Many thanks to all

Looking at the exploded diagrams it doesn’t look to hard to find the reversing light switch, I’ll have a look tomorrow. Certainly happy to go with Audi recommendations that this is the preferred way of filling, sounds like a plan

Many thanks again everyone for your help

Justin
 

audifan

A2OC Donor
As this method will allow you to put too much oil into the gearbox be sure the gearbox is fully drained and only put in the required amount of fresh Audi gearbox oil. The drain / fill plug method by design overflows if too much oil is put in the gearbox.


No3 being the reverse switch.
 

mtl

A2OC Donor
My mechanic just did this job two days ago on my AUA, MY2000 while replacing the clutch.
I planned to do it myself, but sadly I do not have enough time.
Here is the fill plug:
Transmission AUA.jpg

Interestingly my drain plug was different although when I bought one (just in case) it was the same as yours.
Drain plug.jpg


This is Audi transmission oil that I used:
Transmission (2).jpg


Difference between new and old. I expected worse after 22 years, althoug my car has only 109.000km.
Transmission (1).jpg



According to specs you need 1.9l of oil.

From my transmission only 1.1l of oil was drained out :eek: , but 1.9l of oil went in until overflow from fill plug. There were no leakage signs on transmission.

Hope this helps.

PS: After replacement of oil the shifting is much smoother. I ocassionally had a problem with engaging the 3rd gear (it was quite stiff), which until now has not yet reappeared after the transmission oil was replaced. And together with clutch replacement, it completelly transformed the driving.
Btw: my mechanic had no problems with removing both plugs.
 

birtyA2

Member
Many thanks to all for your help on this, I can now report that I have managed to change the gearbox oil. If it helps others in the future there are some annotated pics below showing the location of the possible drain and fill locations.

I opted to fill via the reverse light switch which is more accessible than the official top up plug which is really tucked away and I didn’t feel confident getting that far under the car. I got myself an oil syringe and 17mm hex bit and all went Ok with no drama.

The colour of the oil was pretty much the same as the pic posted by @mtl with no sign of water. As has been reported by others only 1.2 litres came out. I did select all the gears whilst draining and did manage to syringe out a tiny bit more. There was no signs of a leak.

I put 1.9 litres in via the removed reverse light switch. The gear shift is noticeably smoother thou I don’t know whether this is because it is fresh oil or that the amount is now correct.
 

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Well done. I reckon the improvement is down to the new oil. Same effect with mine which hadn't been serviced for 10 years when I bought him, What came out of the gearbox was beyond description.
 

Sylvester

Member
Many thanks to all for your help on this, I can now report that I have managed to change the gearbox oil. If it helps others in the future there are some annotated pics below showing the location of the possible drain and fill locations.

I opted to fill via the reverse light switch which is more accessible than the official top up plug which is really tucked away and I didn’t feel confident getting that far under the car. I got myself an oil syringe and 17mm hex bit and all went Ok with no drama.

The colour of the oil was pretty much the same as the pic posted by @mtl with no sign of water. As has been reported by others only 1.2 litres came out. I did select all the gears whilst draining and did manage to syringe out a tiny bit more. There was no signs of a leak.

I put 1.9 litres in via the removed reverse light switch. The gear shift is noticeably smoother thou I don’t know whether this is because it is fresh oil or that the amount is now correct.
What kind of syringe did you use?
 

birtyA2

Member
What kind of syringe did you use?
So I bought an Auto Jack 500 ml off the bay which came with some clear plastic tubing which was long enough to pump from the ground up and allowed me to suck out the dregs. No idea if it is considered any good but it got the job done.
 
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