jfrahm

On an old beater of mine I cut the wire that engaged TC clutch lockup when the TC clutch started slipping. This causes some loss of highway MPG but it kept going OK for a long time and the car was not worth a proper repair.

I have no idea if this is possible with the 5HP24 though.

silverd2

Disconnect upper trans cooler tube on radiator and pour it in ... easy.

jfrahm

Having thought about this I wonder if the trans might be operating at lower pressure than normal and unable to lock the converter properly, i.e. main pressure control valve? Is it slow to shift to 4th when cold?

Overall I think if you pay shops for stuff like trans fluid additions there is no way you should try to keep the A8 into the era where it'll need a fuel pump, axle boots, axle seals, front end parts, etc. An intrepid DIY'er might do great with that car but someone who pays shops for everything would be better off buying an old LS400, buying his mechanic a boat, and setting the A8 on fire.

That might sound crazy (and it is) but my point is that it's a better strategy than putting ten grand into the A8 over the next 5 years.

-Joel.

spitanddirt

+1

I just turned over 234k miles and I do mostly highway driving. It still slips out of 5th when in manual and traveling up long steep hills. As long as it's flat, it stays locked up. I've been nursing this issue for at least the past 30k miles. I want to pull the tranny and do a rebuild, but I can't seem to find the time to do it. To many "irons in the fire" right now, I have to keep nursing it for a while longer. I can say that the worst time that I feel the shudder is during light acceleration from 30 to 40 mph. It almost always wants to shudder right at 35 mph and shift into 4th waaay to early. Lockup can be harsh. Using manual mode to hold 3rd gear until I hit 40 mph usually keeps it from shuddering. I just changed my tranny fluid about 4k miles ago. That makes it 6 times I've changed the fluid since I have owned the car. I plan on driving this car until the wheels fall off. Engine still runs very well for it's age. I've performed two timing belt changes on this car since I've owned it.

Last time I changed my tranny fluid, I should have snapped a few pictures of the pan and magnets as they were very full of metallic particles. I can't keep nursing this forever as something has to be near failure with that much metal in the pan.

Joe Pasquarello

Thanks to all suggestions.
Trading it or selling it appears to be out of the question...its just not in me to basically give it away...its too nice of a car.
I found an indy who will install a rebuilt TQ for a reasonable price. So I am going that route and selling/trading it fixed. I'll get a couple grand more for it. Then I'll keep my eye out for a low mileage Passat.

jfrahm

Well at least do the TransGo fix it it fits that particular 5HP24. If that is your plan I'd install a later FUN-code trans and TQ, used/good, and do that valve fix on that one. I think you'd have a higher probability of success and your costs are mostly labor.

While you are at it do the tailshaft seal and axle seals as well as the CV joint boots (super cheap and easy to replace with the axles out). Front wheel bearings if they have not been done.

-Joel.

Joe Pasquarello

I'm only going to do the bare minimum to take care of the shudder problem then either sell it or trade it.
I got a competitive quote to just replace the TQ.
Thanks again for all the input.

jfrahm

Right but will that fix it? How come TC clutches do not seem to wear out on other D2s? If the root cause is not enough engagement pressure on the TC clutch you'll just fry another one. Obviously your big cost here is labor.

i.e. :
https://www.audiworld.com/forums/a6-.../#post24183694

That's a 5HP19 but you get the idea.

Joe Pasquarello

I don't discount the valve body could be an issue but the trans shifts fine from 1st to 5th.

jfrahm

When I had pressure regulator problems I really only saw a slow 3-4 shift in quite cold Colorado weather, FWIW. Occasional rough TC disengagement. Your local weather may be a factor, garage temp, as might the layout of your neighborhood possibly allowing warming up some before needing 4th gear.