I've been driving my new(to me) automatic 5cyl. 4000s for two weeks now and am enjoying it very much (i've been driving a 3/4ton ford 6cyl van for 5 years, now you can understand why). I changed the trany fluid a week ago because it had never been done and the car now has 60000kms on it. Just a question about the transmission, i'm not concerned about increased performance or anything, just reliablity. Does anyone have reliablity information for this trany? Should i study up on how it is removed for repair or will it last, with regular maintenance, of course? going to change the timing belt and water pump this weekend. Got all my big sockets and breaker bars ready....

Mines gone south.

Swapping it out for a 5 speed manual.

When my aunt owned my car, it had to be replaced at 40K! Amazing, but, I havnt had any trouble with it since ive had the car.

After how many miles(kms)? Is the 5 speed conversion difficult(after finding the appropriate transmission)?

Varies greatly. Depends largely on how the transmission was treated over its life. They seem to go, if their fluid is neglected, or they were
pushed hard too many times.

Audi has done improvements over the years to the newer generations of automatics. Reviewing design schematics you can see the improvements over older designs. Larger bearings, twin bearings, better seals, etc. However the transmission clutch & brake disk plates still remain problematic. They are improving though! The A4 auto's(96 & up)are even better than previous designs.

Maybe one day they'll get it right.

In the mean while, all Audi "sport"(S, RS) models have manual gearbox's. Their just more durable and can handle much larger amounts of power.

Converting to a manual trans is quite a project, and varies considerably between years & models.

I have about 4,000 miles on it so far, no problems. It's a large job.