I saw a post by frenchtranstech regarding the problems with the AL4 in a Peugeot forum. He said the main problems with the AL4 tranny were dirty oil cooler, dirty oil cooler, and leaky damper piston. I wonder if I have that latter problem. I recently purchased a 2000 Xantia with the AL4. It suffers from a bang or lurch when departing from a stop about 1/3 the time, otherwise the tranny works great. on departure from a stop, I have to feather the throttle for a second or two to let it bang or not, then depart. This high mileage tranny has had a lot of oil changes in its past life I am told; I myself have done two using Nulon full synthetic multivehicle which is said to conform to LT71141. I've wondered about fluid level, but find the fluid level setting procedure to be ineffective. Letting it drain till it stops (center bolt out, engine idling and 60C), way too much comes out, judging by the banging in the shifting afterwards, so I reproduced the old quantity. Better. It has BW solenoids, new valve solenoids, a clean control body. A Lexia says it have a slightly low idle neutral pressure but a good idle drive pressure. No fault codes. No idea regarding the firmware version in play. An internal leak seems likely, possibly also with fluid level problems. No limp home events.
I would bet others have had this problem, and perhaps someone knows how to fix it.
Would anyone have an idea what causes this banging into engagement on departure from a stop when all the while in D?
If it's the damper piston, it would be great to be able to fix it without removing the trans....