Hello - First poster here,
Let me begin by saying this post should never have needed to be written, but I accept responsibility for it. I have owned my E320 for 8 years, and the original trans was not the best when I got it.
My original M104 722 trans had fully lost reverse, so I located a reasonable used unit (correct 1995 model) to install. It was not guaranteed, but I believe it was sound. My local mechanic suggested I use another local shop to do the swap, and could receive his shop-to-shop rate for the work. I decided to go this route instead of swapping myself, on my back.
It was swapped without apparent incident, Maxlife Dex III was used and a new filter was installed, with the plans to do another fluid change in 5,000 miles to be safe. I did not double-check how much fluid the shop filled the transmission with when they handed me the remaining fluid in its container.
The transmission worked fine, much better forward than the former unit, and had decent reverse function and engagement.
Today, reverse acted up, acting as though it was engaging both reverse and forward gears at the same time, in reverse only. I checked the fluid level, when hot, and it had been overfilled. I had to drive 90 more miles to get home (have put 1,800 on the fresh install), siphoned out perhaps 2 quarts (!?!) of overfill, topped it up to the correct level with fresh fluid and prayed. I nearly cried when I realized they had overfilled the trans that much, and I hadn't checked their work. The fluid, only 1,800 miles, did not smell burnt, or feel like it had shavings in it, but was not fresh and red, and will be completely drained and a fresh filter installed in the next few days.
The current status is: reverse engages, cool and warm both, and the car rolls backward as it should. If I apply throttle, it feels as though forward gears are also engaging/trying to engage, it halts the car from moving, and applying additional throttle does nothing except cause some slippage. One time, it sounded as though their was something grinding, so I immediately stopped that line of testing.
Please let me know if there is anyone with any experiences in this arena, and if I may be able to simply replace some seals with the trans still in the car, or if I'm staring at another removal due to my lack of oversight and trusting nature.
Thank you