Ok, here is the base of my thread. I have been having some issues with the transmission fault light(amber) coming on and causing the trans to lock into the specified gear the light came on into. In low RPM's and low gears the trans would shift hard almost like dumping the clutch early in a manual is the easiest way to describe it. Never did the car throw a engine light but finally after some time it did! Pulled up a speed sensor related code. Got to surfing the web and local trans shop to come across Transtar which has a remanufactured valve body for our XJR's so I thought "woohoo" $600 bucks and I ll be done with my issues. Well, no. That didnt happen because as it seems they must have discontinued the part, they only had one, and it was $900+ so went ahead and replaced the conductor plate/electrohydraulic unit with current MB part. Made sure all the springs and valves were free and not broken. . Upon reinstalling and topping off fluid the car is running without issue for now. I have a few questions for those who venture this far...

TCM unit, what is the best/easiest way to reset for adaptions?
I was suggested to pair the negative and positive cables together...obviously disconnected from the battery.

Also, if this isnt the problem...do they make a rebuild kit for our XJR's valve bodies? Like springs, valves, screens...

I hope this can help people in the future with identical problems or save some money. I will add MB part numbers and some additional info soon.

 

Adaptation reset is accomplished using the dealer software or equivalent. Search on mongoose on these forums.

Now, was it the valve body for sure? Or, low fluid that got topped up during the install?

 

Im a little confused on your question...
I do not understand how I could just top off fluid if the valve body was removed and re-installed.

I have done fluid and filter changes in the past since Ive owned the car because the electronics gromet was leaking when I purchased the car. So I have done it twice in the last 6 months to get the fluid close to 100% without draining the drum. This would make number 3 due to the fact that the speed sensor/trans issue popped up. Fluid levels are correct with proper fluid.

Researching MB websites on the 722.6 pre 2000's used a different valve body and regulator springs were different as well. In the MB's, the main regulator valve often times broke but this is not my case. After cross referencing a lot of the NAG1 stuff it appears to be more like ours trans. Others on this forum has run into these same symptoms and replacing the valve body was the solution. DIY MB guys on the forums usually replaced the conductor plate and solved their issues so I gave it a whirl.