Transmission Popped out of drive and wont shift right
 

1988 420SEL 160k Trans popped out of drive on me yesterday (right near Richmond) and then ones I put it back into drive it began working ok. I checked fluid, was ok. Same happened a second time. Then I noticed it is not shifting into the high gear. At 60 mph instead of 2000 rpm I see 3000 and it doesnt shift up. When I put it into neutral and back into drive, all at highway speed, then it goes into the high gear. Does this sound like TransX might cure this or is this bad news?

dave

Sounds like a candidate for Trans-X, then save up for a reb't valve body (~$500); gov. assembly is also a possibility, but 420's have a VB problem anyway.

thanx BenzRepair
 

The Trans-X seemed to do the trick right now (one test drive). What is valve body?
Do you leave Trans-X in there or best to drain and change fluid and filter?

dave

Check the shifter bushings at the linkage to make sure it really is in "D" and not erratically going in "3". It's a simple check under the car that might be a simple solution.

Sounds like combination of shifter bushing and K1 spring problem. Poping out of the gear could be shifter bushing issue, is it your transmission lever to loose?
The second issue of not doing up-shift or flaring could be the K1 spring disc issue, a $15 part and 1-2 hour of labor should fix this. Do a search on both of these topics Here is link for K1 issues
http://transmission.articles.mbz.org/k1/
Good Luck.