HELP!!!! `87 420 SEL trans. problem???
 

Hi All: I have a `87 420 SEL. While parking the car, the trans. "magically" went into neutral in every range! There wasn't any prior problems/warnings. What's going on???

I removed the trans., replaced all the seals, etc., the reverse clutch lined plates, re-installed the trans......all gears still neutral!! What is the problem???? HELP!!!!

Thanx in advance.......
Glenn:confused:

Reverse gear is out also?

That's correct...reverse is non-functinal too. All positions are "neutral."

no tranny gears?
 

The first step is to check the hydraulic pressures to determine if the oil pump is working properly. Either the pump failed somehow or a disconnect in the shift linkage/valve body or pressure regulator circuit.

When I had the trans. out of the car, I checked the pump...it is good. Also, when I reinstalled the trans., it "sucked up" the new fluid quickly/easily. I don't have a means to actually check the pressure, but I feel like the pump can be ruled out. I think that it is most likely that a valve in the valve-body has "hung open"...mainly the Hi valve.

When I had the trans. out, I found that the lining on the reverse gear lined plates had been coming off. I replaced them. Maybe a small piece of that material found its way into the valve body???

What can I do??? How can I check that for sure???

Glenn

Did you replace the hidden O ring in the two clutch packs? They get hard and stop sealing then you have problems.

Yes, all seals checked and replaced...all the seals were pliable and in good condition...that's not the problem...HELP!!


Glenn

UPDATE!!! 11-03-02, 1:10 P.M.

I removed the valve body...I discovered (so far) that there is a broken spring in one of the valves. It is the valve directly under the SHIFT VALVE. (Actually there are two (2) springs--one fits inside of the other...the larger, outside spring is broken)

Does anyone know what this valve controls???

HELP!!

Glenn

UPDATE!!!! 5:00 P.M., 11-03-02
 

Hi All: Well, THANX for all your help/suggestions/direction...the trans. is working BEAUTIFULLY!!!!!!!!! As I informed all earlier, there was a broken spring in one of the valve bores. It's Sunday...no parts...about 2.5 coils were broken off...I reinstalled the same spring, but I reversed its direction (putting the broken end into the plastic valve rather than into the housing bore). The trans. shifts better than it ever has...got 265k on this one.

By the way, if I have to go in there again, it's a pretty simple job...I will drive it like this for awhile.

Thanx again All,
Glenn :D