yet another "No Overdrive" thread

[tysandiego]

92 2wd 4dr 180k

I was driving @70 on the freeway when my X bounced me out of OD. All other shifting before/after is normal, just no OD.

Fluid level OK. Dropped the pan and there was quite a bit of sludge on the magnet in the pan, bad sign? Replaced Vacuum Modulator...it had fluid in it. Still no OD. After searching this forum, an awesome site btw, I read another possibility is the 3-4 shift solenoid is clogged and or dead. My question is: Where is it? Please tell me it easier to get to than the Vac Mod.

 

[MrShorty]

3-4 shift solenoid is in the valve body. I've never had to access the vacuum modulator so I don't know which is harder, but the valve body isn't too bad. Drop the pan, pull the valve body, split the valve body, fix the solenoid, reassemble valve body (getting all the little pieces in the proper place), replace valve body (making sure to get the right bolts in the right holes), replace pan, etc.

However, before I went messing with the valve body, I'd make sure the 3-4 shift solenoid circuit is functioning properly. Power to the solenoid (can be checked at the transmission)? Continuity between the solenoid and the computer?