Tranmission Shifting Problem (Solenoid?)

GMC JIMMY
Avatar
ERICCROLL
  • MEMBER
  • 4 POSTS
1996 GMC Jimmy, 4.3L V6, AT, 120,000 mi

It's doing some wierd stuff when trying to shift, but it is very sporadic (slipping? in and out). The only thing that is consistent is that it does not down shift on its own when coming to a stop; tries to pull out in high gear (once up to speed, it seems to run fine). Manually downshifting locks it in second, which is the default, from what I understand after replacing a speed sensor last year. After a while, it will no longer engage in reverse, however if I turn the key off and wait about 5 seconds and then turn it back on, it's fine for a short while (several minutes). I have heard that it is likely the 2-3 solenoid, but I don't know what that replacement entails.

Do you think that is, in fact, the problem, and do you think that a somewhat experienced mechanic can tackle something like that on his own?

P.S. I have made a donation, and am anxiously awaiting your reply. Thank you very much.
Jul 26, 2007 at 4:26 PM
Advertisement
Avatar
CLY
  • CERTIFIED EXPERT
  • 308 POSTS
It sounds like you are on the right track with the shift valve being the problem. You can remove the transmission pan and see all the valves. In the picture you see below the 1-2 valve is 367a and the 2-3 valve is 367b. I would pull the pan and use a volt meter to check the resistance of the solenoids. You should see that they are around 19 to 24 ohms when the motor is cool. If they are both fine then I would suggest replacing the wiring harness in the transmission.


https://www.2carpros.com/forum/automotive_pictures/86485_62792_1.jpg

I hope this helps... Cly
Jul 27, 2007 at 5:54 AM
Avatar
ERICCROLL
  • MEMBER
  • 4 POSTS
Thank you very much. I will be taking that apart as soon as I get back from vacation next week. Eric
Jul 27, 2007 at 7:58 AM
Advertisement