700R4/4L60 guys click here

[BIG_KID]

i bought my 91 K1500 350/700R4 knowing it had transmission problems. The kid who had it before me tried rebuilding the trans himself. It has P R 1 2 3 no 4th. It just acts like a three speed transmission. No slipping anytime. any advise is welcome

 

[Chris Rogers]

so no lockup?

 

[BIG_KID]

That's another story, he claims it had lock up but I never confirmed it due to when coming to a stop the truck would buck and engine dies. Restarted the engine and put it in gear and truck lurched forward and engine dies again. I unplugged the converter connector at the transmission and it hasn't happened again yet. So actually two problems I would guess.

I've been reading and looks like 3rd and 4th use the same clutch pack, only in 4th it applies the 2-4 band. Maybe something in the 4th apply piston in the 2-4 band or valve body.

 

[Chris Rogers]

could be anything. trash in that one area could be a point, could be something left out too.

 

[91c150001]

No O/D at anytime? No matter the speed? In my truck I had replaced the transmission that had supposedly been dyno tested and shifted fine. In the truck it worked flawlessly but wouldn't go into fourth until nearly 80 mph. I swapped the governor on a whim and got fourth. Maybe try that. It's only $20-30.

Sent from my LG-H820 using Tapatalk

 

[BIG_KID]

Thanks for the advise. I'll try that when it warms up a bit

 

[brutpwr]

Sounds like the converter was locked all the time until you disconnected the harness. Could be a problem with the brake light circuit/trans harness or could be internal in the valve body would be my guesses. You need to get a good transmission and truck service manuals to better understand how it all works.