1985 4x4 700r4

[Jeffrey Roberts]

I have rebuilt my 85 700r4 transmission. Replaced all seals, clutches, some steels and detent cable. It has 1,2 and third gear. Some times 4th and then lockup. I need some direction to go in to troubleshoot.

 

[Zelph]

I would look into the 3-4 shift valve/piston whatever it’s called and check it to see if it’s hung up.

 

[Matt69olds]

How many miles since the rebuild? If the 1,2, and 3 shifts are normal, with no other issues, put the shifter in 3rd gear, drive the truck at a speed well beyond where it would make the 3-4 shift, and put the shifter in 4th. If it shifts, upshifting/downshift a few more times. If the valve is a little sticky, sometimes that can free it up.

If not, pull the valvebody and check for sticky/hanging up valves. When you reinstall the valvebody, carefully torque the valves in a circular order. The early 700s overhaul manual outlined a specific bolt torque sequence, but most likely if you tighten them evenly and correctly you will be fine.

 

[Jeffrey Roberts]

Thanks. It has less then 100 miles on rebuild. I will try what you suggested. Thanks again.

 

[Jeffrey Roberts]

Thanks Z.

 

[scubacarib]

i have found Lucas transmission fix works wonders i put it in every build this is a pic of the one i use they make another but i have only used this and it works

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[Jeffrey Roberts]

Ok Thanks