1985 4x4 700r4

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Jeffrey Roberts

Junior Member
Joined
Jan 12, 2021
Posts
4
Reaction score
0
Location
Blue Springs
First Name
Jeffrey
Truck Year
1985
Truck Model
K10
Engine Size
350
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

Full Access Member
Joined
Dec 10, 2022
Posts
51
Reaction score
103
Location
Nevada
First Name
David
Truck Year
1989
Truck Model
K5
Engine Size
350 TBI
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

Full Access Member
Joined
Jan 8, 2018
Posts
2,338
Reaction score
3,571
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
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

Junior Member
Joined
Jan 12, 2021
Posts
4
Reaction score
0
Location
Blue Springs
First Name
Jeffrey
Truck Year
1985
Truck Model
K10
Engine Size
350
Thanks. It has less then 100 miles on rebuild. I will try what you suggested. Thanks again.
 

scubacarib

Junior Member
Joined
Jan 24, 2015
Posts
12
Reaction score
1
Location
bastrop tx
First Name
john
Truck Year
77
Truck Model
c15
Engine Size
350
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
You must be registered for see images attach
t
 

Latest posts

Forum statistics

Threads
41,857
Posts
903,628
Members
33,370
Latest member
mitchell1128
Top