1986 Other GMC Models 400 to 700r4

MATTOEC

MEMBER
1986 GMC

Transmission problem
1986 Other GMC Models V8 Four Wheel Drive Automatic

I bought a 700r4 to go in my 86 suburban 3/4 ton 4x4. My truck has a th400 in it right now. What will I need to change to make this new tranny fit in my truck. The 700r4 came out of a 1/2 ton 4x4 the splins should be the same, right, is there a driffrent adaptor I need to get to match it up with my transfer case.I do know the filler tube is diffrent and so is the speedo cable. Will I need to move the mount on the transfer case?Will my converter work in the 700r4. What else should I look for that might need to be changed? Thanks Matt

1 Reply

2CARPRO JACK

MECHANIC
11,533 POSTS

Dipstick, crossmember, t-case adapter, torque converter, flexplate (unless yours has both bolt patterns in it already), you will need a TV cable (throttle valve) and the bracket to mount it on the carb or TBI unit, the vacuum switch for the lock-up converter, new driveshaft yoke (where it goes in the trans) maybe the front section of the rear driveshaft shortened a little bit, shifter. After it is in, a speedo shop can handle the adapter and calibration for you