Hi I have a 1988 GMC S15 JIMMY 4WD base model with a 2.8L v6 and it has an '86 700r4 or 4L60 transmission. Recently the front pump went on in that transmission, so I decided to replace the whole transmission which is easier for me. So I got another transmission (used '88 s10 blazer 700r4 or 4L60) but in great shape and running condition, and I have proceeded to install new torque converter seal and the filter...... which I have the correct filter, I have removed old o ring from tranny, but I still cannot get the filter to properly seat. So I try to put the tranny pan back on, I tried and it "rocks." So I'm assuming the filter isn't allowing it to bolt on properly because it's not seated all the way. The valve body is different on both transmissions, not sure why. And I have researched the case numbers on both, and I have done some extensive research to figure out what the issue is. I always come to a dead end. Does anyone have any advice? I'm at a loss, I don't know what to do anymore.

 

The pan is not bent up in the center from using a jack on it? Did you drive the new filter seal in the pump before trying to install filter?

 

I had to heat up the o ring on the filter before I installed it, made it alot easier for it to slide in properly. It's cold here still, so the o ring wasn't sw
seating all the way. But one I warmed it up with my lighter, it slid in real quick no problem at all.