I have an 89 s15 gmc big v6 4x4 automatic. tranny does fine on short trips around town but drive it 30 miles or more and it will not shift right ,seems to start slipping when it down or upshifts. I had the filter and fluid changed. but it did not seem to help. Mechanic that changed it said the fluid had no metal in it and did not smell burnt. Any suggestions other than a rebuild?
89 s15 auto tranny problems
- Thread starter junkman
- Start date
3DCrawler
Well-Known Member
- Joined
- Sep 26, 2005
- Location
- Granite Falls, NC
I suppose you have a 700R4. It may have low pump pressure or might be over heating if the tranny cooler in the radiator is plugged up. Might want to try flushing the cooler. If you mechanic has a flush machine that would work best if not if you have an old external fuel pump you can just get a bucket and fill it with a few quarts of ATF and flush the cooler yourself.
- Joined
- Mar 20, 2005
- Location
- Morganton NC
One thing I always disliked about an auto tranny was the fact that when you changed fluid and filter, you didn't get all the fluid like you do when you change your oil. The oil change place here in town has a machine that they can do that. Pretty simple really. They unhook the tranny line going to radiator, and run the fluid into the machine. The machine then pumps new fluid back into the tranny. All the fluid is circulated and out comes the old, in goes the new. Torque converter and all. It even measures your pump pressure so you know if it's working good or not. The machines pump is 12V and they hook it to your battery! I thought it was pretty kewl myself.