Chevy S-10 auto transmission down shifts

JSCHUM

MEMBER
2010 CHEVROLET S-10

I have 1999 Chevy S-10, 2.2L, 151,000 miles with automatic transmission.
I had a transmission service and several leaks were fixed at my local mechanic. Since then, it downshifts around 70 mph (rpm goes from 2750 to 3500 and back and forth). There is no load on motor, it happens going downhill as long as constant pressure is on the accelerator. When I back off, it drops back to 2750, but will jump again when depressed.
Fluid level is fine. Any ideas?

1 Reply

SJTFDFIREFIGHTER354

MEMBER
5 POSTS

This is a characteristic of S10 transmissions. My Blazer 2.8 did it and my S10 extended cab 4.3 does it. It does it less when pulling a load (like the boat). I really don't think you can get away from this problem, except to give it more gas or less. I have been on this problem for 6 years. I've changed fluid and filter and vacuum lines and checked everything I could look at. I have talked to years experienced auto mechanics. They say, "OH yeah, S10 constantly shifting at highway speed.)[/Quote:4b6d837177]

>> my 2001 s-10 4WD does the same thing, but I really dont notice it until over 50 mph, it happens very rarely, but enough for me to notice it. I had a GM mechanic say that this was a common characteristic of S-10's, and I was not the first one he had heard this from. He had not heard of any major repairs necessary because of this