juspassinthru

2000 Silverado with 4.3 engine....112,000 miles
Under moderate acceleration the 1-2 shift is quite hard. All other shifts seem normal. Normal acceleration the 1-2 shift seems normal.
Any ideas.

08chevy262

My 08 does the same thing sometimes between 1st and 2nd. I think its common because all my my friends 2000 and up do it.

juspassinthru

Thx for the info.
I was told there is a pressure modulation valve/sensor that could be faulty.
Just checking if anyone knew something about it.

OLD WRENCH

Change the fluid and filter, and add a container of "Lube Guard" While I am not a great snake oil fan this stuff works. A lot of the trans shops in the area put it in on every rebuild. It wont repair broken or worn parts but if they are varnished up it will help.

Chevrolet Customer Service

juspassinthru and 08chevy262, have either of you gotten your issues resolved yet?

Jeff Morris, Chevrolet Customer Service

Hunt4X4

i have the same issue and have tried to diagnose it for years, i bought a new jasper transmission after mine finally broke and checked the conition of the rear differential, and even the transfer case. but even after the new jasper i still had the issue. i finally figured out that the driveshaft was the issue. the connection was loose on the rear diff. U-joint could also be the issue, though it is not with mine