Tranny slip or engine miss?

[Millennium1]

I looked at a lot of the previous posts but didn't see anything like what I'm experiencing. When I'm driving at a steady speed, usually 45-50mph and start up a hill or try to speed up slowly without romping on the pedal, my truck jerks like the transmission is slipping. This only happens when the rpm's get down around 1000-1200 and right before the trucks shifts. Once it shifts and the rpm's kick up the truck runs fine. This only happens when the truck is about to shift, which is also when the rpm's are low. I don't know if I have a low idle miss or if the torque converter is sticking or what. When the truck jerks or shutters the rpms do not jump around at all.

I have a 99 Silverado with a 5.3 liter engine.

What do you think?

[kenny-1907]

It sounds like the lockup in the trans. Next time it is doing this , tap the brake pedal just enough to activate the switch but not enough to actually apply the brakes and see if this causes this problem to stop. If it does it is caused by the trans lockup, which is seperate from the overdrive. As for how to fix this problem , i do not know. I was wondering if you had oversized tires on your truck though.

[Millennium1]

No, just normal sized tires.

[busta]

well i'd say HIT THE TRANS SHOP A.S.A.P most have free advise that can save you thousands.. good luck

[usafflyboy8]

Originally Posted by Millennium1

I looked at a lot of the previous posts but didn't see anything like what I'm experiencing. When I'm driving at a steady speed, usually 45-50mph and start up a hill or try to speed up slowly without romping on the pedal, my truck jerks like the transmission is slipping. This only happens when the rpm's get down around 1000-1200 and right before the trucks shifts. Once it shifts and the rpm's kick up the truck runs fine. This only happens when the truck is about to shift, which is also when the rpm's are low. I don't know if I have a low idle miss or if the torque converter is sticking or what. When the truck jerks or shutters the rpms do not jump around at all.

I have a 99 Silverado with a 5.3 liter engine.

What do you think?

Just curious to see if you came up with an answer to your prob. I have a 2000 silverado. And its having the same issues.

[rustcal]

My buddy had a 99 sierra and it was doing the same thing, got his tranny rebuilt and fixed the problem for about 6 months. He traded his for an 02 sierra. I can't remember what was broke but when we dropped the tranny pan it had metal shavings and pins in the pan.