transmission
 

My 94 full size blazer is having tranny problems. Need some help. When it shifts into overdrive the RPMs jump up a few hundred and drops back down. The tranny shifts fine no hard shifts or jerking. It does this if u ease on the gas. If you stomp it it shifts fine. Fluid levels are good. Any ideas what could cause this. Thanks for any help

You might what to check the vehicle speed sensor there also a black sensor up on the throttle body that helps control the shift can't remember the exact name

Any Update
 

I am having a similar issue with the transmission in my 98 LT 4wd. Did you ever find the issue?

Thanks,
Richard

No I ended up parking it till spring when I'm going to pull and replace the tranny because there so problem prone sorry I couldn't be more help if you figure it out I would love to know

They are actually very good transmissions and there are a few other things that can be checked. i would before I just randomly replaced the unit. Get the TPS checked first.

Checked the tps…the shear number of problems posted here with that tranny shows there not the best I would take the old TH350 any day

Have to agree with gregg, they arent bad trans at all.

It basically is a 4 speed 350. now they are just electronic. Thats why they are called 4L60E's. A modern 400 is a 4L80E