2nd to 3rd gear flare

[06LTZ]

I noticed my Suburban has started to flare on the 2-3 shift. It has the 4L65E transmission. I've searched and read some conflicting information. So far, I've read that its a pre-cursor to a rebuild. I've also read it can be remedied (or at least improved) with the Corvette servo. And somewhere I read that clearing the adaptations helped.

Any advice on this? Money is tight, I don't have the budget right now for a rebuild. I hesitate to start experimenting because I don't want to exacerbate the problem.

 

[dantheman]

man my experience with the 4l6xe model transmissions is once they start going, its time for replacement. getting one from GM isnt that expensive either. i was able to get one for around 1900 after the core charge was given back. 3 year 36k mile PARTS AND LABOR warranty. that warranty was what sold me on it.

i played with a built one from a local shop thats nationally known (century transmission) and it lasted me a grand total of 1400 miles and 15 months in a 330 wheel hp GTO. was supposedly good for 500hp. yea right. the worst part is they said "well you are outside of your warranty (12 mo 12000 miles) so we might work with you on parts." Screw that noise. that build cost me almost 3300 dollars. i was born at night, but not the night before that phone call.

IMO start saving for a reman from GM. id trust circle D with a build but i wont ever expect a 4l6xe trans to hold anything over stock HP for long.

 

[sumo]

You can try trans non slip like Lucas. May help but it's only a band aid. Have you done a trans service? Notice a bunch of metal fragments stuck to the magnet?

 

[rockola1971]

The "corvette servo" is for the 2-4 band. The 2-4 band is releasing (NOT ENGAGING) for the shift to 3rd so your problem isnt 2-4 band related. My bet is you have a sticky valve in your valve body. Should be an relatively easy fix and wont require a trans rebuild. I would find a known reputable shop to check and fix it. Many of the not so honest ones, the first thing out of their mouths is "Yeah, it needs a full rebuild". Walk away when that happens.

 

[06LTZ]

Thanks for all the help! I spoke with a shop today about a trans service with new filter and flush the cooler and lines. Anyone done this themselves? How did you flush the lines and cooler?

I realize this may not be a fix but its a starting point.