Transmission problem in reverse

[tinyfootprints]

I have an '07 Sierra 4wd and the tranny started acting up this week. When I put it in reverse the truck will start to move backwards but if I give it some gas the tranny seems to slip - the truck feels like its in neutral and the rpms go nuts. this only happens intermittently - twice in the last couple of weeks. Anyone else have this happen? Wanted to get some advice before I take it in to the mechanic.

[Carder09]

Kinda like yours but what I did was put it in reverse and immediately stomped the gas

And the rpms shot up then it finally engaged hard and off I went. Was pissed so probably will never do that again. Oh and the engagement took less than 2 seconds if not sooner since it was almost automatic but like before had already put my foot into it.

 

[aflesch]

Check to see if you have engine braking in manual 1st. That can really help narrow down where the problem is. Most likely the low/reverse clutch is shot and you need a rebuild but there are also a few other things that could cause it.

[tinyfootprints]

Thanks for the advice - manual 1st seems ok. I'm taking it in this weekend to have a mechanic take a look.