Trans slipping in first

[gxp revenge]

My Trans just started slipping in first gear on take off. It will not move at all until I put it in manual mode then it'll go but slipping badly this is a 2007 gp gxp any ideas?

[Scottydoggs]

its tranny time. aka rebuild time.

[SgtMarshal]

the gxp transmissions wear out faster. gm really should have built them stronger for that engine.

[Fivefingerdeathpunch]

If you're at or over 100k miles, that's a good bet that you need a rebuild or swap in a semi built trans to handle the power and heat.

I'd install a trans cooler after you get everything done to keep the temps down.