Reverse acts like neutral when engine is hot. All gears work great and reverse does when cold!

dezzer2324

My 2007 Yukon Denali acts like it is in neutral when shifted into reverse when the motor is hot, but drive and everything else work fine. There is a hesitation shifting from 1-2 gear but that's it. When it's cold it works fine and has all gears and still slight hesitation when going from 1-2gear. The dealer told me to replace the transmission but other forums and tech pages say it might be an easier fix. Advice please and thank you.

PF_Flyer

The hesitation in the lower gears could indicate the clutches beginning to fail in the torque converter, but I'm no expert on transmissions. Did the dealer tell you why you should replace the transmission?

Mr_Shiftright

Given the symptoms, I'd take a guess that seals/o-rings are worn or hardened internally and you're losing hydraulic pressure when warm. It could possibly be a valve body issue which wouldn't be as expensive as a rebuild.

Not much one can say from this distance---modern automatics are pretty complex and they need to be diagnosed and tested--both with scan tools and external pressure tests, and then visual inspection dropping the pan.

dezzer2324

PF_flyer they didn't tell me exactly what it was for sure other than the hesitation from 1-2 and the reverse when hot. So I am going to get a second opinion from another mechanic friend. Mr_shiftright that's what is confusing me too, I thought valve body or solenoid maybe?  I appreciate the feedback Fellows.  I'll keep you posted whenever I find out tomorrow what they think it is.

dezzer2324

Well after a second opinion they have confirmed the worse. That the transmission needs to be replaced. So yay! Lol thanks for your input on the matter. 

Mr_Shiftright

That's too bad. So what's the bill? Around $2k--$2500? Be sure to get a written warranty.