I was at Walmart yesterday, and was getting ready to back out of my parking spot. I put it in reverse backed up about 5 feet, and the truck just stops. I put it in drive for a second, pulled forward about a foot, and put it back in reverse and it went another 6 feet then stopped again. It felt like it was in the rearend, but I couldn't tell for sure.

Is my g80 going bad, or is it something else?

 

I would guess it is either your differential or the parking brake assembly binding up.

 

Could be a reaction sun shell going bad? Symptoms: no reverse, no second or fourth gear.

 

It's an flt level5 thats about 6-7months old, so I doubt thats what's wrong. I don't think it has to do with the tranny because it still tries to move, but something in the rear won't let it.

I never thought about the parking break, I just did all new rotors, and stainless braided flex lines. Maybe I'll take them back apart just to see.

 

I 2nd the differential.
When it stops. Does it roll to a stop like its in neutral or does it act like you just hit something and come to a dead stop?

 

It feels like I hit a big rock or something, then when I put it in neutral it coasts forward about six inches to a foot.

 

check caliper bolts (just in case). if you lost one, the caliper could shift when moving in one direction or the other. could be fine in drive, but shift in reverse & binding against the rim. had a cousin that let a "shadetree" shop replace pads and rotors on an old Lumina. I drove the car while he was out of town, and guess what bound itself to the rim...

 

I've seen tons of rear caliper brackets come loose and bind up against the rim... Always put lock-tite on them and tighten the hell out of them.

 

Well, I think fossil was sort of right, I di some investigating it isn't the rear end, or brakes. When it does it if I put it in N it feels like it want to move forward, so I revved it a little and at about 1500rpm it grabbed and barked the tires a little. I called flt and Vince said he thinks it's something to do with the 1st gear clutches. So after I talked to him I went out and logged some with hpt and it says it's shifting to 3rd when I put it in R, but only after I drive a little bit. If I just jump in start it up and put it in R it works just like it should.

I'm gonna yank the pan and see if I can tell if anything is burnt, and probably end up shipping it back to get it refreshed.

 

sounds like the front planetary to me. of coarse i just had the same thing happen two weeks ago