Denali transmission overheat

[JC007]

New Denali 400 miles. Trans overheating warning, temperature gauge pegged. pulled over temp went to normal within 5 mins, I was going over the grapevine in Ca (10 mile incline) was doing about 65 - 70 mph and was about 90 deg outside. This shouldn't happen, right? What if I was towing.
Anyone else experienced something similar or known issues? Transmisssion fluid smells burnt. It's now at the dealer.

[denalio34ceo]

Sorry to hear about that. My guess is low tranny fluid.

[tonytone]

Assuming that you weren't towing, then no it shouldn't overheat under those conditions. On my '04 DXL I've yet to see the tranny gauge needle hit 200, even while driving in stop-and-go conditions where the ambient outside temp is in the 90's (deg. F)...

[JC007]

Thanks for your replies. If anything there was slightly too much tranny fluid. Anyway the dealer just called and said that 4th gear is shot They are replacing the tranny. I'm not upset, I know these are great trucks (my 3rd Tahoe), things happen. I am concidering extended warenty though.

[denalio34ceo]

Wow, a new tranny at 400 miles. That sucks but that's definately the mfg's problem. It wouldn't hurt to ask for the extended warranty. They should make an exception for you since you've had a MAJOR problem. If not, there's always aftermarket warranties.

[JC007]

I guess the denali has 2 tranny's for the AWD stuff.
Has anyone been able to switch the AWD off without screwing anything up? I read somewhere that there is a fuse for the AWD.

[Vroom2]

Apparently there is a fuse, labeled '4WD'. I've been meaning to research this a bit, but haven't had the chance. It'd be nice to disable the system, but I'm concerned of the consequences... I'll follow-up if I'm able to find anything of value.

Take care,
Jerry

[JC007]

Great,
Thanks very much.
John

[tonytone]

Okay, I tested the 4WD fuse theory out--according to my unscientific findings (e.g., SOTP, butt dyno, etc.), my DXL seemed to feel slightly underpowered after I pulled the fuse; plus, the instant fuel economy reading on the DIC dropped to the point where I was having a hard time getting it to read anything higher than the mid-20's--IIRC--even while cruising (e.g., very little on/off throttle application in top gear). Again, all of this is purely unscientific but if I were to guess as to why my DXL felt underpowered after I pulled the fuse--I'd say that it's due to the 40/60 front/rear power distribution--i.e., I don't think that removing the 4WD fuse would "fool" the PCM (and/or whatever else controls any and all tranny-related aspects) into redistributing the 40% to the rear, thus giving the rear full power...but then again, I could be way off in my theory. IOW--only the rear wheels are getting power, and it's only 60%.

Feel free to correct me, as I'm a bit curious myself as to the actual ramifications of removing the 4WD fuse.

[Vroom2]

Aww shucks, Tony. I was counting on you to have a full and complete answer.

I like the basis for your theory, but wouldn't that 40% have to go <i>somewhere</i>? Seems like there'd be some sort of effect - heat, vibration, something. ??

Take care,
Jerry

[tonytone]

Jerry--yeah I thought about that, and it would make sense. I dunno--all I know is that something about my truck just didn't feel "right" (as far as power was concerned) after I pulled the fuse. Maybe it was all psychosomatic...