From smooth to limp mode and P0700 code

[Geotrash]

It seems to be an unfortunate thing with the early model 6 speed transmissions. I bought a 2007 Denali years back that had a trans warranted right at 100k. I bought it at 160k, drove problem free til I sold it at 227k

Fast forward to where I missed that body style snd bought a 2008 Denali again. This one had the trans replaced at 130k. Going good so far. It did get quite hot (210F) climbing some 12k peaks in CO. I took a proactive approach and let the truck idle for 15 minutes with the hood open to get temps back in the safer zone. Fingers crossed so far.......

+1 to Foggy's comments. 210F is well within the normal range. There is a TON of misinformation out there about transmission fluid temps.

In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

“General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. "

 

[Kp1980]

I know this is an old thread but I don’t want others to be blinded by the great looks of a GM reman with a 3 year 100k warranty. Replaced the 6l80 in my wife’s 15 Tahoe with a GM tranny at 113k miles and a cost of $4500. Today, stranded on the side of the road with the same codes. P0700,p0723,p0724 with 119k miles. Everything about this vehicle has been nothing but problems in the 2 years we’ve owned it. Can’t keep A/C working, electrical gremlins every time you drive it. Wish i would have done more research before buying this pile of junk. Oh well, back on the trailer and to the shop it goes again.

 

[OR VietVet]

Welcome to your first post. Thankfully you have a warranty. Did you have the entire vehicle inspected before you bought it? Tell me you did not just go off a CarFax. Bought two years ago, what is your maintenance procedures? Not saying you don't have a legitimate gripe but some info is missing.