i have an 07 tahoe lt, it has 72k miles on it and is on it's 3rd transmission. Original went out at 59k miles, the one they replaced it with went out after only 7k more miles at 66k. I am scared to go any where. I tow a ranger bass boat that total weight, boat trailer and gear would not top 3500 lbs. Vehicle is equipped with towing package and i use the tow mode when pulling. Anyone else have problems with the transmissions in their vehicles and what sort of help if any did you get from gm?

i live in west virginia and do tow up and down hills on interstate but this should really not be an issue, engine is the 5.7 v 8

 

engine should be a 5.3 with a 4L65e behind it, or a 4L70e behind it. Do you have a transmission cooler? heat is one of the killers on the 4L60e,65e,70e family. If you don't have one, I recommend puttin on one. When you put it in tow mode, do you ever use cruise control? Do you know what gears you have in the rear end?

 

You can hardly go wrong by having an Auxiliary Cooler on your Transmission as country has stated.

Many of the problems with the 4L trannys comes from heat caused by frequent down-shifting when Towing. If you're running in fairly hilly terrain, using 3rd gear can considerably reduce the shifting frequency. Contrary to popular belief, using 3rd does not always cause a decrease in MPG. Do you have any way to check the Temperature of the Tranny Fluid ?