I have read the threads about the trans heating up and at this point I am wondering if I may actually have an internal issue. This truck has 150K on it and has just gone down the freeway most of the time but about a dozen times towed a 12.5K 5th wheel for a month a year also. I know how to drive it and have always used tow mode plus manual and not pushed it up hills. It has always run hot from day 1 and even in cooler ambient temperatures. All stock except I made braided lines to replace the rubber cooling hoses. When it gets hot almost nothing will cool it down except idling. Down hills higher rpm, no good. In fact it seems to even get hot when trying to use the higher rpms to brake downhill. By hot I mean just shy of the red. A few time I have it go into showing the temp was overheated and I stopped. I have changed the fluid twice, never dropped the pan and change the external filter every 10k. I use Transynd. So now I am wondering what to do next? I won't take it out next summer unless I have a plan to fix it and have that done first. TIA for replies.
2007 Classic LBZ, Trans. Heat
- Thread starter Don Dorfman
- Start date
Mike, I will pull the pan and see what I find, take a photo if anything.
I bought the truck new, it is 100% stock
I bought the truck new, it is 100% stock
I got the pan off and it was very clean as was the filter. No codes present or history. Now I am wondering what fluid to use. I heard a rumor that Transynd, that I had in there was not as good at transferring heat as Dextron. But all kinds of crosstalk about Dex VI not being compatible with all the seals and loosing viscosity stability. Being an engineer I take all of this as noise before I read a bonafide spec or listen to subject matter expert. Mike what are your thoughts?
Regarding the heat issue. I have one more thing to check. Years ago I replaced the trans cooling line hoses with AN style hoses, weld on fittings and steel braided teflon lined hoses. It is possible there would be some flow loss due to a smaller ID through the fittings. I will take this apart and investigate further.
Regarding the heat issue. I have one more thing to check. Years ago I replaced the trans cooling line hoses with AN style hoses, weld on fittings and steel braided teflon lined hoses. It is possible there would be some flow loss due to a smaller ID through the fittings. I will take this apart and investigate further.