I have a 2007 avalanche w/towing package . just got through towing 3600 lb trailer to eastern Sierras and trans warning message came on several times. Stopping and idling for a few minutes cooled it down to reasonable temps, but noticed one time when pointed uphill would not cool until pointed truck downhill. looks like fluid wasn't making it to trans cooler located in front of radiator. Is there a fix for this? Additional cooler or high performance trans pump?
Country: United StatesMake: ChevroletModel: 2007Engine: 350
Hello I'm Neal and I am here to help resolve your issue. If I cannot help I will opt out and refer your question to another expert.
I suspect that it was not that you were pointed uphill but that you were towing uphill which is a lot harder on the transmission and the engine runs hotter when it is working harder which in turn adds heat to the transmission also.
Are you towing in overdrive?
When towing uphill had tow button engaged and was not in overdrive. When it was pointed uphill, idling in park, trans did not cool at all in 10 mins, when jockeyed around and pointed downhill, started cooling immediately when idled in park.
There is more than enough pressure created by the transmission pump that being pointed one way or the other should make no difference in the flow of fluid through the cooler, unless possibly the fluid is low. The fluid is pumped under pressure and does not rely on gravity at all.
I cannot explain why being pointed downhill would make a diffrence in the cooling, did the engine temperature come down faster also?
Don't know about engine temp, was not an issue. I believe trans fluid (level was verified good) was not being pumped uphill to cooler in front of radiator until helped by gravity when pointed downhill. Is there an accessory cooler available or is what I have the "accessory" cooler.
You should already have an auxillary cooler, here is a diagram showing what it looks like.
While I am not doubting what you are telling me, as you are the one experiencing the symptoms, I have never seen or heard of this issue where the cooling of the transmission was affecting by the angle of the truck.
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Engine temp never got much past normal, but trans sure did. Trans fluid level was verified both hot and cold and was in the approved range on the dipstick. You would think that a 19 ft trailer should not cause such difficulty when towing, as it is well within chev's recommendations. What to do.........
How many miles on the truck? And has the transmission ever been serviced?
85,000, and fluid was changed around 60,000
I would love to help you on this but I cannot give you a good answer, so I will opt out. So far I have only asked you for more information and not provided an answer. I do hope you will rate me well if you are asked. I will not be compensated for the help I did provide. But by me opting out maybe another expert can help. I just do not want to give you a bad answer.