Max Chevy Trans Temperature

[herk7769]

Maximum transmission temperature

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. "

[Traveler II]

Good to know Lou, I was told by my dealer to keep it below 212. Glad to see there is some leeway.

[hoffkm]

270 degrees initially seemed a little high to me as I have always targeted a maximum of 200 degrees on my fluid temp. In the machines that we build at work we target 150 degrees for the hydraulic oil and have problems when we get up in the 190-200 range with varnishing of pumps and valves. I did a little research thinking that maybe GM was referring to new vehicles that are utilizing synthetic oil as all GM trucks do since GMT 900 in 2007 (much higher operating temps than traditional "dino" oil). I found that transmission oil starts breaking down prematurly at temps above 175, damage occurs above 300 to internal transmission components, and as high as 275 is allowable for all transmission fluids. However, it you run temps above 175 (as we all do towing our rigs) more frequent fluid and filter changes are required as outlined in the following chart (validated from a couple of sources):

175 degrees change every 100,000 miles
195 degrees change every 50,000 miles
215 degrees change every 25,000 miles
235 degrees change every 12,500 miles
255 degrees change every 6,520 miles
275 degrees change every 3,125 miles

Sorry for all the boring data, guess it's the engineer in me coming out.

[acadianbob]

LOVE the engineering data! Very useful. I rarely exceed 160 degrees on my F150 though. Exception is a 10 mile climb of 5 go 10% in the mountains. Then I see 205 by the end of the climb.

[crocus]

I put the biggest tranny cooler I could find on our TV, and the temp never goes over 160, usually around 135. No sense cooking the oil in a vital TV component.

[bikendan]

i'm interested in this discussion.
i have an '07 Avalanche, with factory tow package, pulling a 23' HTT that weighs a little over 5000lbs.

i've had tranny temps around 225 degrees for short climbs.
i've wondered if this was normal. the factory tow package has a tranny cooler in it.

[mtnguy]

Originally Posted by acadianbob

LOVE the engineering data! Very useful. I rarely exceed 160 degrees on my F150 though. Exception is a 10 mile climb of 5 go 10% in the mountains. Then I see 205 by the end of the climb.

My temperatures are simaliar......imagine that since we have the same truck stats.

Check out this thread: Transmission Temperature Chart

That new Google search engine at the top of the page works sweet.

[herk7769]

Chap, that is why a started a new thread and "stuck it" This was the first time I had ever seen the "maximum" temp confirmed anywhere. The DIC warning comes on at 250 and you should take quick action to pull over and cool down before continuing.

[hoffkm]

Originally Posted by bikendan

i'm interested in this discussion.
i have an '07 Avalanche, with factory tow package, pulling a 23' HTT that weighs a little over 5000lbs.

i've had tranny temps around 225 degrees for short climbs.
i've wondered if this was normal. the factory tow package has a tranny cooler in it.

The factory tow package transmission oil cooler is no more than the stock cooler that flows thru the radiator. Before I towed anything with my 2007 Avalanche I added the GM auxilary cooler in front of the radiator. With this my trans temp runs between 170 and 190 pulling my 2901SS and may get to 200-205 if I am pulling up an incline. An aftermarket cooler may work even better than the GM accessory item.

[rockwood06]

I had posted this chart a while ago, it shows the break down of the trans as the temp increase over a period of time. I have a read out on my truck that tells me what the temp are on the trans from the factory.