What transmission temps are normal
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 1,223
Likes: 4
From: Regina Saskatchewan
What transmission temps are normal
I'm installing a 3200 stall torque converter this weekend. I picked up a tranny temp gauge from an '82 a few years back and never installed it (but will now) What temps are normal / high and whats 'shut er down' ?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Basically, you don't want to 'cook' the oil. Depending on what kind of trans oil you use, that could be between 240F to over 300F. I think the "desirable" operating temps for an automatic trans is in the area of 190F-220F. If you see temps of 220F or more under normal operating conditions, your cooling system needs some help.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
When I went to mechanic school back in the '80's, the Auto trans teacher taught us that ATF (mineral oil based) turns to varnish above 230F. (why it changes color and smells different). Once it changes to varnish, it dissolves the clutch linings and hardens the seals. So we were always taught keep it around 220 deg. F.
Not sure about the new ATF compounds and synthetics, but that is my rule anyway...
Not sure about the new ATF compounds and synthetics, but that is my rule anyway...
Melting Slicks
Joined: Feb 2009
Posts: 2,797
Likes: 608
From: Dallas Georgia
2020 Corvette of the Year Finalist (track prepared)
C3 of Year Winner (track prepared) 2019
I have a 4000ish (albeit lockup) converter in my 4l80 and I typically never see temps above 185. This is with the trans cooler in the aluminum radiator with a plate cooler in line mounted to the front.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
For those folks with automatic transmissions, this brings up the old issue about engine operating temperatures. Some folks think that 220F or so is fine to operate their vehicle. Well, the transmission is cooled using the same cooling system as the engine....so temps in the two will be close to the same. If you run the engine at 220F and the transmission is running at the same temps, how good is that on the tranny fluid??
If you are in this situation, you may want either to cool down your engine/cooling system....or put synthetic tranny fluid in the trans.
If you are in this situation, you may want either to cool down your engine/cooling system....or put synthetic tranny fluid in the trans.
