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4L60E transmission operating temp

19K views 11 replies 4 participants last post by  sanctuary 
#1 ·
I am installing a TCI transmission temp gauge to monitor trans health on long drives on Germany's roads, as well as going to the Ring. I know that 1994 models did not come with computer displayed trans temp, like the '95-96' models.

Does anyone know the normal operating range (low and high) and the max safe operating temp?

My transmission is original, with 126,000+ miles, and has never been rebuilt. I drive the car almost daily too, not just on the Corvette club outings.

Any help or suggestions would be appreciated. Thanks.
 
#2 ·
#3 ·
Ok my input would be to remember the auto tranny get's cooled by the radiator. On the AUX fan side. Your coolant temp is a good indicator of your tranny. If coolant is hot. So is your tranny and oil.

So you want a mint condition cooling system. First tell us what our current temps are oil and water. Second physically inspect the system. Third make any corrections to lower the water temp.

I have mine running at around 194-199 in very hot weather max and oil 208 max in 100 degree weather.
 
#4 ·
tranny temp

I personally feel that transmission temperature under 250 degree will probably be ok,but 200-160 would be great. If you go over 250 the oil breaks down and it no longer cools or lubes correctly. If you can use a synthetic trans fluid that would be better. I highly recommend Allison Transynd for use in GM cars and trucks. Its just a fantastic fluid. Remember there is no more DEXRON III fluid. The licence ran out December of 2006.Look at your fluid container it probably says "use where dexron III is required". It doesn't say its Dexron III. It could be colored kool-aide! DEXRON VI is actually the only fluid recommended by the General, but GM Allison developed Transynd fluid and its great. Read about it at www.allisontransmission.com......my 2 cents worth:thumbsup:
 
#5 ·
Thanks for the replies. Within the coming month I will drain/flush the coolant, install a cooler thermostat and change the transmission fluid/filter. I already had those things planned for, but I think I will go ahead with the transmission gauge installation. I understand that the engine coolant and transmission temp are closely related, however, I like the idea of being able to monitor the transmission temp directly. If nothing else, at least it'll make me feel better. I don't like the idea of guessing if whether or not the transmission is blazing hot. For example, last summer I went on a club cruise to the Black Forest region of southern Germany. After a bit of driving I became nervous about the transmission because the engine oil was reading 220+ and the coolant around 230+, at the same time not knowing how hot the transmission was. (Yes, I am well aware that the LT1 runs hot by nature)Regardless, I felt a bit uneasy and found that I was more concerned about the known and unknown instead of enjoying the cruise.

This year I'm trying to keep things cooler. When all the work is done I'll add the results to this thread, if anyone is interested.
 
#6 ·
230+ is overheating.

When is last time you cleaned out debris and changed coolant mix?

Also when was the waterpump done? They go around 100-120k.

Coolant temps over 220 should NEVER happen. GM does tend to build cars to run hot to get best performance and emissions. So some modding needs to be done, IMO*, to cool it down.
 
#8 ·
Yea the tranny fluid temp gauge is a good add on.

Your on the right track. Things to look for is debris always get sucked up into space between condenser and radiator.

Also you can remove old radiator and either clean it or get a new one. Get Delphi ONLY. Do not even chance any other radiator. And need connections for the tranny cooling lines that go into cooler in radiator if new one put in.
 
#9 ·
Waterpump was replaced 43,979 miles ago, in 2005. After that, I don't remember exactly when the coolant was flushed. I cleaned that radiator debris out last summer also. And, I cleaned the road grime off the fins on the transmission cooler. Like I said before, I'll be doing all this again but this time I'll also install a cooler thermostat. Luckily, the Black Forest cruise was the only time that things got that hot. But, all it takes is one day like that.
 
#10 ·
Flush that bad boy. No death cool either. Put 50/50 Yellow (prestone extended) back in.

Probably want to service the tranny fluid too. If running that hot it's probably cooked. Then again cleaning cooked out sometimes will screw the pooch (screw up the tranny). Again this is one of the times where you want to use GM's tranny filter kit not 3rd party IMO*.
 
#11 ·
Yeah, I have a AC Delco transmission filter and gasket kit on-hand. And of course I will replace the transmission fluid at the time that I install the temp gauge bulb into the pan.

As far as the coolant mix, I've read people's opinions on what they prefer to use. I'll do some research and go with the best that I can find, same with the transmission fluid. The auto parts store on base (military) is a bit limited. But they do carry Mobil Mercon V fluid and Prestone coolant.
 
#12 ·
By the way, I check the transmission fluid often and it isn't black and doesn't smell burnt either. Transmission always shifts good and hasn't given me any problems. As of now, no noticeable deterioration. But, I'm sure that stuff is getting worn. Can't have a 126,000+ mile tranny and not have wearing parts. So far so good.
 
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