4L80E QUESTION???

Wrench Bender 2 · June 1, 2004

Just picked up 93 3500 454 4l80e 40,000 miles, I have a question, what temp. should this trans. be running at. Not towing just cruzn?

Thanks for your info!!

robsawatsky · June 1, 2004

Depends on the outside temperature, exact traffic conditions, and where you're measuring the temp. But my tranny temp at the output line from tranny to the cooler rarely gets up to 175 without a load.

snoman · June 1, 2004

As long as you are below 200 you are fine. Above 200, 220 or so is okay for a short time. When it gets above that you really need to back off. Above 240 your are stressing the oil and seals and around 280 to 300 you are flurting will slow death (I will not take too long) Much above 300, death is pretty quick. If you use synthetic tranny fluid it will take a bit more temp as the fluid does not break down as quickly with increased temps.

Wrench Bender 2 · June 2, 2004

Thanks for the info, I just plugged my scan tool and headed down the fwy at about 70mph, outside air temp 70, Scan tool reading was 203 I was thinking it was a bit warm or am I freekn out?????

Thank you all for your time,& advice

snoman · June 2, 2004

Thanks for the info, I just plugged my scan tool and headed down the fwy at about 70mph, outside air temp 70, Scan tool reading was 203 I was thinking it was a bit warm or am I freekn out?????

Thank you all for your time,& advice

If that is empty on flat ground and no towing is it a bit warm because if you do any of those it will surely go a lot higher. You might check out a after market cooler. Make sure you route oil thru stock radiator one first then thru aux one.

Wrench Bender 2 · June 3, 2004

I was thinking of mounting it between the AC condenser & the stock aux cooling fan, what ya think???

snoman · June 3, 2004

I would put is in front of A/C condensor (paint it flat black if you do not want to see it) and I would suggest a 13 x 6 size at minimum (or there abouts) . Run oil trough stock cooler in radiator first then thru aux one, not the other way. Do that and it should give you 170 to 180 cruises or lower without load and keep you at or under 200 with a load.

muleman44 · July 31, 2004

I have a 91' R2500 Burb and I put a large trans cooler between the fan and the condenser. My trans. temp. runs around 160 degs. in 95 deg. 90% humidity. I pull a 28' T.T. at 7200 lbs. the trans. runs about 210* in the same weather. I hope this helps