MN8 : 4-speed HD Automatic Transmission- 4L85E Running Temps

[MPDano]

Hey all,

Got the full service for my transmission the other day. Full flush and filter and filled with Amsoil Signature Series Trans fluid.

I noticed driving to work, ambient temp around 65 degrees, the trans temp stayed around 160/165. I got to work around 25 miles away, ambient temp around 70, I see the temp staying around 185/190. Driving home it was close to 90 ambient, temp stayed around 185/190.

Is 185/190 a normal temp range unloaded? My engine thermostat is a 185. Engine always stayed nice and cool. Also, did the engine oil service as well. Royal Purple 5/30 and a new filter.

Still got the stock little trans oil cooler in it, which I will add another cooler in the near future.

Are my trans running temps ok unloaded?

Thanks,
Leo

 

[MPDano]

Here are the running temps while I was in traffic going to work. Ambient temp outside was 86 degrees.

 

[retiredsparky]

100* above ambient temperature is very common. Tranny and fluid is fine up to 220-230*. The fluid flowing through the radiator from the tranny dumps excess heat, but will stay pretty close to that 100+ambient after warmup. Wheel bearings, differentials when not towing run about 50* above ambient temp.

 

[MPDano]

100* above ambient temperature is very common. Tranny and fluid is fine up to 220-230*. The fluid flowing through the radiator from the tranny dumps excess heat, but will stay pretty close to that 100+ambient after warmup. Wheel bearings, differentials when not towing run about 50* above ambient temp.

Thanks for the reply. So I guess the real test is when i tow my Toy Hauler next week to the Desert.

 

[MPDano]

Well, she did real good this weekend. The trans flush with Amsoil seemed to do the trick. I was hitting 240-250 on some of grades before the flush. This time around, i was full of toys, at least 1500 lbs heavier and never saw it get over 215 degrees.

Still gonna put the extra cooler for more transmission protection.

 

[retiredsparky]

Good job-that high temp is ******* the fluid, and ******* the clutches

 

[MPDano]

Good job-that high temp is ******* the fluid, and ******* the clutches

Thanks for that. Piece of mind for sure. Will report back after cooler installed and new temps reported.

 

[MPDano]

Installed the cooler in the rain. Fun. Started her up to temp and could feel the new cooler getting warm, so got good flow. Had to make a few dremel cuts on the grill as to not rub the cooler or hoses. Anyways, will report back on temps.

 

[MPDano]

..more pics

 

[MrBalll]

Nice looking install. Hopefully that new cooler will help you out more when towing that hauler.