Engine/Transmission (1998.5 - 2002) Hottest 6 speed temp??

[Turboman]

What is the highest temp seen on a 6 speed? I get shy at 225*. Maybe I'm to cautious. What is normal w/ no load, what do you see with big load? thanks

 

[KcoleKennyc]

Mine will run up to 250 on a hot day with a heavy load. Usually runs under 200 empty. Drivers of the big rigs say their gauges show red at 300. I would still like to have a pump and external cooler for those hot days.

 

[PBayer]

I just drove from Maryland to Florida. GCWR 20000 lbs. Maintained 72 78 mph, trans temp was around 210 to 230. Trans felt fine. Using Red Line MTL.

 

[Texas Diesel]

180F empty, highest 230F, 99F mountains towing trailer. I have one FastCooler and PTO filter and Royal Purple Synchromax. I believe temp probe placement will effect temp seen.

 

[Turboman]

I've been told that under 300* is OK. Sounds a little high to me, but I'm no expert. My temp sender is in the top of the left fastcooler, with a filter on the right side. I am experimenting with Amsoil 30w Powershift Trans Fluid and it seems to be working as good as what you guys are running, shifts fine hot or cold. I may try the 50w version next, these are the same oils we use in our big truck trannies.

I have found a 12 volt pump that will work for this, but I'm trying to decide if I tow enough to be worth it. Although a pump and cooler would make it easy to add a spin on filter too.

So 230* is the hottest so far, do I hear 250*?

 

[Mad Bomber]

what's hot

Originally posted by PBayer

I just drove from Maryland to Florida. GCWR 20000 lbs. Maintained 72 78 mph, trans temp was around 210 to 230. Trans felt fine. Using Red Line MTL.

That's where I'm at too on temp going from ocean to home. It was 90 + that day

 

[CFAR]

I've hit 230*. 10K going over the continental divide @ about 75mph. Speed and weight seem to be the deciding factors. At 65 I don't see anything over 200*. I have both fast coolers attached. Penzoil syncromesh

 

[Gary - K7GLD]

Dunno about transmission lubes, but seems most engine lubes have a flash point up over 400 degrees - so 200+ on transmission lube might not be too bad - and I suspect that since the whole transmission case is a big heat sink, temp probe placement probably is not very critical for average readings...

 

[Diesel Gunner]

Interesting.



I have my temp probe on the top right side Fast Cooler. I noticed that the trans temp will climb 25 to 50 degrees when coming off of the highway and beginning to use low gears. I suspect that first and second gear sling more of that hot lube on that improperly positioned temp probe causing the temp swing. Really thought that I ought to turn the fast cooler around and get that temp probe down into the lube to get a more accurate reading.



I will do this on my next trans service. Seem to me that if I want to know what the temp of the trans fluid the probe should be in the fluid. I noticed that the coolant temp probe is not in the top of the overflow tank. Those engineer guys are so smart! But, I bet that they don't drink beer when they are doing things to these trucks, like I do. That's why my fast cooler is upside down.

 

[Mad Bomber]

prob

I also have the Fast Coolers and the prob is in the bottom and still see the 200 to 230*