Engine/Transmission (1998.5 - 2002) Transmission Temperture

[JTBMC]

I just spent a week in the Smokey Mountains and got my ATS Auto trans up to 200 degrees in the pan pulling some long grades, at 15 to 30 MPH & below due to the steepness of the grade and trail conditions. I was also in 2 wheel high due to the hard surfaced trail. The temps were only at 200 degrees for about 10 minutes and then came back down to about 145-150 area.

I am running Amsoil trans fluid with about 3000 miles on it sense the oil change.

I forgot to adjust the bands when I did the last oil & filter change could that be the reason for the high temps as Ive never been over 160 degrees on the same road w/same load of camping gear in the bed before. ( I was not pulling my trailer at the time. )

What temps should I be seeing and are safe.

Thanks, TJ

 

[rrausch]

I don't believe 200 degress for 10 minutes is going to hurt your transmission.

Before I got my ATS, I saw higher temps on grades pulling loads. The ATS will run cooler than other Performance Trans systems which depend on Fluid Coupling instead of a strong lock-up clutch. But call Clint if you think you have a problem, somebody there will be happy to answer your question. 800-949-6002

 

[RowJ]

High Temps on transmission Fluid

Don't know why you got higher temps than previously, but I do know 200 degrees on a good synthetic ATF, like the one you are using, won't hurt a thing. You could run that fluid at 250 degrees for 2-3 hours (some racers do) and it would give excellent protection and return to like new condition when it cooled down.

Frequent running over 200 degrees+/- will shorten fluid life by 50%, but wont damage anything.

 

[JTBMC]

Thanks Guys,

My Trans seems fine, no slipping or shudder, the oil is just as pink as new oil and smells fine too. I was just concerned that I may have self inflected a problem by forgetting to adjust the bands at the oil change. Trans has 30,000 miles now with out a band adjustment. It was getting ready to come a storm and I got into a hurry to beat the rain and beat it for sure, it never came till the next morning.

Thanks again, TJ

 

[RWatson]

200 degrees for a brief period should not cause any harm to the trans, but may shorten the life of the fliud a little.



Something I recently discovered in fighting a transmission temperature problem of my own... ... . 280 degress and higher , is there are two one way valves inline that can get clogged and during a load or when convertor is not locked out, can cause fluid flow issues.



One good thing did come out of my transmission temp problem... . the wife has approved a DTT transmission makeover



Randy

 

[rweis]

2 one way check valves?



I thought there was only 1 at the water heat exchanger.



Bob Weis

 

[RWatson]

I have been battling a transmission temperature issue for well over a year now and it was not until recent that I discovered the valve and was told that since I added the OEM output line for my temp sensor that there was an additional valve assosciated here... have not confirmed this though.



I have not yet pulled any of these to see if this fixes my issue but rather I have finnaly decided to do what I should have done over a year ago... . have a real transmission tech due what is needed... a full DTT trans makeover.



The one thing that has amazed me is that I have had the truck into two seperate shops for this issue multiple times over the last 16 months, including having the transmission pulled and so called rebuilt, yet the local shops did not know anything about the valve or what is was used for.



Pretty poor when we have to both pay them and tell them what the problems are and how to fix it



Randy

 

[rweis]

Ahhh, I see why two now.



The one that came in the 1995 line was suppose to be taken off. There is a stainless steel replacement for the rubber line from DTT just so the length is correct and the one too many check valve is not an issue.



Now, that said. You can go to the DTT web site and read threads about taking out the one way check valve in the water heat exchanger. There are pros and cons. If you do a search on it here on TDR I know you will find the threads as well.



I took the check valve out, but know that there is drain back to the T/C and give the lube circuit 30 seconds or so to be sure it is charged before selecting a gear. I have a DTT and have lube circuit in park that the OEM DOES NOT have. While still OEM, only neutral has the non gear selected lube circuit running. So before DTT you need to choose neutral for 30 seconds for the lube circuit to charge IF you take the (last) check valve out.



I took mine out to reduce the potential failure point, and to not restrict the fluid flow. I asked BK if he did it on all rebuilds and he said "no, depends on the drivers". So it is not a cut and dried thing, has tradeoffs.



Hope this helps,



Bob Weis

 

[MCummings]

260*+ in the pan here. When I drained the fluid later, it poured out red from the drain plug in the pan, but when I looked into the bucket, it was burnt black, with only a hint of red.



Funny thing was,, I didn't see 260*+ when running the truck hard. I ran the truck very hard for 15-20 seconds then popped the truck in neutral, and watched the temp climb from 180* to 260* within the next minute.



Merrick Cummings Jr