The other day I was just driving around when I noticed that my trans gauge read 210. I wasn’t hauling anything and I wasn’t roddin it. I ran 160 in the winter and when the temperature went up in the spring I noticed that I was running 175 and once I hit 190. It kinda worried me at first but now I’m really concerned because even when the temperature goes down into the seventies, spring temps, at night my trans stays at 200 idling and with any throttle it goes right back up to 210. I just had my trans flushed and both filters changed. Oh yeah, I have a 2002 ext cab short bed duramax with the five speed. I just put a new exhaust and a banks wastegate on in anticipation of a programmer but now I don’t know. I know that an aftermarket trans cooler would help but I think that there might be a serious problem causing the heat. What should I do?

I might try another spin on filter. Can't hurt to try.

Mine often runs at 220 but I am here in Phoenix where the ambient temps are often 110 in the summer. I told the Allison dealer this and they told me "That's not hot, that's completely normal." So I changed to synth fluid because I know it is mor thermally stable.

I agree with the suggestion to change the spin on filter. They do seem to be often restricting flow far earlier than the recommended change interval would indicate.

That's actually about normal for heavy stop and go traffic with the AC on ?

I thought about the filter thing earlier and had my tranny flushed and both filters changed this last thursday. DMAXITOL, at what outside temp is 210 trans temp normal? I ask because this is my first DMAX...

Thanks for your help guys
Nick

what did they replace the fluid with? dex III i assume?

150 is normal for me regardless of outside air, except i see maybe 20-30degrees hotter if in HOT (90+) stop and go traffic......

i don't know what mike says about fluid temps but 230 would make me a bit nervous (maybe just because it would be way out of the norm for me)

Had a similar thread going a while back. Now (with a new TC) I hardly ever hit 210.

230 sucks. If you see it, and you are outta warranty, back off the throttle, find a place to grab some chow, and shut her down...

240-ish and the truck starts protesting - christmas bells and warnings on the DIC...

I thought about the filter thing earlier and had my tranny flushed and both filters changed this last thursday. DMAXITOL, at what outside temp is 210 trans temp normal? I ask because this is my first DMAX...

Thanks for your help guys
Nick

Hmmmm, what brand of filter did they use? If it was anything other than a GM or Ally I would change it. Might be a cheap P.O.S.

I don't know what filter they used but i had the service done at a dealer so i assume that it was replaced with a stock one.

I changed my filter out and saw a slight drop in temps but did notice that the high temps were less frequent.
My filter had 5k on it and it was the factory Alli. filter.
I ordered a tranny cooler from MikeL I will let ya'all know how it works. From what I have read (and been told) I whould see a 20 to 30 degree drop in temps.

Yeah my filter has like 150 miles on it so i don't think its that. Ive heard that the Mike L cooler is the way to go I've jus tgot to decide what i'm goin to do.

Except for my fluid turning dark prematurely, my trans has been acting fine, except.....it normally runs 150-160deg unloaded. Pulled the boat for the first time w/ it this weekend. Running in 90 deg air temps, 4,000lb trailer, 80mph on the freeway, some grades, some flat, the trans sat at 200deg, even on long downhill runs.
Is this normal?
I expected it would run a little warmer, but given it can tow 15-20k lbs, didn't expect to see those temps w/ my little trailer.

I've asked around on here and i have contacted a couple of local dealers, they all say its pretty normal. I'm runnin up to 210 unloaded with the ac on. I hit the 210 mark right after i installed my new wastegate. I was really on it trying to see if i could feel a difference. I've slowed down now and I haven't hit 200 since. I run about 180 now. Oh yeah, outside temps are around 90-95 w/ stop and go traffic along with 75-80mph on the freeway.

i know when i changed mine on my 4500 the other day i used a napa filter and the magnet blocked the holes in the actual filter so i left it out.

i know when i changed mine on my 4500 the other day i used a napa filter and the magnet blocked the holes in the actual filter so i left it out.
Read here that enuff oil still flows around a Napa filter. Had one on my truck, only a short time though, 'cause I flushed the trans shortly after changingthe filter. No issues.

I have a napa filter now and i have hit temps above 200 sitting in trafic and probbly about 220 in LONG stop and go traffic, but when im on the highway crusing at 70-75 mph its around 150- 170. not sure what the deal is.
the trany was flushed only a 1000 miles ago or so and the spin on tranny filter is not that old.
Im guna switch back to an Allison filter and see what hapens.
but anyone have any input????

I'm in Phoenix, AZ and my tranny temp stays 150-170 with the AC on and no load. Foot gets heavy and it gets up 190ish.

I have a napa filter now and i have hit temps above 200 sitting in trafic and probbly about 220 in LONG stop and go traffic, but when im on the highway crusing at 70-75 mph its around 150- 170. not sure what the deal is.
the trany was flushed only a 1000 miles ago or so and the spin on tranny filter is not that old.
Im guna switch back to an Allison filter and see what hapens.
but anyone have any input????

When your in "LONG stop and go traffic" there slippage in the torque convertor that's generating heat, so you would expect to see higher temps. Once at speed the Torque Convertor is locked up so there's no slippage and less heat built up plus a butt load more air is moving across the cooler.

DEWFPO

Yeah my filter has like 150 miles on it so i don't think its that. Ive heard that the Mike L cooler is the way to go I've jus tgot to decide what i'm goin to do.

I had Mike L install his tranny cooler on my truck when he first came out with it. It really works! With the Lance camper and boat it weighs 17,000lb. I just came back from the Colorado River on Int 40. Outside of Needles, Ca heading to LA there is a grade about 20 miles long. It was 107 degrees outside. When I crested the tranny temp was one mark shy of 200, enginge temp 228. I shut the air off around 3/4 of the way up. I have many long trips with this setup and it never goes above that mark. I consider it money well spent:exactly: