Transmission temp. Issues

[Cummins86dwr.]

I have a 07 5.9 Cummins and I'm having some temp issues with trans. When I'm doing normal highway driving trans. Temp will be around 170 to 180. When I'm in city traffic then temp will go up to 205 or some times a little higher. This is empty and not hauling anything. If im sitting in traffic and truck is in drive and not moving the temps will rise but if I put truck in park or neutral the temps will start to lower. If truck is moving a highway speed it doesn't seem to get that hot hauling camper only if I hit a good hill temp will go up. I have noticed as well if I'm trying to park the camper temps will go up as hight as 215 to to 219. I'm guessing from going to drive to reverse several times is causing that issue. Any help would be appreciated.

 

[Hoefler]

Normal

 

[sojoe]

I always go to N in traffic at long lights to keep things cooler

 

[DavidC]

Sounds Like my DTT in the 99. I to shift to neutral in traffic, I have 2nd gear lockup at approx. 18mph so I shift to second when in slow traffic. I haven't found a way around the backing up of the 5th wheel. The temps get downright scary.

 

[BigPapa]

Sounds normal. As mentioned, ALWAYS shift to neutral when stopped.

 

[Cummins86dwr.]

Ok today I was driving home empty and it's around 80 degrees and trans temp was running at 186 on back rounds going 50 mph. Hopefully it's not a big issue.

And thanks everyone for the info

 

[Jim W]

That's perfect temp reading, in my humble opinion!

 

[Cummins86dwr.]

Sounds Like my DTT in the 99. I to shift to neutral in traffic, I have 2nd gear lockup at approx. 18mph so I shift to second when in slow traffic. I haven't found a way around the backing up of the 5th wheel. The temps get downright scary.

Just curious what temps do you see backing in your 5th wheel?

 

[DavidC]

Just curious what temps do you see backing in your 5th wheel?

I have seen 230 before going to neutral and letting it cool down. I am sure if it was a better ratio and didn't have to work so hard it would be better.

 

[Cummins86dwr.]

I have seen 230 before going to neutral and letting it cool down. I am sure if it was a better ratio and didn't have to work so hard it would be better.

Ok thanks for the info. I have heard that synthetic trans fluid is good at 240. I should be fine then. Thanks again

 

[DavidC]

Ok thanks for the info. I have heard that synthetic trans fluid is good at 240. I should be fine then. Thanks again

I burnt my fluid going through a town in South Dakota with red lights every 2 blocks, when one turned green the next went red. That was with Valvoline ATF 4 which is synthetic. The trans could never get to lockup so it just churned itself to oblivion. This was all while towing.

 

[Cummins86dwr.]

That's no good what temp get to? Did u just change fluid and good to go?

 

[DavidC]

That's no good what temp get to? Did u just change fluid and good to go?

It was well over 210, I was very frustrated to say the least. Pulled the dip stick in Az. for the burnt smell test. Drained everything including the TC, 16 quarts, new filter. It's not only the fluid,clutches I worry about but the seals. Also adjusted the bands while I was there. Needless to say I am very cautious anymore with shifting to neutral, second gear lockup etc.

 

[Ozymandias]

The Gen3 have a better heat exchanger, they are fine in stop and go.
The only time mines getting hot is on very step mountain roads were it is only in First and second Gear without a chance to go into lock up.
Then i use Low Range and go up with the TC locked.

To back up a Fiver i would always use Low Range.
Your transmission isn't getting hot because of the shift F<>R, its because the reverse Gear is so tall on the 48RE that the TC has a very hard time to make the vehicle Move - Low Range, Problem solved.

 

[cerberusiam]

Operating range on a stock 48RE is 140-240 degrees, anything in that range should prove no problem if you follow fluid change rules.

If you are reading the temp electronically off the transducer in the pan subtract 20 degrees for actual temps, the pan temp sensors are notoriously for reading high and just generally being skewed.

If you see a temp rise under load when you hit a grade and it stays in OD you have a problems. Once the truck is OD with the TC locked and staying there you should see no appreciable temp rise. A temp rise in those conditions is an indication of something slipping, either TCC, direct, or forward clutch pack. Any one or more of those can be causing that.

 

[Cummins86dwr.]

Operating range on a stock 48RE is 140-240 degrees, anything in that range should prove no problem if you follow fluid change rules.

If you are reading the temp electronically off the transducer in the pan subtract 20 degrees for actual temps, the pan temp sensors are notoriously for reading high and just generally being skewed.

If you see a temp rise under load when you hit a grade and it stays in OD you have a problems. Once the truck is OD with the TC locked and staying there you should see no appreciable temp rise. A temp rise in those conditions is an indication of something slipping, either TCC, direct, or forward clutch pack. Any one or more of those can be causing that.

Ok good to know, I'm reading the temp off my bully dog tuner. If the temps get to high shouldn't a alarm go off on the dash?

 

[cerberusiam]

The ECM will trigger the dash alarm and drop it out of OD while going to aggressive lockup at a measured 260 degrees. On my truck I was seeing that happen around 240-245 observed temp on an analog gauge. It takes a good heavy load, lots of stop and go in high temps t get there but it can.

 

[Cummins86dwr.]

The ECM will trigger the dash alarm and drop it out of OD while going to aggressive lockup at a measured 260 degrees. On my truck I was seeing that happen around 240-245 observed temp on an analog gauge. It takes a good heavy load, lots of stop and go in high temps t get there but it can.

Ok thank you and everyone else for the info. I definitely feel a lot better now hauling my camper and anything else.

 

[cappetera]

I have a 07 5.9 Cummins and I'm having some temp issues with trans. When I'm doing normal highway driving trans. Temp will be around 170 to 180. When I'm in city traffic then temp will go up to 205 or some times a little higher. This is empty and not hauling anything. If im sitting in traffic and truck is in drive and not moving the temps will rise but if I put truck in park or neutral the temps will start to lower. If truck is moving a highway speed it doesn't seem to get that hot hauling camper only if I hit a good hill temp will go up. I have noticed as well if I'm trying to park the camper temps will go up as hight as 215 to to 219. I'm guessing from going to drive to reverse several times is causing that issue. Any help would be appreciated.

 

[cappetera]

I had that problem on my 2006 5.9 3500 - I had a bad fan clutch - I never had any codes either - put in a NAPA fan clutch and now when I idle the transmission cools down instead of heating up