Normal Transmission Temp?

[VWhidden]

I have a 2015 RAM 2500 Laramie diesel/six speed automatic transmission with 5K miles on it. The transmission temp seems to run at around 237 degrees when I'm not towing and the outside temp is around 50 degrees. The middle of the temperature guage (computer generated graphic) is around 145 degrees, so it doesn't make sense to me that 235-240 would be normal. Had it into the shop and they said the fan clutch was seized up (5K miles) and replaced it. Is 235-240 "normal"? Is there any hardware like a thermostat that could be frozen closed? Thanks in advance for any info.

 

[woody72]

Mine runs around 200-215 degrees.

 

[jacknife]

Normal temp when not towing should be around 170 deg F . Your readout must be screwed up. have dealer reflash gauges see if that helps. that reading is way too high

 

[transe]

Yes, 235-240°F sump temp in 50°F ambients, when not towing, is way too hot. Dealer needs to do some further diagnostics.

One possible problem is the Thermal Bypass Valve (TBV), which is an H-shaped block of aluminum in the middle of the cooler lines. It bypasses the cooler (circulates warm fluid right back to the trans) as it is warming up (to hasten the warmup), but then once sump temp is 170-180°F it should open and allow full flow to the cooler. Warm up the truck, then check the temp of the return-side lines. The return line to the trans is the BOTTOM line on the transmission. Follow that line back to the TBV. The line opposite that line will be the cooler return line (from cooler to TBV). If the TBV is fully open, the temp of both these lines should be basically equal. If the cooler return line is cold (compared to the return line to the trans), and the sump temp is 200°F or more, then the TBV is not opening properly. If BOTH of the return lines are cool, then maybe your cooler is plugged (and you are getting little or no flow).

 

[DANV]

170* for me

I have yet to see mine jump above 170*F. Usually runs around 160 after 20 minutes of driving. Mine is a daily driver. Don't tow much.

 

[Dieselnerd]

Mine runs around 170, slightly higher when towing heavy. I never saw it go above 190 even on the steepest grades towing in hot weather.

 

[Bug Out]

All three of the 68 RFE's I have owned(2012,2013,2013) in the last 4 years have run 160-180 when NOT towing. Your about 50 degree's too hot..

 

[RustyJC]

Not that it matters or has anything to do with the OP's situation, but my junky old 68RFE (according to some on this forum) was running 143 degF this past Sunday towing our 19K GVWR 5th wheel at 65 MPH on I-45 in 50 degF ambients. Even in 100 degF weather, it runs about 170-180 degF at steady 65 MPH speeds on level stretches when towing.

Rusty

 

[VWhidden]

Thanks everyone. I really did not believe 235ish was normal, but with your help, I now know what is normal. Back to the dealership it goes. I even sent them TransEngineer's information so they know what to do. The service adviser at the dealership is a nice lady but I really don't think she knows anything about vehicles. I just wish she wouldn't have tried to BS me if she didn't know what she was talking about. Thanks to all. This is a great forum!

 

[TJJEEPER]

Most of the time Service Writers are salesman and not anywhere close to being a mechanic. My niece's exhusband was one and his bonus was related to his "upsales" and not necessarily customer satisfaction.

 

[Cummins12V98]

On my 11 with 68RFE the ONLY time it saw over 200 was stop and go on HWY111 Palm Springs area, hit the freeway and dropped to well under 200.

Typical towing temps were 160-175 in 75 to 100 degree weather.

 

[Hollnagel]

My trans temperature usually runs 70-80 higher than the ambient temperature.