What is the Normal Trans & Oil temp when just running normal on a 1500 5.7 Laramie?

What is the Maximum / Critical temps? (When should I start getting worried?)


In the temp gauges, there is a line in the middle, is this just to mark out the line, or to mark out a critical temp?


/Jocce

 

I don't spend a lot of time watching the temps, but I think that the oil temp is usually within a few degrees of water temp (193*??). Transmission can vary greatly depending on load and towing. I think it is often at/under 150*, but I have had it run to 220* on long pulls in the mountains with a big trailer behind (8500#). See the following thread for more comments on transmission temps:

Transmission Temps/Towing Questions

Rob

 

Check this link out. I think it says pretty much the same thing as the previous post.

 

Here's a review I posted a while back about towing through the mountains that has some additional details on temps:

Review of towing experience

Rob

 

The reason for asking is that when I was out playing in the snow, drifting and playing, for a couple of hours yesterday, I saw the temps go up a little, and was just woundering what is considered normal, and / or bad?


/Jocce

 

I guess ideal is below 175 degrees (F). Start getting above 200 degrees (F), and you'll need to replace the transmission fluid a little sooner.

 

The line in the middle merely represents the mid-point between low and high temperatures. That's all.

From my experience the coolant temperature reaches 195-200 degrees in summer depending on driving, and 185-190 in winter.

The oil temperatures rise always lags behind the coolant temperature and will usually come within 20 degrees or so of the coolant temperature. This is dependent on how long you drive. In the winter the oil takes longer to get to temperature.

The transmission temperature rise is even slower still, but very dependent on driving. I posted this in another thread, but I'll repeat here. 80 to 240 degrees F is normal operating temperature for 545/645RFE. You might find this useful:

545RFE Transmission Operation
The Transmission Control Module (TCM) is programmed to allow a select variety of shift schedules that are dependent on the following physical conditions:
· Selected gear range
· Throttle position
· Engine load
· Transmission fluid temperature
· TCM software level
The TCM will adjust the shift schedule of the transmission as environmental and driving conditions change.
-16°F and below and with the transmission in the Drive position, the shift sequence will be 1st to 3rd until the ATF temperature reaches -12°F. When placing the gear selector in either 1st or 2nd gear the transmission will be on 2nd gear only. There will be no torque converter lock up and switching off Overdrive will have no effect.
-12°F and -10°F the transmission shift sequences are as follows:
· No torque converter lock up
· No shift in to 5th gear
· Delayed 2-3 upshifts
· Delayed 3-4 upshifts
· High speed 4-2, 3-2, or 2-1 kickdown shifts are prevented
· High throttle opening shifts will be early
· Switching off Overdrive will prevent shifts into 4th gear
-10°F and 36°F the transmission shift sequences are the same as above, except that 2-3 upshifts are not delayed. Switching off Overdrive will prevent shifts into 4th gear
40°F and 80°F All shift sequences are normal except there will be no torque converter lockup. Switching off Overdrive will prevent shifts into 5th gear.
80°F and 240°F This is normal operating fluid temperature. The 545RFE will be in the normal shift sequence, including allowing torque converter lockup.
240°F ATF or the engine coolant 244° F, the transmission shift sequences will be as follows:
· delayed 2-3 upshift
· delayed 3-4 upshift
· 3rd gear FEMCC from 30-40 MPH
· 3rd gear PEMCC above 35 MPH
· Above 25 MPH the torque converter will not unlock unless the throttle is closed or if a wide open throttle, 2nd gear PEMCC to 1 kickdown is made.

EMCC = Electronically Modulated Converter Clutch

NO EMCC = No Electronically Modulated Converter Clutch
PEMCC = Partially Electronically Modulated Converter Clutch
FEMCC = Full Electronically Modulated Converter Clutch
Gradual to No EMCC = Gradual to No Electronically Modulated Converter Clutch

Regards,
Dusty
2010 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 545RFE, 3.92 LSD, dual exhaust, 20” wheels