Tranny temps?

Murphie · 10-25-2011, 11:00 PM

The new truck I have shows what the tranny temp is. I was just wondering for those of you who tow and are able to monitor your tranny temp, are the tranny temps higher when you tow in drive as opposed to towing in third? Furthuremore what difference is there in temps if your able to put your truck in " tow/haul mode". I know I could answer this given time but just wanted to see if there was a given norm for this and something I could verify.

robo59097 · 10-26-2011, 12:13 AM

We had this same discussion in the tow vehicle section. Check it out

http://www.jaycoowners.com/showthread.php?t=3999

Rustic Eagle · 10-26-2011, 12:43 PM

Richard,

With my TV/TT combination the outside weather temps and road environment influences my tranny temp. Higher outside temps and towing in the hills and/or mountains I could experience a little higher tranny temp (may push 200 degrees), but my engine temp always seems to remain stable.

I always tow with tow/haul "on", and it doesn't seem to have an impact on my tranny temp, on or off. Most of my towing is in 3rd at about 62mph, but I will tow in "D" if I'm on the flats without any major wind issues. Two advantages that I nave incurred when towing in "D" are about a 10 degree reduction in tranny temp (very notable on hot days), and a 500rpm engine reduction.

I would say that in most cases my transmission temp while towing seems to match my engine temp, about 185 degrees.

Bob

mcfarmall · 10-26-2011, 04:35 PM

What ever did we do before the transmission temperature guage???

**Crabman** · 10-26-2011, 05:50 PM

Quote:

Originally Posted by mcfarmall

What ever did we do before the transmission temperature guage???

Whatever we did, I`m still doing it. I`ve never had one in my life. That`s not to say one would not be nice to have though..................

clutch · 10-26-2011, 07:17 PM

Quote:

Originally Posted by mcfarmall

What ever did we do before the transmission temperature guage???

We overheated our transmission fluid and shortened the life of our transmissions.

Murphie · 10-27-2011, 12:21 AM

Thanks for the feedback, Bob it's kinda funny that your two reading are similar. I suppose mine will be too. In the past I've usually towed in drive with the tow/haul mode on. I always thought that going 60 mph in third would be overworking the motor.

Da Bud Man · 10-27-2011, 04:46 AM

Quote:

Originally Posted by Murphie

Thanks for the feedback, Bob it's kinda funny that your two reading are similar. I suppose mine will be too. In the past I've usually towed in drive with the tow/haul mode on. I always thought that going 60 mph in third would be overworking the motor.

Gas engines are designed to rev, thats where their HP and TQ numbers come in. You will not hurt that 6.0 running in 3rd at 60mph. I used to run that engine a few years ago in a 2500HD pulling a 10k fiver that we had at the time. I always towed in third with tow haul on. The only time i could tow in overdrive was if the terrain was extremely flat.

Now to your original question. I am running a Dodge 2500 auto w/the Cummins. I run in overdrive all the time. It takes a pretty good climb for mine to jump out of overdrive. I have several gauges that i monitor, including tranny temp. I installed my tranny temp probe in the hot line going to the cooler. Putting it there gives me a true reading of whats actually coming out of the tranny and it's hottest point. Probes in the tranny pan, which is where yours is if it's a factory gauge, will only give you an average of your temps. Not to say its not a good reading, just a different reading. Everybody has their own opinion of how to monitor things.

As was said before, outside temp and load on the truck will vary the readings, but i can usually count on my tranny temp running 100 degrees over ambient temp. If it's 85 degrees outside, my tranny will run somewhere between 175-190. It will also vary alot for in town driving when the torque converter is not locked up, thats where you can generate alot of heat in the tranny.

Rustic Eagle · 10-27-2011, 08:31 AM

Quote:

Originally Posted by Murphie

snip....... I always thought that going 60 mph in third would be overworking the motor.

Richard,

When I'm towing in 3rd at around 62mph, that's about 2,700rpm and the engine isn't really working hard at all. If I'm not mistaken, my '02' 6.0L gasser doesn't reach full horsepower and/or torque until 4,000rpm - 4,400rpm.

As mentioned, the GM Vortec gassers are high rpm engines so a little engine noise when it starts to actually work a little (hills/mountains, etc.) is a normal day doing what it's designed to do.

In another thread I noted that my 14,700lb TV/TT combination running down the highway at 62mph in 3rd is my "sweet spot" (60-65mph) under most road and weather conditions. I get my best gas mileage and still have plenty of pulling power should I need it.

If conditions allow me to tow in "D", I save a little on my fuel consumption.

Richard, if your TV/TT combination allows you to tow more often in "D" without the tranny hunting for gears, than that's ideal..., but then again, don't worry about towing in 3rd.

Bob

Murphie · 10-28-2011, 09:35 PM

Thanks guys. I just RTFM. It's over 600 pages

It actually confirms exactly what you guys were saying. When I was looking around on the Chevy forums there were several posts having opposing views and I just wanted to hear your opinions which I've come to trust.

Murphie · 11-02-2011, 03:01 AM

I pulled my trailer for the first time today with the new truck. I had to tow it over a high mountain pass and during the toughest part of the climb the tranny recorded a temp of 208F which was 99C when I switched it over. Most of the time in the mountains the tranny read about 180F. When I was past the summit the temps dropped to about 150 to 160F. I remember noticing temps in the low 60's C when I had it on the metric units. I drove mostly in third gear. Wow I just love this truck. I did about 9 hours of driving with half of that towing the trailer. I would have found that real tough in the old truck. The trailering suspension with the 6.0L motor makes for a great tow vehicle .

clutch · 11-02-2011, 10:25 PM

So another happy Chevrolet owner. My son tows with the same truck and it works well for him.

AMC_Jeep · 11-05-2011, 08:58 PM

I think most TV's can benefit from a larger ATF cooler.

You want the ATF around 180-195 MAX.

Spike99 · 11-05-2011, 09:54 PM

Quote:

Originally Posted by AMC_Jeep

I think most TV's can benefit from a larger ATF cooler. You want the ATF around 180-195 MAX.

Agree. My local transmisson specialist says GM transmissions tend to run hot. Good on flat ground but up hills against a strong heat wind, their temps climb (even when NOT towing / hauling anything). Thus, always go +1 size larger on GM vehicles. Works for me...

Good temp chart below...

re: http://www.txchange.com/heatchrt.htm

You may also like: