Transmission Temperature and Scangauge

[Captain Morgan]

Well, I finally programmed my Scangauge II so it reads the transmission temperature on my Workhorse W-22. It seems I always think about this as I’m driving down the road and then conveniently forget about it until I’m on the road again. Although I love the way my rig handles, it’s a little too much to try and program the Scanguage while driving down the road. Anyway, I finally programmed it while we spent the week at Stone Mountain Park in GA. I watched the gauge closely on our way home last Sunday and, once warmed up, held a fairly consistent reading between 154 and 156. It did hit 158 a couple of times climbing a few of the minor hills and 162 when sitting at a stop light. The outside temp was around 94 degrees and was towing the Vue.
I’ve always had water temperature gauges, but never a transmission gauge. So here’s the question; what should it read and at what temperature should I be concerned.

Thanks in advance,
Bob

[blacktie.shooter]

Quote:

Originally Posted by Captain Morgan . . . I’ve always had water temperature gauges, but never a transmission gauge. So here’s the question; what should it read and at what temperature should I be concerned. Thanks in advance, Bob

Bob, I just installed a tranny temp gauge, because, I assume like you, I was concerned about how high my tranny was heating up when pulling a toad up a steep grade, etc.

Everything I have read and found on numerous websites tell me that if your tranny gets to maybe 230 or 250 for any period of time, e.g., ten minutes or more, you are heading for trouble. The number one tranny killer is heat - read, overheating. For that reason, I switched my old Ford C6 to Mobil 1 synthetic.

I can tell you that when I pulled a familiar grade with dino oil, my engine temp gauge went up about 40+ degrees. Pulling the same grade with Mobil 1 in the engine got about a four or five degree increase. I immediately changed the tranny upon arriving home. I have since made two trips to AZ from WA, fully loaded, dragging a toad, no issues so far. (Please note, I do NOT lug; I shift down, keep the revs up, circulate lubricants, coolants, etc.)

I'm not an expert by any means, but sure sounds to me like you're staying in the safe zone. Good on ya.

[Captain Morgan]

Thanks Ken. I run Mobile 1 in the engine since I bought the rig 3 years ago. It had a little over 9,000 miles on it and now has over 21,000 on it. I’ve never had a problem with the engine heating up. I too believe in keeping the revs up so I’m not ‘lugging’ everything up the hills. Last year we took a trip out West and the only problem I had was with fuel cavitation/vapor lock when climbing some of the real mountains while the temperature was over 100 degrees. As I haven’t had a gauge to monitor the transmission, I don’t have any history to determine how well it handles long steep grades while pulling in hot weather. Most of our travels will be up and down the East coast until next summer when we head out West again. It’ll be interesting to see how high the temp gets now that I can monitor it.

[angelman]

My brother-in-laws 2004 yukon XL 2500 has a factory installed trans temp in the dash cluster. When driving in traffic it climbs to 200. when towing a triple (11,700lb) axle race trailer, it reads between 155 and 170 with nominal hills. He also has the 8.1L Vortec. You can use these figures as a reference point.

[dieselclacker]

Bob, my 2003 W-22 trans temp runs between 150 - 170 towing my Suzuki. Just last week pulled a 6% grade about 6 miles long in Idaho with outside temp 85 degrees trans temp never got over 170. Good rule of thumb for trans temp is not to let it get any warmer than engine coolant temp. It will normally be 20 to 30 degrees cooler than engine temp the way the trans cooling package is installed in your Workhorse.

Dieselclacker

[Captain Morgan]

Thanks everyone for the responses. These figures are pretty much in line with what I thought they would be. I certainly feel more comfortable now that I can monitor the Transmission temperature. I can't wait for our next trip just so I can watch it flucuate under different driving conditions. Well, at least I'll use that as a excuse to take another trip!

Thanks again!