Drivetrain Operating Temperatures

[DEVO]

After a 35 mile trip home the other day at 45 mph average (last 9 miles at 50-55mph), I got the infrared thermometer out and read temps on a few things.
Ambient temps were 50°F-60°F.

Here's what I found:
Hubs: 95°F - 110°F
Diffs: 110°F
T Case: 186°F

What the heck is with the T-Case temp???? Is that normal? I had changed the fluid a day before, correct type and level....

Do the hub and diff temps sound typical?

This was in my '66 M35A2, btw.

 

[dk8019]

I need to IR mine sometime, I know my diffs and hubs are warm to the touch, not on fire, but I think around 130F, which is one of the reasons they are getting greased this coming week. The T-case I've never felt though, but I bet it does get warm!

 

[Speddmon]

my hubs were about 120 to 140 after about 2 1/2 to 3 hours of hard driving back from WI. I didn't think to check the diff's, tranny and transfer. As long as they all have good oil and the proper level, that's probably not bad though.

 

[bigelk50]

I have an IR gun I have checked things on the engine before, but checking the drive train is a good idea!!

 

[2Deuces wild]

Check oil level in transfer case. If low add until second knuckle don't over fill. If really nasty dirty drain flush with dextron 3 and replace with new oil.

 

[badgmc56]

One thing you have to remember. The gear ratio's of these trucks makes everything spin faster than a normal vehicle. Hence more heat. A bad bearing in any componant will make it run warmer than normal. You have to figure out what is normal first before you start to get worried. These trucks were not built to cruise down the hiway at top speed for hours at a time. I even read somewhere you have to give the tires a cool down period after a certain amout of driving. The same should apply for the drivetrain.

 

[bgekky3]

My hubs would get hot quick. If I drove 10 miles or 50 miles they were all about the same except for one. The left, front, rear ran 113 to 118 and the others were 98 to 105. I played with bearings, seals, and grease, but one always ran hotter than the others. Someone before mentioned a possible bent spindle. I drove it home about 50 miles after working on it. I had a bearing a bit tight and it was 130 or 140, I can't remember to be sure, but it was really hot, smoking when I got home. I readjusted the bearing and have had no problems since. Ambient was 70 to 80.

 

[Barrman]

Figure 230-250 as the max heat for mineral based oils. With that in mind along with the mention above about how because of the gearing things spin pretty fast. 186 isn't really all that bad. My M715 t-case was at 230 after I flat towed the thing behind the Whistler 90 miles a month ago. I have to make a oil recovery trip tonight with the Whistler in our lovely 106 or so outside temp. I will try and get a t-case reading after 30 miles of so and post what it is.

 

[Green_gator]

I need to get a good set of "normal" temperature readings on mine for both summer and winter and day versus night. I know that it makes a major difference on temperatures for me if I drive at night versus the day time during the summer. I have given in and gone for warehouse space to store my two deuces just so that I can work on them in the summer. Has anyone done a set of measurements for temps looking at exterior temperature and the effect?

 

[OPCOM]

My hubs would get hot quick. If I drove 10 miles or 50 miles they were all about the same except for one. The left, front, rear ran 113 to 118 and the others were 98 to 105. I played with bearings, seals, and grease, but one always ran hotter than the others. Someone before mentioned a possible bent spindle. I drove it home about 50 miles after working on it. I had a bearing a bit tight and it was 130 or 140, I can't remember to be sure, but it was really hot, smoking when I got home. I readjusted the bearing and have had no problems since. Ambient was 70 to 80.

check the brake drag on that wheel.? It was the result in my case. Only a small drag will raise the temp.


as fot t-case and transmission temps, they have always been too hot to touch after highway driving. 20,000 miles later I've seen it as normal.

 

[Barrman]

I forgot! Sorry about that. I was going to pick up a drum of used oil, got there, went to work, got to talking and went home.

 

[bgekky3]

The brakes were adjusted to spec and the bearings were changed. It was still the same. It isn't too bad. When it got hot it was a too tight bearing. I re-adjusted it and did nothing to the brakes. I was going to swap the whole hub to the other side, but after a 650 mile day, it was still just a little hotter than the others. I usually check the temp after I run it. As long as it doesn't get worse it should be fine. I guess that is the character of an old truck.

 

[dk8019]

I was checking my fluids in the tranny, transfer case, and axles. Everything was where it belonged and looked good. I have to say that working under a truck that you can sit up underneath of is awesome.