I'm trying to find out the running temps of the rear differential on a 3500 diesel, with 410's & single axle with auto trans. I pull a 33ft. 5th wheel with 3 slides. Would appreciate any info, either way - while towing or not towing. Also I live in the west so lots of mountain towing.... I've got the trans. temp/numbers so am good on that...... thanks

 

its been a really long time but i think 180 is getting really hot but i could be wrong

 

Mine will run 180 with an empty truck. Gross up to 33K and have seen 225 to 250 on hot days. Have had no problems at all and don't think this will hurt anything.

 

I installed a Mag-Hytec cover on my 03HO this summer along with a thermocouple. It's the largest one... 8 quarts. Ambient temps were anywhere from 90-100 degrees this past July. I scaled out at 27,800 heading east on I94,I80,I90. Diff temps ran anywhere from 150 on a flat to 180 on grades. Never ran over 180. Evenings the diff temp would drop to around 100.

I'd reccommend getting a larger capacity diff cover. I used to work at DCX within truck chassis. Last summer I called up my good friend who works within the vehicle development group and asked what he reccommended given the weight I was pulling. He said hands down, a larger diff cover to increase the oil capacity to keep it cool. Other than that, it'll be fine.

 

Use a -140 gear oil when pulling it that hard. I use Amsoil.

 

Chrysler Transport driver here...are we going to have a job??? Ha!

 

I ran TCs into the cab and plug them into my Fluke 52. I only checked a couple of towing trips and I think the diff got a little over 220 pulling hard - no big deal. I had a D80 that ran well over 280 and was showing wear in the UOAs till I replaced all the brgs and set it up right but still ran ~ 245. That D80 is what made me go to syn RP 85w140 and it does the best on the UOAs and wearmetal on the magnet of any of the lubes. Craig

 

Thanks everyone for the info on temps for the rear diff. Answered all my questions.....Ray