Differential Heat

imonfire · May 10, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

Thanks

100R1 · May 10, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

Thanks

<{POST_SNAPBACK}>

Yes on the more frequent oil change

Larger capacity of oil is a good idea, get a finned aluminum cover even better

monitor the actual temperature is excellent.

Some aftermarket covers offer a port to add a temperature sensor.

If you have cooked the paint off the cover, it really got overheated. I'm surprised you did not smell it.

Are you pulling that trailer in the mountains or at Higher than posted speed limits ? Those are killers of excessive heat.

maybe you need 4:10 gears.

imonfire · May 11, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

Thanks

<{POST_SNAPBACK}>

Yes on the more frequent oil change

Larger capacity of oil is a good idea, get a finned aluminum cover even better

monitor the actual temperature is excellent.

Some aftermarket covers offer a port to add a temperature sensor.

If you have cooked the paint off the cover, it really got overheated. I'm surprised you did not smell it.

Are you pulling that trailer in the mountains or at Higher than posted speed limits ? Those are killers of excessive heat.

maybe you need 4:10 gears.

<{POST_SNAPBACK}>

I think I might change oil again when towing mileage gets to 1000 or so, is that often enough? I will be getting an aluminum finned cover soon. But until then I will monitor the heat levels and have something to compare, a before and after so to speak.

I do tow up mountains but not all the time, and I do not drive excessive speeds, normally I drive about 60 on flat areas and of course slower on mountains.

I like the 3.73 gears my towing mileage is about 11mpg which is better than most, my last truck got 9 mpg. You think 4.10s would make it run cooler?

It never has smelled like it was hot, I do check things regulary (over, under and around) while towing and have not noticed any unusual smells or indications. I got the idea to check it from this forum when someone suggested towing wreaked havoc on differentials. CHecked mine an wow, glad I did!! Does anyone else notice this when towing?

pm26 · May 11, 2006

I mentioned earlier that early ('04) Nissan Titan trucks had quite a few differential failures due to overheating when towing. Now they are equipped with factory installed finned aluminum differential cover. Not only do fins help dissipate heat, but aluminum dissipates heat at three times the rate of steel. (Your factory differential cover is stamped steel w/o cooling fins). Mag-Hytec makes nice finned aluminum differential covers, which come with an oil dipstick and a temperature sender port.

And another thing: using higher viscosity differential oil, such as 75W140 helps when towing under hot ambient conditions.

imonfire · May 11, 2006

I mentioned earlier that early ('04) Nissan Titan trucks had quite a few differential failures due to overheating when towing. Now they are equipped with factory installed finned aluminum differential cover. Not only do fins help dissipate heat, but aluminum dissipates heat at three times the rate of steel. (Your factory differential cover is stamped steel w/o cooling fins). Mag-Hytec makes nice finned aluminum differential covers, which come with an oil dipstick and a temperature sender port.

And another thing: using higher viscosity differential oil, such as 75W140 helps when towing under hot ambient conditions.

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Thanks I am gonna get me an aluminum cover with a larger oil capacity and maybe run some 75-140. I have also been looking at a product called PML, anybody ever used it and would they recommend it? Web site http://www.yourcovers.com/dc_9504.shtml

I will keep everybody updated on how well it works.

Rick

Mr. Smith · May 11, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

Thanks

<{POST_SNAPBACK}>

IF the oil isn't burned and stink to high heaven it is doubtful that the rear gears got that hot. Also was there blueing on any of the internals? My guess it typical of factory the paint pealed and the weather got to it and not the temperature of the fluid. Now it could happen but not likely as you said nothing is damaged.

imonfire · May 11, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

Thanks

<{POST_SNAPBACK}>

IF the oil isn't burned and stink to high heaven it is doubtful that the rear gears got that hot. Also was there blueing on any of the internals? My guess it typical of factory the paint pealed and the weather got to it and not the temperature of the fluid. Now it could happen but not likely as you said nothing is damaged.

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Internals looked good, didn't see any blue areas. Its just strange how the paint only peeled where the cover is expanded to go over the ring gear. Maybe I am just paranoid but I would rather be safe than sorry. Gear oil always stinks to me, but it didnt smell any different (high heaven) smell than usual. You would think that there would be bluing on the cover internally if it got hot enough to burn the paint. I didnt think of that

ChevyTech007 · May 12, 2006

All good ideas above. Might also want to consider synthetic lube.

imonfire · May 12, 2006

All good ideas above. Might also want to consider synthetic lube.

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Yes, it came with synthetic in it. It was even on the window sticker. I got some more from the dealer when I changed it the other day. I will get a pic of the rear cover in here this weekend and see if anybody else thinks this was a way too hot situation or I am just being paranoid. I was thinking maybe Amsoil severe gear fluid next time. The manual calls for 75W-90, will it be okay to run 75w-140 without causing problems or voiding the warranty?

100R1 · May 12, 2006

All good ideas above. Might also want to consider synthetic lube.

<{POST_SNAPBACK}>

Yes, it came with synthetic in it. It was even on the window sticker. I got some more from the dealer when I changed it the other day. I will get a pic of the rear cover in here this weekend and see if anybody else thinks this was a way too hot situation or I am just being paranoid. I was thinking maybe Amsoil severe gear fluid next time. The manual calls for 75W-90, will it be okay to run 75w-140 without causing problems or voiding the warranty?

<{POST_SNAPBACK}>

Stick with the factory recomended gear weight.

I researched it and there are many negatives against the heavier weight. due to the cloose tollerances in the GM axles.

Do you have the Eaton Locker ? another reason to stay with the factory fill recomendation on weight.

I'm use to Dana axles and having to run 90 - 140w synthetic, when I got the Yukon and the factory fill called for the 75-90w and the fact I tow a travel trailer I was sitting on the fence about "thicker is better" train of thought. Then I did some research.

I run redline synthetic 75-95w and have no problems or over heating even towing .

The grape juice from the dealer is fine except expensive.

imonfire · May 12, 2006

All good ideas above. Might also want to consider synthetic lube.

<{POST_SNAPBACK}>

Yes, it came with synthetic in it. It was even on the window sticker. I got some more from the dealer when I changed it the other day. I will get a pic of the rear cover in here this weekend and see if anybody else thinks this was a way too hot situation or I am just being paranoid. I was thinking maybe Amsoil severe gear fluid next time. The manual calls for 75W-90, will it be okay to run 75w-140 without causing problems or voiding the warranty?

<{POST_SNAPBACK}>

Stick with the factory recomended gear weight.

I researched it and there are many negatives against the heavier weight. due to the cloose tollerances in the GM axles.

Do you have the Eaton Locker ? another reason to stay with the factory fill recomendation on weight.

I'm use to Dana axles and having to run 90 - 140w synthetic, when I got the Yukon and the factory fill called for the 75-90w and the fact I tow a travel trailer I was sitting on the fence about "thicker is better" train of thought. Then I did some research.

I run redline synthetic 75-95w and have no problems or over heating even towing .

The grape juice from the dealer is fine except expensive.

<{POST_SNAPBACK}>

It does have a limited slip, but I dont know what brand, thats why I stayed with factory fill, I assumed it already has the friction modifier in it. I too was on the fence on the "thicker is better" train of thought, thanks for the info now I can get off the fence (hurts) .

mmmikkke · May 13, 2006

I have a 2005 1500 HD with a 3.73 gears and a 6.0 engine . If occasionally pull a 7000 lb trailer. I currently have 12,000 miles on the truck and have probably pull the trailer about 2500 of those miles. I noticed the rear end cover paint was coming off and rusted. I decided to change the rear end oil and check the gears because it looked like they were hot at one time . When I drained the oil it smelled just like gear oil but it was pretty black. Not much metal on the magnet. Gears looked fine . My question is, should I change the fluid more often because of towing? Should I look at getting a cover that will hold more oil? I was thinking of getting a non-contact thermometer and checking the temp on a regular basis, is there any value in this?

<{POST_SNAPBACK}>

I think your paint is peeling off for some other reason. You know Dana filed for chapter 11 a few months ago, AAM probably isn't doing too well either. They're probably cutting every corner they can as they make axles for GM and Chrysler.

I towed a way-too-heavy gooseneck trailer back in December with my '05 2500HD 6.0L. Towed it about 200 miles. Right after the trip I changed the rear axle lube. It smelled burnt, so I know I got it pretty hot. But the paint on the cover is still ok.

I-H8-4Ds · May 14, 2006

I suspect you just have a crappy paint job.

imonfire · May 14, 2006

I suspect you just have a crappy paint job.

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I suspect you may be right. I was going to post a picture but I cant figure out how to get it in here. Any suggestions on how to get a picture into a post?

mmmikkke · May 14, 2006

I suspect you just have a crappy paint job.

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I suspect you may be right. I was going to post a picture but I cant figure out how to get it in here. Any suggestions on how to get a picture into a post?

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Post the picture in your "garage" and then you can right click on it there and get its URL (in Properties), then use the URL to post it in this tread.