Rear Differential Rebuilt

[Alan Reagan]

I had a humming/drone start at 60-65 mph about 3k miles ago. It would only do it when the truck was warmed up and seemed and would start right away at temperatures above 80 degrees. I took it to the dealer and they found the gear lash was out of spec. It had already put wear marks in the ring gear. They ended replacing the ring, pinion, carrier bearings, etc. and that solved the problem. The mechanic told me that he had done one the previous week that was making the same noise at 45 mph.

 

[jkalchik]

Alan, how many miles on it before the rebuild? And what sort of usage, i.e. daily driver, heavy hauling, etc? Warrantied?

 

[Alan Reagan]

15k miles before the rebuild. Moderate hauling and daily driver. Hauling is usually 5-10,000 lbs. Complete warranty rebuild. The mechanic said the gear lash was not correct from the factory. They put the 90wt gear lube in which I will probably change to the 75-140 before long. The rebuild completely cured the drone. It was very annoying once it got hot.

 

[Deleted member 995608]

I've read that others have had the same issue. Glad it was fixed.

 

[HorseMan-AR]

Good that they got you fixed up - just in time for the "free" differential flush/fill too!

 

[Newsa]

Good that they got you fixed up - just in time for the "free" differential flush/fill too!

My dealer didn't tell me about any free differential flush/fill. Is that only on the2015's?

My manual says change at 20,000 miles if you do alot of hauling/towing or used as emergency vehicle

 

[HorseMan-AR]

I meant it was free with the service work...free in a sense. I think my book calls for 15k, but I'd have to check. I've always done mine early, just to inspect the gears and get the gunk out.

 

[Mingoglia]

Great. I have a '15 Longhorn which is stepped into a long bed mega cab. If this ever happens to me I'm sure the dealer will blame it on the stretch. Oh well, gotta live I suppose.

 

[Newsa]

I meant it was free with the service work...free in a sense. I think my book calls for 15k, but I'd have to check. I've always done mine early, just to inspect the gears and get the gunk out.

My manual says 20,000 with heavy towing. I'm doing mine this month. Thanks for the heads up

 

[Newsa]

I do light towing 1/4 of the time. But I'll do the service anyway. I typically do more than what's called for earlier than it's called for

 

[gsbrockman]

My manual says 20th with heavy towing. I'm doing mine this month. Thanks for the heads up

You must be looking at the 1500/2500/3500 Gas engine maintenance schedule. The Ram Truck Diesel Supplement is in 7,500 mile increments---there is no "20,000 mile" service interval on RAM trucks with diesel engines.

 

[Newsa]

Yeah, didn't check the diesel supplement. Will do, thx

 

[Newsa]

Just dropped my rear differential cover and drained the fluid. It was real hot out there in the sun, so I will fill it tomorrow.

But the weird thing is that I didn't see a tag on it telling the rear differential ratio and specifying that it is limited slip.

I thought standard practice was to label the differential. I have my build sheet (window sticker) from when it was new saying at it's 3.42 & limited slip.

Anyone been under there & see if the differential is labeled some place?

 

[HorseMan-AR]

Yeah, I have never seen a label of sorts. I believe the HD trucks some standard with limited slip. What are you going to fill it with? 75/90? How many miles did you have on the fluid?

Just dropped my rear differential cover and drained the fluid. It was real hot out there in the sun, so I will fill it tomorrow.

But the weird thing is that I didn't see a tag on it telling the rear differential ratio and specifying that it is limited slip.

I thought standard practice was to label the differential. I have my build sheet (window sticker) from when it was new saying at it's 3.42 & limited slip.

Anyone been under there & see if the differential is labeled some place?

 

[Newsa]

I got some Amsoil 75W-140. I am in Miami FL. So ambient Temps are always warm here.

Almost 16,000 miles. 4000+ towing. Probably could have gone another 10,000-20,000, but I wanted to dump those microscopic metal particles out that come during break-in.

Fluid was not at all burnt. Light amber with grey metallic particles suspended

 

[Cummins12V98]

I will be dumping my rear diff fluid soon. I have 3,700 miles in it and will be running AMZ/OIL severe gear 75/110 per their recommendations.

Did the same on my 11 Dually then pulled the MagHytec before trading at 65K and the gears still looked new. A lot of 30K combined towing with 3:42's.

 

[gsbrockman]

I will be dumping my rear diff fluid soon. I have 3,700 miles in it and will be running AMZ/OIL severe gear 75/110 per their recommendations.

Did the same on my 11 Dually then pulled the MagHytec before trading at 65K and the gears still looked new. A lot of 30K combined towing with 3:42's.

Same for Valvoline Full Synthetic GL5 75W90.....ran it in my 2003, 2007.5, 2013, and my 2014 with great results. The insides always look like new with 1000 miles on'em !!!

 

[Newsa]

The gasket for the different rear cover was in good shape. Going to reuse it.