MX429

My truck has about 9.5-10k on it now. I pull quite a bit with it, and I would say probably close to have the miles have been with some sort of trailer. Whether it be my 5x8 utility trailer or my 36ft race trailer where I gross over 20k.

I noticed that the paint is coming off of the rear end cover. The paint that is left on there is brittle and bubbled up. It looks like it has gotten so hot that it is burning the paint off. This is the first time I noticed this, as I took a close look at it yesterday while thinking about the MagHytec covers.

How worried should I bee about this? I know they get hot while towing, but hot enough to burn the paint off?

GMScott

Be VERY worried and get the fluid changed!! You'll probably notice the oil foamy - NOT GOOD!! Happened to me and I had to have the entire rear re-built!! Under warranty, but still $100.00.

MX429

I was going to change the fluid myself, but now I am thinking that this is something that the dealer should see.

MikeyB

I recommend upgrading the rear cover to Mag-Hytech or PML for added capacity and use 75w-140.
The flaking paint on the diff cover is normal.

MikeyB

coparam4x4

Happened to my truck also, just changed to Valvoline Syn 75w-140 and repainted the diff cover. I pull a toyhauler and live in AZ where it's HOT so that's why I went with the 75w-140. BTW what do you all think about Valvoline Syn? It says it's full synthetic. I would have put Amsoil in but I wanted to change the fluid asap, didn't want to wait for mail order. I will be putting the amsoil in another 15k anyway.

djbikeman

Mine is doing the same thing. IMO it's cheap paint on an non-prepped and non-primed surface.

JPR Ram

the only way to know for sure is to check the temp. if no gauge is mounted, get one of those infered guns. tow for awhile, stop and "shoot" the diff for a temp reading. then you'll know; high temp or bad paint.

CD in NM

You could do as JPR Ram has suggested and check out your towing temp. Lots have reported the paint problem and have never towed, seems like a bad paint job for sure. Dodge has changed the req on diff fluids and now recommends the 75w140 so if it were me I'd change the fluid. I did mine with Amsoil 75w140 and also added the MagHytec cover at the same time. The fluid that came out looked more like gray paint than anything else. That seems to also be the normal experience.

CD

mitternocht

I’d let your dealer know about it, just so you have a record, however from what I’ve read on here the paint coming off is normal. From what folks say the AAM gears have tight tolerances and will run hot especially when new. The paint came off mine so I had to hit it with a rattle can.

I don’t think the factory paint is any good either.

Certainly change those diffs; that factory fluid that goes through break-in gets nasty in a hurry.

Highway 4x4

I have thought of an oil cooler for the rear diff. I know somewhere on the cover there is enough oil preasure caused by the gears at highway speeds to move the oil through a cooler then returned at the top of the cover. But I just took the easy road and bought a Mag-hytec. Full syn Red Line here.

patoka pirate

I really like the mag h rear cover. extra capacity and it looks good and makes maint less messy. the temp gun is a good idea i'll try that when i pull a boat this summer. and yes the factory fill in my rear diff looked like a milky mess when i drained it too. i refilled with mobile 1 syn.

supersonictoys

how about driving it around a while and jump under it and feel the cover with your hand?

GasganoFJ60

Paint peeling isnt that big a deal. But when you change your oil, I recomend using an Amsoil gear lube. The heavy-duty aplications can go up to 500,000 miles without being changed, provided water/mud doesnt get inside.

nobull60

Mine did it also so this is what I did to make sure it never happened again.

FastTaco

I was kind of ticked too when my brand new truck was rusting already. When I changed my diff fluid I sanded it good and hit it with some rust resistant paint.