Hey guys,

I have a question...I have owned my 08 for 6 months and the paint has started to flake off of my rear differential cover. Of course there is now surface rust on it (we don't see a lot of rust in the desert).

Anyways, what I'm getting at is do you think my differential is getting too hot or is it normal for this paint to flake off?

 

An 08 with paint peeling off of the rear diff. I thought that all of the 08's have the aluminum diff cover that's bare (no paint)? I even put one on my 05 to replace the steel cover.

Unless you or someone else painted it, or swapped it for a steel cover, aluminum won't rust.

 

Nope, brand new truck...08 F250 Lariat with 4.30 gears. And it's painted but now it's a nice rust color.

 

I wouldn't call it "normal" for the paint to flake off.
Now the big question is whether it is due to overheating, or just a cover that didn't get properly cleaned before painting.

I would recommend getting one of those nifty infrared non-contact thermometers. It will be great for this, and will come in handy for other tasks in the future.

After driving for at least 1/2 an hour, crawl under and take a reading off the lower half of the cover. You usually have to get the thermometer within a couple inches of the surface to get an accurate reading.
I have a thermo sensor permanently installed in my diff with Mag-Hytek cover. I usually see about 100 to 130 when running empty, peaking to about 250 to 275 while towing.
If you see anything over 200 while empty, or 300 when towing, I would take it to dealer and get it on record that it is running hot, in case there is a problem.

Or drive 1/2 hour empty. Crawl under and spit on the lower half of cover. If it sizzles or steams off quickly, it seems way hot too me. If it doesn't, try tapping it with knuckle and then finger. It should be warm to very warm, but not searing hot.
If it is doesn't feel HOT, order the new aluminum finned cover and install it. Rust gone, and it will run cooler as well.

 

Good input thanks. I'll get right on it.

 

mine in aluminum...that is all I have seen on the 08's.

 

That's strange, is it unpainted aluminum? My truck is a job 2 build and has a painted cover.

As I said above I have the 4.30 LS with the camper package, etc.

 

I havent seen a painted cover from the lot either. Just plain old aluminum

 

maybe that is the issue, mine is a job 3? Didn't start looking till early summer so I am sure all I looked at was job 3 trucks.

I does sound like it is running hot though. Did you check the level of gear oil in the diff?

 

Not yet...I will do that this weekend though. I once owned a Monte Carlo (I know...it was the only and last CH*** I ever owned) that the diff locked up on 3 weeks after I bought it because the diff fluid was low.

If it's low, I'm going to make the dealer top it off and check the gears (while I watch!!).

 

Just to remove doubt, does it look like this (steel)



Or this, 2008 (aluminum) cover

 

Definitely steel.

 

same thing happened on mine 06

 

Did you paint or just clean the rest of your diff? It looks great. I just put the aluminum on mine as well, old one cracked, I like the spitting method but I have the infrared temp sensor so I'm gona check my temp this weekend.

 

I think the finned aluminum cover is only on the diesels.

It's somewhat normal to see the paint peeling on these steel covers. Some of the earlier SD's, they actually rust through and leak.

Bring it to the dealer and let them mess with it - OR - replace it with the finned aluminum cover, they are pretty cheap.