Rear differential covers

Diff fluid is cheaper than repairing a rear axle. Not to say it will fail but preventative maintenance is a good thing.

I do my rear axle about every 30k miles. I do my trans every 25k.

"I was going to change my dif oil but the service manager just told me that synthetic is standard in newer Fords so don't worry about it."

I highly advise reconsidering that! How many miles are on your truck?

falconbrother wrote:
Due to this thread... When I got home last night from a day of pulling the camper (5800 dry say--6800 wet) I checked my differential. It was hot as a firecracker (technical term). Too hot to hold your hand on. Not that it matters I guess. It was working hard pulling through about 100 miles of low mountains. I just serviced it before the trip. I have a small-ish pinion seal leak. I will fix that in a few days.

I found this info on a different forum:
Eaton conducted tests on oil/component durability during the late 1980s early 1990s

Their intent was to maximise seal and gear life and to allow the maximum OCI possible for their Heavy Truck gearboxes and diffs when using 75w-90 and SAE50 gear oils

They found;
a) components should not be operated at consistent temperatures above 250F
b) Intermittent operations to 300F do not harm the components or oils (synthetics)
c) Oils with a sulphur/phosphorus additive package activate rapidly above 230F.
d) A poor additive package in a synthetic lubricant may not be as good as a good (thermally stable) additive package in a mineral oil

My experience is that synthetic gear oils (75w-90 and SAE50) usually reduce operating temps by from 10-20C

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=516393

It sounds like you can get firecraker hot to the touch without causing problems (other than burning your fingers) and generally synthetics can take a little higher temps than the mineral oil that is referenced above.

I was going to change my dif oil but the service manager just told me that synthetic is standard in newer Fords so don't worry about it.

Due to this thread... When I got home last night from a day of pulling the camper (5800 dry say--6800 wet) I checked my differential. It was hot as a firecracker (technical term). Too hot to hold your hand on. Not that it matters I guess. It was working hard pulling through about 100 miles of low mountains. I just serviced it before the trip. I have a small-ish pinion seal leak. I will fix that in a few days.

No reason to run an aluminum cover for off roading. Diff temps are basically a function of load*speed+ambient temp. Since off-roading is generally speed, except for desert-running, temps shouldn't be an issue.

all my years of being in a jeep I never had one, I would have been concerned about hanging up on it, always ran the stamped steel.

Now for towing heavy it will help keep the read end oil cooler, the alum heat sinks pull some of the heat out of the pumpkin. Is it required, most likely not, but some manufactures are putting them on the HD trucks that have higher tow ratings.
My previous F250 never had one and I never had an issue nor did I ever consider putting one.

1jeep wrote:
No, they actual cover that holds the oil in which is typically stamped steel.

Sooooo- is this something I need for off-roading? Or just an OEM replacement? Sorry for being so ignorant; this is all new to me. Especially since I can't crawl under my truck and look around like I used to...

I don't doubt it is worth it and a nice niche ram has, I'm surprised the other 2 haven't started offering it.

1jeep wrote:
Cummins...that is the nice part about the rams, I wish all 3 were optioned with air bags.

It really is a good system. Would buy again!

No, they actual cover that holds the oil in which is typically stamped steel.