Rock crusher diff cover....

Nurse

Member
Put one of these on my rear d44. If I fill the axle up to the bottom of the fill plug, gear oil will puke out the vent tube and past the spindle seals(warn full floater kit). After replacing the seals twice I finally held up the original cover to the rc cover and marked where the factory fill level was and then added gear lube to that Mark. Now it's always in the back of my mind if I have enough lube back there. I have a lot of money tied up into the axle and don't want to burn it up. Just wanted to make sure anyone else here didn't have an idea.

The cover does get pretty warm. I can hold my hand on it for a little while before I have to let go. But keep in mind I probably only have, maybe, 500 miles on these new gears/locker.
Thanks for the help

-t
 
You're over filling the rear end. A good rule of thumb is 1 inch below the fill plug on a stock location.
 
Maybe this is naive, but shouldn't you go by what the owner's manual says, as rough guide anyway? I want to say that the capacity of a d44 is 1.5 qts or thereabouts. True or false? That's about as much as I could put in mine before it starts dribbling out the (stock) cover's fill hole.
 
Yes of course, however he is running a aftermarket diff cover which could dramatically change the fluid capacity.
 
yes of course, however he is running a aftermarket diff cover which could dramatically change the fluid capacity.
I see your point, but I think "dramatically" might be a overstating it a little. No doubt it would increase available volume, but I wouldn't think it's going to be doubled or anything like that. Then again, his pinion angle is something I don't know, and that will play a part in how much oil it can take before reaching the 'top', yes? The more tilted back the diff is, the lower the fill hole will be and the more the increased volume of the cover matters.

I could be wrong, but I was thinking two quarts of oil total, to compensate? I'd be curious to know how much oil nurse used in filling the diff up to the level of the fill hole.
 
For example, the paticular diff cover I am running litterally doubled my fluid capacity. That to me is dramatically. The ruff stuff covers are not double but certianly do increase fluid capacity. The point is that in a stock location to the bottom of the drain plug is over filled. Your point is a good one on the pinion angle.
 
for example, the paticular diff cover I am running litterally doubled my fluid capacity. That to me is dramatically. The ruff stuff covers are not double but certianly do increase fluid capacity. The point is that in a stock location to the bottom of the drain plug is over filled. Your point is a good one on the pinion angle.
Wow, that is a lot. I would not have thought that much, but I guess you don't know until you try it.

I have the factory cover on my rear diff, with the very low fill plug location.... And I've got 3* shims to point the pinion up somewhat. Last time I filled it I had to drive the rear of the Scout up onto ramps in order to get enough angle to put about 1.5 qts or so in there. I'll be going to 6* shims soon, so next time I fool with diff fluid I'm going to put on a cover with a higher hole :)

is there another rule of thumb for diff fluid level if you've tilted the diff? Like, high enough to reach the pinion bearings or something?

By the way, at this last fluid change I switched from mobil 1 to redline diff oil. I have to say it seems to make my Powr-Lok work a little better.
 
Buy a ruff stuff cover and put the fill hole where you want it, that is one of the best solutions out there, plus they come with a drain plug so changing your fluid is way eaiser and not nearly as messy. Not to mention they are really bullet proof.
 
Yes, I really, really like the RuffStuff cover! (seen it before.) it would be my first choice* for a beefy cover, partly because of the drain plug. That's a rare feature on diff'l covers for some odd reason. And partly because of the added capacity. It obviously has more volume than the factory style cover. That and it's just a nice clean design.

But... It has a movable fill plug??? How does that work? It looks pretty fixed in the picture.

* if money was no consideration. I don't know about spending $100 on one cover. I could get a 'thick stamping' factory style cover (with higher plug) for $25 from some Jeep vendor I found. It's not as tough, or easy to drain oil, but $75 buys a lot of rtv. I was actually thinking of trying those red-colored reusable diff'l cover gaskets. Do you know what I mean? If they are worth a darn, maybe you should look into selling those as well?
 
I can put 4 1/2 quarts in mine before it starts puking out the fill plug hole. I new that was way to much fluid, but was just curious if anyone had the same cover and how much they could run before gear lube started running out the breather or past the seals.

Thanks
-t
 
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