Eaton diff. cover

[shelby987]

So I pulled my eaton third out this weekend......(sitting under your truck, legs outstretched waiting for a 130lbs. piece of cast-iron to fall into your lap is not fun!)
Anyway, I decided to pull the gears and the cover, clean everything up, paint the cover, and button it all up with the new gears. My question is this, It looks as if the rear cover can go on in two orientations. One puts the fill plug just below the axles, and the other puts it just above the axles. Would I be better served to rotate the cover 180 degrees and locate the fill plug to just above the axles, or is this only going to full my axle tubes with wasted gear oil?

I was also treated to the sight of a machined groove inside of my diff. cover, thought that bump in the rear cover was factor.....turns out its just REALLY old.....but it looks like the old gear machined a very tiny clearance cut....does anyone make a rock guard for the eaton rears?

[airdale94]

bump.

I am interested in this also. Mine is on the bottom just below the axels. Don't know if it's right. I do know that the level has to be high enough to allow the wheell bearings to get oil.

[rlm316]

I just took my HO72 apart to re-gasket it and the level plug was on the lower half of the cover. With the condition of my rear I would say that this was the original position. On the front left of the carrier there is a fill port. Remove the plug in the cover and the carrier, fill thru one till it runs out of the other.

[hootlube]

Mine was lower left (looking from rear bumper forward). Fill until it runs out, (this next was Americanrider's suggestion) jack up one side of the truck to let it run into the bearings on the opposite side, wait 15 minutes, let it down, jack up the other side for 15 minutes, let it down, fill it up again. I didn't know this step, burned out my new bearings... still waiting on the machine shop to finish my housing repair. Good luck.

[shelby987]

How many quarts of gear oil does a properly filled HO52/72 hold?

If the axle is full, then you jack up one side, do you level it again to fill it, or fill it while it is tilted? I would think once its full, the oil will find a natural level within the axle tubes?

[hootlube]

Fill it level, I think, then tilt one way, wait, tilt the other way, wait, then level and top off. Oil expands when heated, you probably don't want to overfill and have it leak out the seals... anyone have other thoughts?

[hootlube]

Sorry, I got ahead of myself. I don't know how much it takes to fill one yet, I would just buy 4 quarts of (my preference is full synthetic 75-90) gear oil, maybe have a little left over.

[swamp rat]

Bumping an old thread..

Can anyone answer this part about jacking up one side, waiting and then jacking up the other side before topping it off? I'm concerned as my old wheel hub bearings didn't look that good.

I also have given thought to rotating the fill hole so its above center line but i too an concerned about pressure build up and having it leak out the hub seals..

[swamp rat]

Nobody?? Bump.

[Katrina/10]

There will be no pressure build up if your vent is open. There is no need to overfill the diff. just get the truck on a level surface, and fill till it runs out of the hole.