Fill plug location.

[swamp rat]

On my Eaton Ho52/72 (which ever it is)

I was looking at a pic of before i started working on my truck and the plug is below centerline, i have seen a lot of pic's from this forum also showing the plug in the same position. since then i have also seen pic's of cover flipped 180 with the plug above the centerline..

Looking at a pic with the plug below centerline it sure looks to me that the diff would not have sufficient lubrication for the wheel hubs unless i was constantly turning corners.... I'm questioning if these covers were installed correctly, How does the wheel hubs receive sufficient lubrication of the level is so low it only reaches the bearings during the G force of cornering??

Anybody have a picture/print from a factory manual showing the cover???

Here's 2 links showing both

http://67-72chevytrucks.com/vboard/s...1&postcount=30

http://67-72chevytrucks.com/vboard/s...2&postcount=12

[Bigdav160]

Like you, I've seen it both ways. Full floating vs semi floating? My HO52 is long gone and the 14 bolt, I have, doesn't have a fill plug in the cover but on the side. Kind-of mid level on the pinion. Which isn't much above the lowest part of the tube



I always pack my bearings with grease anyway. Just like the front.

[kwmech]

The second pic is correct, oil level should be with the bottom of the inside of the tube or very slightly higher

[swamp rat]

Originally Posted by kwmech

The second pic is correct, oil level should be with the bottom of the inside of the tube or very slightly higher

Ya know i wish i could find just 1 factory picture showing the rear cover on this thing.

It may be incorrect but i decided to install my cover with the plug at the top, I figure with the vent in the housing pressure won't be a problem, and i can always use my finger to gauge the level and keep it a bit lower than the plug.

Besides, my plug was a leaker and i don't know if my home made gasket will be any better.

[swamp rat]

Well, i found out this does not work, the plug hits the ring gear, cant figure out how in the first pic and the others I have seen that it worked unless they had a super thick gasket, or maybe they also had to flip it over? Bottom line don't try this at home.

[vectorit]

Hmm.. Here is mine, and been in this position as long as I can remember.

[swamp rat]

Originally Posted by vectorit

Hmm.. Here is mine, and been in this position as long as I can remember.

Yep thats the stock location, i was considering doing a 180 and adding a little extra lube, but not clear to the top of the plug..

[Stocker]

I still don't understand why you want to overfill the diff. The factory level has worked for many years, in countless applications.

[swamp rat]

Originally Posted by Stocker

I still don't understand why you want to overfill the diff. The factory level has worked for many years, in countless applications.

I think mainly because my wheel bearings looked like total crap when i took them out with the level maintained, also, when i look at the level plug to me it looks like the gear oil does not reach the bearings unless the enertia from turning a corner forces the oil to the hub. Yea i know there are thousands and thousands out there, but when i seen a few picks with them turned 180 i just thought why not. End of story.

[jjzepplin]

I clocked my rear end a bit and the pinion did not look like it was going to get oil so I just screwed in a 90 degree pipe fitting and pointed it upwards and added the extra lube and now the same plug goes in that fitting. Been that way for ten years, no problems. 14 bolt though but I don't see why you couldn't do the same thing.

[Stocker]

Originally Posted by swamp rat

I think mainly because my wheel bearings looked like total crap when i took them out with the level maintained, also, when i look at the level plug to me it looks like the gear oil does not reach the bearings unless the enertia from turning a corner forces the oil to the hub. Yea i know there are thousands and thousands out there, but when i seen a few picks with them turned 180 i just thought why not. End of story.

Thanks for the explanation. I wonder if there could be some other reason your bearings looked bad? My '72 still has its original bearings. They appear to be well-oiled and still looked good last year.

[Bigdav160]

My guess is, at some time, the rear oil got low. It wouldn't take much to starve the bearings.

I always pack my bearings with grease anyway. It works in the front. Eventually the gear oil will wash it away but at least the bearings are protected on the initial roll.

[swamp rat]

Originally Posted by jjzepplin

I clocked my rear end a bit and the pinion did not look like it was going to get oil so I just screwed in a 90 degree pipe fitting and pointed it upwards and added the extra lube and now the same plug goes in that fitting. Been that way for ten years, no problems. 14 bolt though but I don't see why you couldn't do the same thing.

I appreciate the thought about the 90 deg elbow, the Eaton unfortunately is not NPT, its a fine thread, have yet to measure it with my thread gauge to figure out exactly what it is, haven't had time to deal with it, too busy with the lift kit.

[swamp rat]

Originally Posted by Stocker

Thanks for the explanation. I wonder if there could be some other reason your bearings looked bad? My '72 still has its original bearings. They appear to be well-oiled and still looked good last year.

The only explanation i could think of is if someone changed them out they may have installed them without packing them. Thanks for the reply!

[swamp rat]

Originally Posted by Bigdav160

My guess is, at some time, the rear oil got low. It wouldn't take much to starve the bearings.

I always pack my bearings with grease anyway. It works in the front. Eventually the gear oil will wash it away but at least the bearings are protected on the initial roll.

Well i absolutely packed mine the old fashioned way working the grease in using the palm of my hand and put a coating on the races too, i would be much less concerned if the hubs were isolated so the grease didn't wash away tho.