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I noticed on the axle housing you have the larger holes on the side of the diff/ diff cover that I THINK are oil passages for the axle tubes. The two aftermarket diff covers I have, and IIRC the factory cover, seals outside of these holes, and allows oil to pass by. Yet on 3 different brands of diff cover gaskets, the holes are very small (all 3 have the same small slits). Could anyone tell me why, or would opening those up be bad or good for any reason or why they do that?
I don't know on the 10 bolt, but on Dana 60's holes similar in size and location are used for a tool to "spread" the carrier flanges to get the carrier and in and out. There is nothing behind those holes that needs lube. Everything that needs lube is basically bathed in it in the center chunk
Those holes are to increase the flow back and forth along the axle for the axle bearing lubrication. Sounds stupid doesn't it? Why would they cut slits in the gasket material if something wasn't supposed to go through it? I saw this first on an Impala forum:
"FWIW, this is/was no rumor.....the OEM gaskets did not allow for proper lubrication of the axles. This was a problem that typically (but not always) resulted in axle bearing failure at about the 70K mile mark."
I always open that hole all the way to the inside of the gasket. At the time of rebuilding any axles, I will probably never see the end of life for them regardless but it's just something I read on the internet....
but the bearings are inboard of those holes, and damn near bathed in oil at the proper fill level. Que no?
This was on my mind as well however, "damn near" isn't "always". I think the intent was just a fast ingress egress from side to side of the axle to the bearings themselves.
"When I fill the axle with gear lube, I fill until lube comes out of the fill hole. I then walk away for a few minutes, come back, and fill some more. It takes a while for the lube to seep through the carrier bearings and into the axle tubes sometimes. I can often sneak a little more into the axle housing after the tubes fill. I have done this many times on many different types of housings, using both formed gaskets and RTV on the diff covers. Never a problem, including on my own cars.
I'm sure someone will dispute this, but I have yet to see anything in print from a reputable source (IE not from someone's buddy or a forum, or even the guy at the dealership that builds 10 bolts) specifying that the gasket has to have holes, or be modified, to lube the wheel bearings."
but the bearings are inboard of those holes, and damn near bathed in oil at the proper fill level. Que no?
I believe you are talking about the carrier bearings and Drspencer is talking about the axle or wheel bearing that's at the other end of the tube.
I've always believed the holes are for case spreader tools and the axle/wheel bearing is lubed from oil that seeps past the carrier bearings and sits in the bottom of the axle tubes.
I know when I remove the axle shafts there is some oil in the tubes. I have never waited to see if it seeps and I can fill more. I am waiting for the gasket maker to set, I will try that tonight.
I didn't think about using gasket maker. You are leaving it open when you use that. I haven't seen anywhere say you had to use a gasket on a 10 bolt.
As for the case spreader argument, In my incredibly limited knowledge, the case spreaders I found aren't supposed to work for the GM 10 bolt. The holes on the DANA axles that do use the spreaders are much farther apart then they are on the 10 bolt, (14" vs 11"). Apparently all of youtube makes it look pretty easy to swap carriers in a 10 bolt making those spreaders unnecessary. I also haven't seen the holes on the dana axles, but I'm under the impression, that they are threaded for the case spreaders. They aren't threaded on a 10 bolt.
03-08-2022, 06:15 AM
Large holes on the diff housing.
