The Stovebolt Site Forums The Parking Lot Big Bolts Rear end diagram/grease question

Does anyone have a assembly diagram for a 30-40s 1.5 ton rear end? I took it apart probably 2.5 years ago and have a few questions for re assembly.

1. There are the dished grease "caps" are these supposed to have any sort of seal? My dad seams to think it should have some felt of similar material to help seal, is this correct?

2. The top hat assembly itself, it has the brass screw to fill with grease, are they supposed to be completely filled with grease?

3. What grease do you guys recommend?

Thanks guys

no one has any insight into my questions?

Maybe my questions do not make any sense?

Hy CORPO, I read your question yesturday, and I didn't understand your descriptive terms for the parts you were asking about, I thought that maybe someone who used the terms "dished grease caps" and "top hat assembly" would come along and understand what you were asking about. Perhaps if you were to find an exploded diagram of the rear axle in question, and use the terms referenced in that diagram, we may be able to answer your questions, hope that helps.

Some pictures would help, not sure what you are calling a "top hat assembly"?

The dished grease caps, are they what hold the axle shafts in the hubs? like this https://lh3.googleusercontent.com/-uiuF7fsgjTY/UG3ktL81kHI/AAAAAAAAARA/czrxlrXFILc/s912/IMG_2104.jpg
If so then a thin paper gasket and very lightly some Permatex #2 is what I use. In a pinch I have also used a little silicone and no gasket, also seems to work.

Grigg

All right thanks guys, my terminology needs work.. the "top hat" would be the Hub assembly itself, there is a brass screw on the portion the wheels slide over that opens to the bearings on the hubs.. is this cavity supposed to be fully packed with grease... and what type of grease?

As far as the other piece I will have to get a photo.. it is a thin stamped piece that somehow slid over the axle tube and prevented grease from getting into the drum brake area... still vague I know.

I'm unsure, is your service manual any help.

I'd take a guess that the brass screw/plug is to oil the bearings with the same oil as in the rear axle, newer axles don't have that provision. the oil should get there on a hillside or fast turn, always oil them or some grease at assembly though. I would not pack the whole thing full of grease just as I never do on front hubs.

Grigg

Grigg, thanks for the input, I don't have a service manual.

The bearings definitely had a thick grease in them when I disassembled the rear end, not a oil like you would find in the differential. I agree that it shouldn't be fully packed, its just a matter of convincing my dad of that..

as far as the "dished cap" I don't have a photo of the piece, but I do have a photo of where it installs, I just need to figure out if it had any sort of soft seal on it

thanks again

http://i385.photobucket.com/albums/oo291/mack1416/IMG_0947_zpsfcde7c28.jpg

I see the picture but still unclear what's going on..
Reasonably sure you'll have a seal on the diameter just below the shoulder your arrow is pointing to.

You should find a service manual for your truck. One of the best tools a mechanic can have.....

Grigg

P.S. you know the rest of your axle housing is buried in the concrete floor right??
What are you up to?

Hy CORPO, I think the "dished cap" is the inner hub seal o.e.m. p/n 3681195 = National 5850. If there was grease in the hubs and it is meant to be that way, then there should be some sort of seal at the outer end of the hub, to keep the oil in the diff. from washing out the grease. One method of doing this was to have a "rubber seal" in the outer wheel bearing adjusting nut, but as far as I know those have been made of unobtainium for awhile now, hope that helps.

Corpo, Go to this website. While this is for Chevy and not GMC it should be close. They have both service and parts manuals and will probably help you with the info you are looking for.

http://chevy.oldcarmanualproject.com/index.htm

Alkay 3

Thanks for the link.. i found this page for a 37
http://chevy.oldcarmanualproject.com/chevyowner/37ctim/37ctim27.html
but the diagrams dont show up!!! ahhh

What I did was here... you read it back in the day.. I did it back in 09.. time flys
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=634936&page=1

Hey Corpo --- you should also check out the "Arhives" on the GM Heritage site. They have manuals for most of the vehicles they ever built online for free. Mighty handy resource.

GM Heritage Archive

Corpo,

First off, what year and make of truck are we talking about? I'm assuming this is a Hotchkiss type rear? Torque tube type? Or is it after 1940?

Also, the 'dished' parts your talking about sound like the grease/oil deflectors that just sit on the inner axle prior to installing the hub. The grease seal should sit in the hub after you install the bearing, than the hub assembly can be slid on the axle.

Jeff

Jeff,

My truck is a 36 1.5 Chevrolet, the rear end was a torque tube style Eaton 2 speed. However. I am unsure of the exact vintage of my frame/axles when I looked up the VIN my truck should have been a short wheel base and it was not.

Yes, I believe you have come up with the name I have been searching for, grease/oil deflectors. I am under the assumption that there was no soft seal on the inside surface of these deflectors is that correct?

I removed my drums and never pulled the bearings, the drums were free of grease on the inside, therefore can I assume my grease seals are still working fine?

You wouldn't happen to have a picture of what a proper installed grease seal looks like?

Thanks for your help

I believe the brass plug in your hub is to allow you to add the right amount of oil directly to the hub rather than having to tip the truck to get oil from the diff to each side.

Tad

Corpo,

Heres the closest thing I could come up with to what my '47.1 had originally. This held the felt seal.

The felt ring sat in the groove like this.

Most other trucks I've worked on just had a dished grease deflector installed on the axle housing and the seal itself was pounded into the hub itself after the bearings were installed in the hub.

I'm not familiar with much beyond '39, but I can't imagine the setup changed much with the hub bearings and seals. Do you have any pictures of the inner side of the hubs and the grease deflector?

Jeff