40 Ford Rear Hub

J

John R

Well-known member
The 40 Ford rear hub has two snap ring grooves. Why? The outer one is familiar – it retains the grease seal. The inner one – positioned so it could retain the bearing - seems unnecessary. Is it used?

Also, in searching the Green Book for information, I see the GB lists part 78-1184-B “washer (rear wheel bearing thrust)” (used 40-48). That "washer" is rather large (2.8” OD x 3/8” thick). Where does it go? Being 3/8" thick, it could fit between the two snap ring grooves. But why?
 

Attachments

  • Rear Hub Snap Ring.jpg
    Rear Hub Snap Ring.jpg
    35.5 KB · Views: 30
Last edited:
You raise a very good question.

Below is an OEM rear hub off my 40 Ford that was in the trunk when I bought the car in 1963. It also has 2 snap ring grooves. From what I found i came to believe the caged roller bearing is inserted and then the grease seal. I always thought that only one snap ring was then installed in the outer most groove not the lower groove close to the bearing. The original grease seals were leather. Replacements are rubber.

However, the posting of your question is causing me to reconsider that I may be incorrect.
Here's why:
The total depth of the cavity into which the bearing goes is 2.327 in
The total height of the bearing is 1.669 in.
This puts the surface of the bearing adjacent to the lower snap ring groove.
A snap ring could be installed in this groove to retain the bearing.

This leaves enough room for the 3/8 thick part 78-1184-B “washer (rear wheel bearing thrust)” (used 40-48) that you mentioned to be inserted as the ID of the hub is 2.80in.

With THAT 78-1184-B washer installed there is still enough room for a snap ring to be installed in the very top snap ring groove to retain the grease seal. This tells which way the grease seal should face.
https://www.fordbarn.com/forum/showthread.php?t=5217

I sure hope someone can expertly clarify which installation procedure is correct as I may have been doing it wrong for the last 63 years. Thanks, Jim

Could it be that somewhere along the line folks just decided to do away with the second snap ring and 78-1184-B washer since the snap ring is such a pain to remove and reinstall?
 

Attachments

  • IMG_7139.jpg
    IMG_7139.jpg
    43.8 KB · Views: 23
  • IMG_7140.jpg
    IMG_7140.jpg
    43.6 KB · Views: 25
  • IMG_7142.jpg
    IMG_7142.jpg
    53.9 KB · Views: 32
  • IMG_7155.jpg
    IMG_7155.jpg
    34.1 KB · Views: 24
  • IMG_7326small.jpg
    IMG_7326small.jpg
    44.4 KB · Views: 26
  • IMG_7327small.jpg
    IMG_7327small.jpg
    45 KB · Views: 31
  • IMG_7358small.jpg
    IMG_7358small.jpg
    87.7 KB · Views: 29
Last edited:
Thanks for the photos. Your rear hubs are like mine, with the second snap ring groove. So the mystery of why it's there continues.
(BTW, leather seals are still available.)
 
To me that second grove is not a snap ring groove. Compare it to the first. Looks like a shoulder for a seal.
 
Tony, After careful examination I can assure you that both grooves are the same and will accept a snap ring although that doesn't mean that another snap ring was used. There is absolutely no shoulder. The hub is sitting on my desk in good lighting. Speedway video shows the use of only one snap ring.
https://www.youtube.com/watch?v=BofwMnThuvI

Still doing more searching.
 
Last edited:
I believe 1184 is part of the brake drum hub assembly. The hub casting was assembled with parts that form the rear brake drum, wheel studs and hub and sold as one piece. So it is already in your hub. If you look at any of the drawings for the rear axle assembly it does show the bearings, snap ring and seal but the 1184 washer is not shown.
 
Terry, Are you saying there is a separate (washer) piece that is located inside at the bottom of the rear hub cavity where the bearing goes? The bearing slides in and rests on this piece that is an integral part of the hub?
 

Attachments

  • IMG_6670.jpg
    IMG_6670.jpg
    50.9 KB · Views: 21
Could be part of the hub assembly I suppose. But then why would it be shown as a separate service part when the hub and drum are not shown separately? Plus it seems to be virtually impossible to replace that "washer" - it is 3/8" thick.
 
19Fordy said:
Tony, After careful examination I can assure you that both grooves are the same and will accept a snap ring although that doesn't mean that another snap ring was used. There is absolutely no shoulder. The hub is sitting on my desk in good lighting. Speedway video shows the use of only one snap ring.
https://www.youtube.com/watch?v=BofwMnThuvI

Still doing more searching.
Click to expand...

Just a thought on the inner groove that it was probably an undercut for defining where the seal diameter ends and the smaller bearing dia begins. There is a difference so a small shoulder exists. I dug out a '40 hub and bearing to look at. When machined, they just duplicated the groove. Just my opinion.
 
Tony, Your assumption may be true. Did you measure the ID of where the bearing rides and also the ID of where the seal fits? Are they the same?
 
You must log in or register to reply here.
Back
Top