Dana 25 with Bendix U-Joint question

Mike_B · Post by **Mike_B** » Wed Jan 15, 2020 9:14 pm

I've got my 1953 M38A1 Dana 25 apart for my restoration and I need help in understanding the Bendix Joint.

The previous owner/mechanic filled the U-joint cavity full of standard wheel bearing grease and the axle just carved a tunnel in it, so I pulled the axles and put them in my parts cleaner. During the cleaning process one of the axles fell apart. Looking at the maintenance and the operations manuals I see how to put it back together, but fail to find an explanation for what the small staked pins purpose is. Can someone explain this to me?

Thanks,

Mike B

OKCM38CDN · Post by **OKCM38CDN** » Thu Jan 16, 2020 8:22 am

If I remember correctly the pin holds one of the balls in the center of the axle for the others to float around... there should be a hole in one of the axle halves and a hole in one of the balls put them together and the rest go from there. They need a bit of nudging to get put back together but they will go...

Post by **wesk** » Thu Jan 16, 2020 10:42 am

Actually he is asking about both pins.

Mike_B · Post by **Mike_B** » Thu Jan 16, 2020 1:57 pm

Thanks for the drawing Wes make it easier to ask my questions...

My #4 pin is still in place, but the rest fell apart during cleaning. Is this anything to be worried about?

I think I got it now after additional research...the #3 ball pin hole is drilled deep allowing the pin to be pushed in flush during assembly and the last step is to shake the #3 pin into the center ball and lock it in place with the #4 pin which keeps it from falling back into the deep hole. Right?

Thanks,

Mike B

Mike_B · Post by **Mike_B** » Thu Jan 16, 2020 2:07 pm

Two of the balls measure .8710" and two measure .8725"...the center ball is smaller at .8115" . Are the different sizes an issue or is that normal?

Mike B

Post by **wesk** » Thu Jan 16, 2020 9:26 pm

The replacement balls have optional sizes which I would assume is for either matching size as close as possible or for reducing clearance with knuckles as much as possible.
A-6288 center ball
A-6289 = .872"
A-6290 = .873"
A-6291 = .874"
A-6292 = .875"
A-6293 = .876"
A-6294 = .877"
A-6295 = .878"

Mike_B · Post by **Mike_B** » Thu Jan 16, 2020 11:53 pm

Thanks for the info Wes!

I'm going to put it back together tomorrow and check the back lash per the manual and see how bad it is...will let you know what I find...

Mike B