Universal Joint Rubbing Wear Problem

[19Fordy]

Took out a transmission today and noticed the end of the universal joint facing towards the transmission had been rubbing against the bearing race in the case and the end of the u-joint was worn down as shown in photos. The special spring washer and bolt to secure the universal joint was tight.
Any idea what could cause this rubbing and can this U-joint be reused as it "feels" tight?

Another question: the Vin # on the transmission is 99A-2078925 and the transmission case is 40-48 Ford.
Question: What vehicle did this transmission come out of originally? There is no traditional "Star" stamped before or behind the number, just a "curly Q" kind of stamping.

Also, I have another 40-48 transmission that has no VIN number opr anything else stamped on the top of the case as usually found. Could this mean that at some point in its life a new factory case was used by a dealer but, they didn't bother to stamp it with VIN number. There are no grinding marks on the cast iron. Looks totally like unaltered cast iron.


Thank you.

[V8COOPMAN]

.

Transmission is out of a '48 Ford or Merc! That funny little 'squiggly' at the beginning of the number is actually an "8". '48 Fords and Mercs all shared serial numbers. DD

[Kurt in NJ]

The bolt holding the joint tight to the shaft was loose, and possibly the bearing jammed up some and the inner race spun, there could also be wear on the mainshaft

[Will D]

Looks like there is a star under or over the 8 that makes it look like a"squiggly". Look close and you can see the star at the end as well about a digit space away from the 5.

[V8COOPMAN]

Originally Posted by Will D

Looks like there is a star under or over the 8 that makes it look like a"squiggly". Look close and you can see the star at the end as well about a digit space away from the 5.

Will D stole my glasses......HE is correct! Two stars, almost plain as day!! DD

[19Fordy]

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Gosh, I got to get new glasses. Just went out and took two more photos.
Now I'm seeing stars too. Thank you all for opening my eyes.

Come to think of it, that U-joint bolt may have been lose but, the u-joint still seems nice and tight with no slop and a nice sliding fit. I now have to figure out why the U-joint bottoms out against the bearing.
Will be asking more questions about this.

Thanks again. Jim

[Mac VP]

The U-Joint is supposed to bottom out against the rear bearing inner race. This is what pulls the mainshaft back against the front face of the ball bearing, thus locating the shaft correctly in the transmission. There would normally never be any rotation between the bearing and the u-joint since they are normally clamped tightly against each other. I’d guess that the universal joint was not tight against the rear bearing. With the wear seen in your pictures, you should replace the u-joint and most likely the ball bearing too. When you slide the replacement joint onto the mainshaft, it should bottom out against the rear bearing inner race. Then you would install the bolt and special washer inside the joint. We use blue locktite on the bolt with a fresh lock washer.

[19Fordy]

THANK YOU Mr. Van Pelt for that "golden info." I wasn't able to find this info in your book so I am very glad you responded to my post. Jim

[Terry,OH]

Another cause of the U-joint wear could be a seized rear bearing with the main shaft and U-joint rotating in the inner rear bearing inner race. Make sure the main shaft does not have wear. This could also be old damage.

[19Fordy]

Thank you Terry.

[JWL]

Terry is right on. That wear can happen if the shaft speed is not directly linked to the bearing speed so even a loose u-joint would not wear unless that rpm differential existed. Both the bearing and the shaft are suspect.

[19Fordy]

Thank you JWL. Appreciate your input and knowledge.