The Stovebolt Site Forums The Shop Area Driveline Slip yoke

I have a 47 loadmaster 1.5 ton with a two piece driveline. While replacing the pinion seal I decided to go through the rear drive shaft. The rear u-joint needed to be replaced and the front one was fine but I disassembled it anyway for inspection. While it was apart I noticed there was no plug in the end of the slip yoke. Shouldn't there be a soft plug with a small hole drilled for excess grease?

Hy Dave Parque, welcome, yes there should be a cap there with a small hole in the center, sometimes there are two or three welds to hold it in place. You might be able to find a concave frost plug of the appropriate size and weld it in place, hope that helps.

Thanks 3B, that should work fine.

Do as you may, but I would not recommend welding of any sort of a forging. A U-joint is
one of the most highly stressed parts on any vehicle. The yokes gain their high strength
from the forging process, which compresses the inner grain structure to follow the
shape of the part. A weld introduces a stress riser breaking up the smooth flow of the
grain.
This is a slip joint from a 3600 which is similar to the one being discussed. The grease
retainer plug sits in its bore and is swaged during manufacture in a number of places
around the rim. This also disturbs the grain but it can be looked at as bending the grain
structure like a rubber band rather than cutting it. Any machining on a forging is
designed to follow parallel lines of grain, and avoid cutting thru them.

http://www.pbase.com/dennygraham/image/158972318/large
http://www.pbase.com/dennygraham/image/158972319/large

Denny Graham
Sandwich, IL

Great advice,Denny I was thinking depressing the center of a convexed soft plug with a couple of swaged points would hold up fine.

They hold up under water pressure in engine blocks so I don't
see why it would't in the yoke. Do you have the slip joint
out? Is there any evidence of the old one being swagged in?
If so, then it might be difficult to get a properly sized
freeze plug in place past the dimples.
If it were me, I'd put the proper size freeze plug in place
if I could get it past the dimples. Then set it and fold over
the dimples a little more. I'm sure that's the way the
original one was installed.

Kind of unusual to be missing that grease retainer plug. One
would really have to work at it to remove it. Possible that
someone removed it to clean the yoke and couldn't find or fit
a new one in place so they just decided to leave it. You never
know what these trucks have been subject to after 65 years.

DG

Rather than swaging, why not use a high strength epoxy like Devcon "Epoxy Steel"- - - -sort of a better-quality "JB Weld" product. If it was mine, I'd silver solder a steel plug in place.
Jerry

I rebuilt the leaf springs this last summer. Both locator pins were sheared off and axel had slipped forward an inch and a half. Possibly spline shaft punched it out, just a guess. I put it all back together for now I will address it when go through the front shaft and carrier bearing.

Thank you DG and HL for the response you guys are awesome.