PTO universal joint rework

[cathead]

I can't just sit around so went looking for a project. The universal joint on the dump truck PTO was pretty worn so removed it and
thought I would see if there was a way to take out the slop. Apparently it was welded together in it's inception so I used a
4.5 inch cutoff wheel to disassemble the thing. It was a greasy mess so gave it a soak and a scrub so I could handle it.
On disassembly, the center part was worn badly but the outer wear surfaces still looked fine. I decided to braze in some material
to take up the wear. The center piece may have been cast iron but the outer tabs were apparently steel as they welded up
just fine, a little bit stiff but OK. After a shot of grease, it is ready to install back on the truck.
Brazing seemed like the best option here.



I did a little gas welding on the outside cups as they were beginning to fail.



And here it is ready to put back into service. It's probably the original part from 1967 so if I get some more years out of it, so much the better.
And, yes I could have bought a new part which likely would cost more than I was willing to pay. This way, It's back together without even
a trip to town. I was surprised that this unit had no needle bearings, just bushings I guess or maybe they flew out long ago...?

Thanks for riding along.

 

[ddillman]

never seen a u-joint without needle bearings

 

[Cadillac]

Ill second that, I've done over a100 or so pto shaft rebuilds along with driveshafts and have never seen one without needle bearings. From the pics it looks like the u joint itself is tapered and the knuckles are bell mouthed? Doesn't seem to be a reliable design IMO.

 

[Superburban]

I'm trying to figure how it was put together 50+ years ago. Can't say the bushing part was that bad of a design, it slowly wore out, instead of blowing apart like the needle bearing units do when they are shot.

 

[Cadillac]

I'm trying to figure how it was put together 50+ years ago. Can't say the bushing part was that bad of a design, it slowly wore out, instead of blowing apart like the needle bearing units do when they are shot.

Idk the caps look like their cast and ends look like steel. Could the caps have been two pieces then welded when welded to shaft ends?

 

[samstu]

These are still available. Some on fleabay "light duty pto universal joint" . But I like the shop fix better and probably easier than welding on whole new pto joint. Nice work.

 

[cathead]

Radial sloppage was reduced from about 20 degrees to essentially zero with this repair. The only part that might be cast iron is the
rotary driver piece.

I remember on one of my first jobs in high school was on a building construction site. I was given the job of
hauling a dump truck load of old construction materials( sheet rock, 2x4 scraps etc) to the dump. I backed up to dump the load
and engaged the PTO to unload. Nothing was moving so I stepped on the accelerator some and it began to raise. All of a sudden,
the whole truck shook back and forth sideways and shortly after that, I watched the PTO shaft being hurled hundreds of feet into the abyss.
Needless to say I had to unload the truck by hand........... a big lesson learned..... And a true story.

 

[aliva]

I would go to a local wrecking yard and pickup an old driveshaft with joints. At least it will have needle bearings and probably last a lot longer.

 

[cathead]

The input end is for a 3/4 inch square drive and the output end is 3/4 inch round with a keyway. It is specific for that
type of PTO so just any old driveshaft will not work. That is why I refurbished the existing drive. I did think of trying to use
an old driveshaft and it was not a practical solution to the problem.

 

[Superburban]

If you are looking to replace the shaft, Look at tractor PTO's. Tractor supply has a bunch of round, and square shafts, and various U-joint ends, and cross bearing. That is how I made the shaft for the winch operated PTO, on an old Dodge truck.