Stubborn u-joint.

Dave Shepard · January 30, 2015, 07:30:40 PM

I've been trying to put a new u-joint in the pto for one of our generators. I think it's a #35. 1.25" cups and 3.21875" (3 7/32") across the cross. At first, it looked like I had a needle across the end of the cross, but I took it apart, and nothing. Tried again, and still wouldn't go together far enough to put the snap rings in. Measured, and it looks like it's about 1/32" off on the width. I tried grinding out the snap ring grooves with a Dremel tool. The grooves were rusty, but it didn't make much difference. Both the long end of the shaft and the coupler end are the same dimensions, so I don't think anything is bent. Old joint was growling, but it hadn't had a catastrophic failure. Has anybody run into this before?

Peter Drouin · January 30, 2015, 07:47:25 PM

Maybe one is metric and the other is not

Dave Shepard · January 30, 2015, 07:57:19 PM

The new joint definitely is the right dimensions for a #35. The shaft is from a WinPower generator from about 1973. No idea if that might be metric. I'll try to reassemble the old joint and get a measurement.

snowstorm · January 30, 2015, 08:10:01 PM

yup seems like some aftermarket joints are just a little different. i have run into that on ford trucks. buy a joint from napa it may go in easy or not. buy one from ford made by spicer it not only fits better it lasts twice as long. dose it have inside locks or outside?? you could try grinding the lock ring just a little to make it thiner

pineywoods · January 30, 2015, 08:54:03 PM

Tthere are aftermarket U joints out there that are purposely made non-symetrical. The yoke on one side of the cross will be different width from the other side. Commonly used for situations like coupling ford rear axles to chevy drive train or vice versa..

Banjo picker · January 30, 2015, 10:04:36 PM

If it has inside locks, you can grind the yoke just a dab on each side and get the clearance needed to get the lock on. I just did a u joint job on my Kubota rtv. Kubota joints were three times the cost of a Percision 397...just took a fraction off each side of the yoke....Banjo

coxy · January 31, 2015, 08:28:44 AM

Quote from: snowstorm on January 30, 2015, 08:10:01 PM
yup seems like some aftermarket joints are just a little different. i have run into that on ford trucks. buy a joint from napa it may go in easy or not. buy one from ford made by spicer it not only fits better it lasts twice as long. dose it have inside locks or outside?? you could try grinding the lock ring just a little to make it thiner

same here on ford u joints I grind the cap just a little to get snap ring to fit

dgdrls · January 31, 2015, 10:25:12 AM

http://www.fleetpride.com/find-branch#

I stopped monkeying with U-joints and simply
pull the shaft and relay what needs done,
saves time, effort and frustration.
Maybe one is close by?

good luck
Best
DGDrls

Autocar · January 31, 2015, 06:38:21 PM

Check the cup I had the samething turned out that one of the needle bearings fell off the side of the cup and was in the bottom.

Dave Shepard · January 31, 2015, 06:45:54 PM

That's what I thought happened the first time I took it apart, but after measuring everything, I now know that the old parts are not the same spec as the new joint. The new joint is a #35, and measures exactly as it should for a #35. I don't know why the old yokes are different, and I haven't found a replacement joint that meets those specs. I tried lapping the cups on my diamond plates, but it barely scratched them. :D I need to gain about .080" to get the new joint to work.

pineywoods · January 31, 2015, 07:25:31 PM

Sounds to me like your old joint is one of them special types intended for coupling two different size yokes together. Measure the length of the arms on the cross

Dave Shepard · January 31, 2015, 07:48:47 PM

The old yokes are the same dimension, or about .080" shy of working. I've cleaned the grooves with an abrasive wheel on a Dremel tool to make sure there is no rust in there. They simply are a different dimension than a standard #35 joint.

Holmes · January 31, 2015, 08:12:53 PM

Could heating up one part and freezing the other give you enough expansion and contraction to get it together? It is going to be COLD tonight!

Dave Shepard · January 31, 2015, 09:19:09 PM

I had it together once, but the snap ring on one side was severely distorted, and the joint was bound up. I'm not really looking for a way to make this one work at this point, just trying to figure out what is supposed to be in there.

Reddog · January 31, 2015, 09:39:15 PM

Bench grinder takes the ends right down. ;)

Don't ask how long it lasts. Cause the one I did lasted fine till it twisted like a pretzel from being kinked :D

Al_Smith · January 31, 2015, 09:51:43 PM

80 thou,it might as well be off by a mile .80 might be the thickness of one snap ring .Surface grinder to shave the snap rings maybe ???? Might work might not .

whitepine2 · January 31, 2015, 10:11:56 PM

I hate U joints sometimes all goes good and other times,
well you know. I use caliper and check out everything this helps
to get the right parts. It's a pita but saves time in the end.

sandhills · January 31, 2015, 10:25:02 PM

Quote from: whitepine2 on January 31, 2015, 10:11:56 PM
I hate U joints sometimes all goes good and other times,
well you know. I use caliper and check out everything this helps
to get the right parts. It's a pita but saves time in the end.

Couldn't agree more, I hates u joints like magicman hates sweetgums!

Corley5 · January 31, 2015, 11:03:45 PM

U-joints and I don't get along either

slider · February 01, 2015, 08:53:17 AM

Do like I do.It works every time.Find a sharp parts man that needs your sawing skills from time to time and he will dig through the books and find you what you need.It works for me.

justallan1 · February 01, 2015, 08:56:47 AM

I certainly agree on the Ford aftermarket opinions. The only thing we have in town is CARQUEST and more times than not they don't fit on certain years trucks. We now drive the extra 40 miles and go to Ford for them.
I have ground the clips a touch to get them to work. Just make sure you grind them both the same.

Ford_man · February 01, 2015, 10:50:07 AM

I hold the shaft in my hand and strike the yoke where it curves down to the shaft with a hammer.Hit it hard on each side it will spread just a little. Keep doing that till it fits. Do that with the spider in the yoke. It works.

Dave Shepard · February 01, 2015, 10:51:59 AM

If I ground the clips, there won't be enough clip. ;) Like I said, not going to try and make this joint work. If this joint fails in use, it's either going to snap the shaft on my Kubota or one of the big tractors at the farm. I know the pto's come out the back on the big tractor, but I would worry that I would have to dismantle my Kubota into 42,000 individual pieces to get the shaft out. ;) Either way, correctly fixing this shaft, finding another shaft off of something out back, going to the junkyard and getting a shaft off of something down there (which may have actually lived out back until it was hauled away :D ) or buying a complete new shaft, is going to be far cheaper than fixing a tractor in the middle of a severe storm/power outage.