Snowblower PTO shaft alignment

[severtki]

I picked up an old George White 5' snowblower for my B3300SU Kubota. Seller demonstrated its operation on his tractor and everything looked smooth.

Bought it, hooked it up, and it runs great if the blower is about 8" off the ground. When I drop toward the ground, the drive shaft starts chattering and knocking about pretty badly. The angles look like they're within a reasonable range (see picture). The knocking was worse until I extended the top link to adjust the angle a bit.

Guessing the u-joints have gone bad (see pictures) and I would need to replace drive shaft, yes? Any pointers on how to replace since it's attached to the blower unit? I can't quite tell how it's attached or how to remove, and of course it's at an awkward angle. Is the closeup picture showing a cutoff shear bolt that might have be driven out?

Something like this work? https://www.completetractor.com/dri...s-14006542-ab5111wy138r/#.X-I875feVnU.twitter

Thanks for any help with this!

 

[RCW]

How much overlap do you have left in the 2 halves of the drive shaft?

Wondering if an issue of length vs. bad U-joints.

When you raise it, the shaft shortens, and all is good. Set it down and it lengthens...maybe a little too much.

 

[severtki]

How much overlap do you have left in the 2 halves of the drive shaft?

Wondering if an issue of length vs. bad U-joints.

When you raise it, the shaft shortens, and all is good. Set it down and it lengthens...maybe a little too much.

Good point. I just marked the shaft in both positions and measured the overlap: 8" when raised (works) and 7" when lowered (chatters). Shaft seems pretty tight, so I wouldn't imagine it's too short.

Either way, I guess I would need to replace the PTO shaft? Looks like there may be a rusted set screw of some kind:

 

[PoTreeBoy]

Good point. I just marked the shaft in both positions and measured the overlap: 8" when raised (works) and 7" when lowered (chatters). Shaft seems pretty tight, so I wouldn't imagine it's too short.

Either way, I guess I would need to replace the PTO shaft? Looks like there may be a rusted set screw of some kind:
View attachment 52439

I can't tell for sure, but your driveshaft may be out of phase. If so, slide it apart and rotate the 2 parts 90 degrees relative to each other.
When the yoke on the tractor is vertical, the yoke on the blower should be vertical also.

 

[severtki]

I can't tell for sure, but your driveshaft may be out of phase. If so, slide it apart and rotate the 2 parts 90 degrees relative to each other.
When the yoke on the tractor is vertical, the yoke on the blower should be vertical also.

Good thought, but this shaft is slightly rectangular and only accepts the other half in two of the 90degree positions.

 

[BobInSD]

My IH-80 shaft looks similar to yours. (On mine) there is a key under that set screw. Mine also has a cross bolt going through the shaft and the pto shaft, so I need to take out that bolt, then back off the set screw, then pull the pto shaft off. Yours is even rustier than mine, so it might need a little persuading. Don't forget that the other end is in the expen$ive gear box and seals.

Note that this is not a sheer bolt on mine, it's a keyed shaft and the sheer protection is at the other end.

Having somebody else make you a shaft would be spendy, (around $400 around here). If the one you linked meets your hp requirements that might be worth considering. If you get it on a workbench swapping the u-joints should not be too bad. I've managed to do them with a vice (no press). Yours look fairly rusty, so YMMV.

 

[rAzkid]

Measure the length of both inner and outer shafts. They should be the same length and the overlap at the longest length (down) should be no less then 1/2 the length of a single shaft. If you are lucky, which I wouldn't be, the u-joint on the tractor end may be bad and would be the easiest to replace. It's a lot cheaper to replace the u-joints rather then buying a new driveline! To replace the complete driveline or just the u-joint on the blower end you will still need to remove the yoke from the blower shaft so I would take the cheaper way out and replace the u-joint.

 

[GreensvilleJay]

it's easy to test ujoints.
grab both sections of a ujoint firmly and try to turn one to and away from the other. ANY movement and it's time to replace it.
the real 'fun' will be getting the blower section of shaft off....

if possible get 3 new crosses BEFORE starting the ordeal..

 

[severtki]

Thanks, everyone! Good information, and I'll try all of this out and report back. PB has had several days to do its magic...

 

[thebicman]

You may also have a seized or partially seized u joint. That would explain the sound. Everything should be smooth with no resistance but without any slop. Keep us informed as its always good to know the fix.

 

[severtki]

Measure the length of both inner and outer shafts. They should be the same length and the overlap at the longest length (down) should be no less then 1/2 the length of a single shaft. If you are lucky, which I wouldn't be, the u-joint on the tractor end may be bad and would be the easiest to replace. It's a lot cheaper to replace the u-joints rather then buying a new driveline! To replace the complete driveline or just the u-joint on the blower end you will still need to remove the yoke from the blower shaft so I would take the cheaper way out and replace the u-joint.

Picture of outer/inner shafts. Inner is 15.5", outer is only 10". Overlap is ~7" when fully extended, 8" when in shorter (raised) position.

Good news is that the u-joint nearest the implement seems pretty good -- no play and it's easy to move all directions. The U-joint on the tractor is good on one axis but on the other, moves loosely in the near-center area and then is very difficult to move past that point. I'd guess that's the u-joint I should start with!

 

[severtki]

it's easy to test ujoints.
grab both sections of a ujoint firmly and try to turn one to and away from the other. ANY movement and it's time to replace it.
the real 'fun' will be getting the blower section of shaft off....

if possible get 3 new crosses BEFORE starting the ordeal..

Is there a way to size the u-joint needed before disassembly or are these pretty standard sizes?

Edit: spent 90 minutes pounding the darn thing out, but got it out and have now identified the part #. Link here if this is useful for anyone else:

Moog Universal Joints Chart | By Size | Moog

Every Moog Ujoint by size available in an easy to read chart. Learn about Moog premium universal joints and find the one you need by measurements. Moog certified parts and techs.

www.moog-suspension-parts.com

In-stock at my local auto parts store, so things are looking up. Will update when it's installed.

 

[SidecarFlip]

Think I'd get on Agri-Supply's website and buy a complete new driveshaft. Not that much really. That one is pretty rough and missing the safety guards anyway. I'd say the blower end the gearbox input shaft is splined and the PTO end fits the spline with a through bolt holding it on. My big Lucknow blower is set up like that.

 

[rAzkid]

Clean and relube both shafts before reassembly. Spray brake cleaner inside the outer tube to ease cleanup. You should install a new safety shield also. Watch out that none of the needles drop out of place during assembly!

 

[severtki]

Ended up going with new ujoint at tractor end, as well as all the suggestions of rAzkid, and tried it out. Works great, no clunking anymore!

Will look into new driveshaft someday, but this is probably doing to be a light-duty implement for me in SE Michigan.

Thanks for all the help, everyone.

 

[rAzkid]

Glad it worked out for you and you're ready for the snow!