Check your splines!

marrmanu

Active member

Equipment
B2620 3pt chipper, box blade, post hole auger, custom 3pt chain box with hooks h
Jan 16, 2021
100
88
28
usa
Putting my B2620 back together and the mid front axel drive U joint line would not go onto its drive shaft. A closer look reveled this! Cost of a new U Joint $130 o_O cost of further damage o_Oo_Oo_Oo_Oo_O.
DSCN3088.JPG
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,750
2,932
113
North of Pittsburgh PA
Can't see internally, but are you sure the shaft that is inserted is not machined the same way so it can only be assembled one way?

My monitor shows so little of what is inside that wide area, but what little I can almost see does look like a spine could have broken off...
 
  • Like
Reactions: 1 user

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
6,029
3,298
113
Texas
Looks like it is “keyed” to assemble only one way…..this would keep U-joints properly in-phase.
 
  • Like
Reactions: 3 users

BruceP

Well-known member

Equipment
G5200H
Aug 7, 2016
849
367
63
Richmond, Vermont, USA
I see nothing wrong with your photo. It is normal for shafts with Universal-Joints to be keyed. (especially within the slip-yoke). This prevents improper assembly.

U-joints MUST be properly phased so the matching joints at each end are bending at the same time.

Technically: The shaft itself is not spinning at a constant speed....but the phased Ujoints at the ends cancell each other out. This is why you NEVER see a shaft with just a single Ujoint on it.

This is one reason FWD cars use CONSTANT-VELOCITY (CV) joints. There is no need for phasing becasue the velocity (rotational speed) remains constant regardless of angle. CV joints are more expensive and cannot handle the torque when compared to Ujoint of the same size.
 
Last edited:
  • Like
Reactions: 2 users

dirtydeed

Well-known member
Lifetime Member

Equipment
B2650 BH77, U27-4R2, BX23TLBM, box blade, rear blade, flail mower, Stump Grinder
Dec 8, 2017
3,012
3,623
113
Wind Gap, PA
I understand the Keyed reasoning. But, it looks like in the OP's photo that a spline actually broke. The machined edge doesn't look straight in the photo (looks like piece broke off instead).
 
  • Like
Reactions: 1 user

BruceP

Well-known member

Equipment
G5200H
Aug 7, 2016
849
367
63
Richmond, Vermont, USA
If it really is a broken spline... I would just run it the way it is. (and hope the broken peice did not get into a gearbox)

It is not the splines which hold the joint together so even if ALL the splines were to shear off, the worst it could do is spin on the shaft.

BTW: The splines on my G5200 driveshaft are nearly non-exantant. All of them come to a sharp point and there is a lot of slop. Been that way for many years and keeps on truckin. (it spins at ENGINE SPEED to drive the HST in the rear)
 
Last edited:

BruceP

Well-known member

Equipment
G5200H
Aug 7, 2016
849
367
63
Richmond, Vermont, USA
I blew up the photo and its a broken spline.
I am not sure how you can tell.

Think about the machining process to make this component. It may be easier to make ALL the splines then machine one off later when the phasing is known. This could leave behind something which APPEARS to be the remnants of a spline.
 

Tughill Tom

Well-known member

Equipment
B3200
Dec 23, 2013
1,208
1,313
113
Turin, NY
I am not sure how you can tell.

Think about the machining process to make this component. It may be easier to make ALL the splines then machine one off later when the phasing is known. This could leave behind something which APPEARS to be the remnants of a spline.
Nothing I ever broached /keyed looked like that
 

lynnmor

Well-known member

Equipment
B2601-1
May 3, 2021
1,440
1,154
113
Red Lion
Spline is broken off, not only that, but the tips of adjacent splines are knackered as well.

DSCN3088.JPG
 
  • Like
Reactions: 1 user

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,179
1,864
113
Mid, South, USA
I wouldn't be afraid to throw it back together.

Have seen them MUCH worse

typically when splined shafts are worn, they are slick. No splines left. Or extremely narrow splines.

That one is a master splined shaft. They just broke the one spline off instead of machining it. Probably cheaper to manufacture that way.
 

marrmanu

Active member

Equipment
B2620 3pt chipper, box blade, post hole auger, custom 3pt chain box with hooks h
Jan 16, 2021
100
88
28
usa
Geohorn and BruceP you nailed it! :) Your post very much makes sense and after spending 3/4 of a day and driving over 100 miles, the second dealership I went to told me this spline is not broken, it is missing to act as a key. The drive shaft end to which it mates to has a bur on the end (I almost filed it off in preparation for the new U joint) to which the U joint would line up to.
Done lots of work on cars, trucks and motorcycles, but just starting my learning curve on this type of equipment.
Thanks all for throwing in to help.
 
  • Like
Reactions: 2 users