4wd Not Engaging on Kubuta L355SS

[rbargeron]

No, it's anything but obvious. The drawing in the L355ss WSM is vague about the number of collars/washers on each side of the double gear. But interestingly the L345 illustrated parts list shows a version with 3 collars, and includes an alternate version with 4. :confused2:

Up to a certain serial no. they use a thick one 22 and a thin one 23 on the same side - with another thick one 22 between the gear and bearing. In the inset they show a newer version with 4 - one 22 and three 23's. The parts list calls 22 a thrust collar and 23 a washer. They don't list different versions of snap ring 11.

A couple ideas - these are not helical gears so they have very little end thrust. I wouldn't be very concerned about using a thinner snap ring. I also wouldn't be shy about putting in whatever parts take up the slop and leave room for an oil film. That's what the pro's call "select fit".

The driveshaft center bearing is gone? That would sure explain some of the noise. Another beach day may be in order.....

 

[grayw0lf]

I may have found something. While staring at the diagrams today at work, I realized that the diagrams do not show a snap-ring between the bearing to the rear of the 4wd gear & the thrust collar in front of the bearing. There is clearly a snap-ring groove & it is a perfect fit to secure the bearing in place, but it is Not in any of the 3 diagrams I've looked at.

This probably clears the clearance issues up, but does bring up another concern. There is one thrust collar between the new $66 bearing & the gear, with the grooves on the thrust collar facing the gear. When in disassembled it, the face of this bearing was eaten up by the non-grooved backside of the thrust collar. I'm sure the exploded diagrams are all right, but i can't help but question the logic of the thrust collar & the washer (with oil grooves on both sides) between the gear & the snap-ring, while the bearing & gear get only a single face being lubricated.

 

[rbargeron]

On the factory diagram of the PTO shaft (their panel 045000) it shows a circlip 10 located behind the bearing, with a thrust washer next, then the double row bearing that runs inside the gear. Does that add up?

The only thing I can think of on the other issue is if the bearing started getting rough the inner race might stop, scuffing on the shaft and the flat side of the collar? Does the shaft look rubbed?

Looking forward to reading the outcome, and how quiet it is :thumbsup:

 

[grayw0lf]

The shaft looks pretty good, no galling or blue hot spots. The bearing was still tight & smooth, despite its face being chewed upon.

I put it all back together last night. Getting the halves of the tractor all lined up was a bit of a challenge, as expected. It took 3 jacks & no small amount of patience. Hopefully everything will be nice & oil tight!

Tonight I'll put the 4wd driveshaft back in. Hopefully that should all be easy enough. The previous owner had some thick washers atop the pillow block bearing... not sure what that's about, but I guess we'll see!

Thanks again for all the help!

 

[grayw0lf]

So, its about time I give an update. I ran her hard for 4-5 hours last Sunday & she did great. The noises in 2wd are gone. 4wd is still "ching-ching-chingey," about like it was when I bought it. I'm not too worried about it at this time. The tubes that the 4wd driveshaft go through are not round, but oblong & have also been welded back together at some point in time. Basically, I'd guess that they were flattened a bit over the years & running down trees & such.

I think it'd take a bit to fix it, but I have doubts that it would make any difference, other than making it sound better. (Knocking on wood!!!)

Hopefully it'll be a few years before having to split her again, & if I do need to, so be it. Its not terribly difficult or the end of the world. (It is a bit of a PITA though!)

 

[rbargeron]

......The tubes that the 4wd driveshaft go through are not round, but oblong & have also been welded back together at some point in time. Basically, I'd guess that they were flattened a bit over the years & running down trees & such.....

A good middle bearing might help splines and couplings last, but if it's not "tinking" too bad it may run forever. Congrats on fixing up your 4wd gearbox :thumbsup: