KAMA 554 Front Drive Repair

[DwayneB]

Hey Rob, Thanks for all the great photos. Your front drive line looks exactly like my 354 so, it'll be nice to have the photos if'n I ever need em.
I don't see how you have time to do all the work and document the process as well.
That poor KAMA was never meant to be used as a cat 980 so, i think it's held up remarkably well!!!!

 

[Ranch_Hand_Supp]

Hey Rob,
I have seen that happen to other makes of tractors.

Can you see / tell if the gear teeth are / were messing correctly. Not making contact to close to the end of the tooth. ???

The front wheels have to slip while in 4x4 on all tractors. One must keep the rear tires grabing the ground.

Ronald
Ranch Hand Supply

 

[3RRL]

Rob,

I didn't realize that your loader was afermarket and not something that your tractor was designed to have. It makes more sense to me now that I think about that part of it.

I think that with your background, skill and attention to detail, you will rebuild it as good, if not better then it was originally designed. With it failing at less then 500 hours, I worry that this might happen again. I'd do the same thing, but I'd also be thinking about a replacement axle in the back of your mind. Just like now, you won't know it's coming until it happens. If this is something that has a 500 hour lifespan, then it might be worthwhile going to a different axle.

Eddie

Hi Eddie,
Thanks for the advice. I did get a couple spares of the gears and as Chip mentioned, he has more in stock if I need them. I too am disappointed at the wear incurred at only 500 hours, but on the other hand, the 500 hours saved me a ton of money with all I've done on my home project. I know you've seen some of the threads about the tractor use. I'm hoping with most of the hard dirt engaging chores behind me, the front gears will last much longer now. One good thing is the gears are separate from the axles themselves. They slip/tap on and off the axle splines.

Of course I am disappointed that I have to make this repair as it comes at a bad time. But I don't want you to get the wrong impression about the Kama tractor. For example, in my business ... the machining business, I used to buy top of the line milling machines, lathes and CNC equipment. Brand names such as Bridgeport, Makino LeBlond, Deckel, Gardner, Cincinnati, and others like that. I always found a way to make them do what they were not supposed to do. LOL ... When abused them to cut larger than specified materials or passes, I would wreck them too.

 

[3RRL]

Rob, how long have you been a member of this forum? Lots of info on here. I like the photo gallery. I always click on the photo tab to see the latest pics the members post.

Scott, I've been a member since October of 2005, but used to browse the forum before that when I trying to learn about tractors.

 

[3RRL]

Hey Rob, Thanks for all the great photos. Your front drive line looks exactly like my 354 so, it'll be nice to have the photos if'n I ever need em.
I don't see how you have time to do all the work and document the process as well.
That poor KAMA was never meant to be used as a cat 980 so, i think it's held up remarkably well!!!!

LOL Dwayne, I have to agree with you on that point.
I hope you never have to do this repair, but it is a lot more simple than that pile of gears makes it look. I got to thinking also that the other gears such as the large ring gear, it was hardened and unscathed. Not a scratch on it. Those small miter gears were completely chewed up. So I wonder if the Chinese assembled with soft gears in that area as a protective wear component to protect the more expensive ones? I know I do that a lot in my business, design a component (the least expensive) to take all the wear and periodically change over.

 

[Flyhiflylo]

Hey Rob,
I have seen that happen to other makes of tractors.

Can you see / tell if the gear teeth are / were messing correctly. Not making contact to close to the end of the tooth. ???

The front wheels have to slip while in 4x4 on all tractors. One must keep the rear tires grabing the ground.

Ronald
Ranch Hand Supply

Ron good point... My buddy has a Kabota and blew the front end out pulling a dead hourse out of it's stall...

 

[3RRL]

Hey Rob,
I have seen that happen to other makes of tractors.

Can you see / tell if the gear teeth are / were messing correctly. Not making contact to close to the end of the tooth. ???

The front wheels have to slip while in 4x4 on all tractors. One must keep the rear tires grabing the ground.

Ronald
Ranch Hand Supply

Hi Ronald,
I checked for the mesh between gears. You are aware that all the housings and plates are assembled with shims to set the correct running clearance between the gears. This is especially important when using miter or bevel gears since having them sit too close together causes the addendum and dedendum to interfere. From what I could tell, especially in this photo, it looks like the ones that wore were set pretty far apart. You can see the root base of the teeth still exists.



But that does not necessarily mean it was set up incorrectly, but it could be the case. One thing I found interesting was that each casing had exactly the number of shims shown in the parts manual. In real life, the number of shims would vary depending on the tolerances of the gear shape and height of gear hub. What we do is design that theoretical distance but then fill it as needed (via shims) determined by actual fit. Like any machined part, there are tolerances to take into consideration when fitting them together.

With that said, I have no way to determine if the involute arcs actually were set correctly or not, with proper spacing between teeth. Because that is what you want touching when setting up gears like that. That involute arc on each gear tooth is the curved shape that makes contact with it's mating gear tooth. To set that distance, I would need to set it up and bench test the clearance ... to determine where the base hub SHOULD be in relation to the mating gear, in order to determine the number of shims required (if any) to get perfect mesh.

I will most likely do it by "feel" in the field repair. I have lots of experience with gears and I should be able to get it shimmed correctly upon re-assembly. Hahaha...I hope!!

 

[Flyhiflylo]

Rob you can also shim the backside of the gear where it pushes on to the axle... You can test very quickly the mesh pattern in the field with persian blue.

 

[DwayneB]

LOL Dwayne, I have to agree with you on that point.

I remember one photo early on where you had a boulder in the bucket the size of small volkswagon.
I have to be careful myself My koyker loader will lift way more than the tractor can handle.

 

[Flyhiflylo]

I remember one photo early on where you had a boulder in the bucket the size of small volkswagon.
I have to be careful myself My koyker loader will lift way more than the tractor can handle.

Ha ha no kidding... That was huge....