Front Drive Repair Kama 554

[3RRL]

Some of you know how I have used my Kama 554 in land preparation for my new log home, garage and barn. I have just over 420 hours on the meter, but more actual hours than that since the meter was not working for a couple months when I first got it.

From estimates I got for all the dirt work, the Kama 554 has paid for itself already more than double (conservatively even more than that?). That is not to count the many hours I have maintaining my 1/2 mile long dirt road and all the other projects over the last 3 years.

In the thread
3R Home and Barn Project

I mentioned breaking the front drive while working in the mud in 4 wheel drive. I was shifting vigorously from forward to reverse to get the mud moved off my road, trying to get out of the heavy rain storm. In addition, I had a loader full of mud for added traction (about 2500 lbs at least) which is a definite NO-NO for 4wd systems. I had been warned several times that damage might occur to the front drive but I ignored the warnings ... and that's exactly what happened.

Anyway, here is the start of the thread for the repairs.

[3RRL]

I will include many photos since this project is quite involved. However not so bad that one should steer away from it. It is very doable, even for an old hack like myself at my rural campsite.

Upon dis-assembly, I saw that the tie rod ends, the swivel ball shaft was worn too. Probably due tot he same reason ... exposure to heavy loads in the front end loader bucket and also to climbing over rocks and obstacles. That places a great amount of stress on the steering linkage. After jacking up the front up with the bucket and securely blocking it with big wood, I proceeded to drain and split the front wheel drive assemblies. There are drains in each front wheel drive and also on under the differential . I also had to drain the entire front differential casing to get rid of the steel chips in there. I still have to wash it all out with Kerosene before re-assembling.

[3RRL]

Since I actually did the dis-assembly back in December, I might accidentally skip a step or two, so if you have questions, please ask.
I also wanted to add that I did have the Kama operation and parts manual to work with, but there were no instruction on how to do this exactly. So I had to "feel" my way through the dis-assembly as I went along and using only those tools I had at my rural camp.

The other thing I did was order all the parts by looking at the parts manual before I even started the dis-assembly. I ordered every component for both sides, gears, shafts, bearings , spacers, seals, "o" rings etc.... everything I thought was associated with the front drive even the front differential drives and shafts which you'll see in these photos. I did that because I knew it might take some time for them to get here from China. Plus, I didn't know how long the dis-assembly was going to take me to do, or when I could get to it.

Anyway, I ordered them through my good friend Scott (flyhiflylo) and he added them to the existing order for Loretta's tractor (284 Jinma). He said it would be no problem for him so I took him up on his offer. He got prices and quoted me an outstanding price for all the components. Then, on top of that, told me it would be NO CHARGE from his Kama representative!
How's THAT for a good service deal?
Thanks Scott!!!

[3RRL]

So here's the story...
When it occurred, I could feel when I did the damage.
The tractor lurched and missed a beat as the front drive felt like it had busted a tooth while operating. Of course I was a half mile from camp and in the rain and not quite done with my chores. I decided (against better judgment of course) to continue working the road so my contractors could get up it the next day.

Well I kept grinding those gears in the front end to shmush even more.
It did no good to take it out of 4 wheel drive after it broke, because then the front wheels locked up. So I put it back in 4 wheel drive, finished the road work and drove it back to camp. Brutal!!

Every once in a while the right front wheel would stop turning but the tractor just pushed it as it skidded forward. Then I'd stop and back up to loosen the jam and go forward again. I had to do this several time before I got back to camp. All this time KNOWING my front drive would be toast. That is why I say I tortured the tractor beyond all reasonable doubt. I butchered it.

Now, here are some pictures showing some of the wear and breaks.
During the dis-assembly, I kept working my way back from the outside to the inside. I pried open the main drive hub and found the large ring gear and miter gear seemed OK. Excellent as a matter of fact. They are hardened.



The main drive housing is held on by that thing I have in my right hand.
It allows the drive housing to pivot when turning the wheels.



I removed the main drive hub leaving the shaft of the reducer gear in it's housing. That reducer gear housing slips into the large main drive housing and is housed by needle bearings. Of course the needle bearings all fell out.

The vertical shaft has miter gears on each end. The top one engages with the drive shaft miter gear and the bottom one engages with the large ring gear. The shaft transmits power from the front drive shaft to the large ring gear. The large ring gear is attached to the wheel hub and lug nuts. The shaft was galled pretty good from broken teeth and metal chips falling down.
Fortunately, that area on the shaft meant nothing, since it only passes through a clearance hole in the housing.

[3RRL]

Next was to remove that vertical shaft housing so I could see the miter gear inside it and also exposing the front axle shaft itself and the miter gear on it.



Here is a close up of the miter gear inside that vertical shaft housing and also the the front axle shaft gear.
You can see those are the ones that are shot and how chewed up they are. They are also the smallest diameter gears of the bunch but also the least expensive. I'm wondering if they (the Chinese) designed it that way in case of failure?
The first two are the ones from the right wheel which locked up initially and you can see the teeth are completely gone. The last photo is of the left side which was starting to go too.

[3RRL]

I went a little further with the dis-assembly taking off the gear from the front drive shaft and then removing the drive shaft from the front differential. First I removed the retaining ring to get the gear off, but found out later I could have pulled the whole axle out and removed the gear later.
The last photo is a shot of all the gears from just the right side front drive unit.



That's about as far as I got before taking a break. I was pretty discouraged.
Later that night I warmed up sipping my coffee over a warm fire by myself.



I will have to inspect the front differential gears too, but I'm pretty sure they are OK. In rotating the axles, it felt pretty smooth. If those gears are OK, I will leave them, but in any case, I will flush out the drive shaft housing for sure. The new parts had not arrived yet, so I had to wait for them to come in.

Rob-

[3RRL]

Larry was coming out to help, but the parts didn't arrive until after he went home. He did ask me about the zerk grease fittings in the drive units, the one on the hub, and here's my reply.

I did find the grease fitting you were talking about and I remembered your post about them. It is the one on the outside of the hub that can be lubed near the lug nuts. However, after analyzing mine, at least, I found the one fitting on the outside of the hub greases a bearing which might be isolated from the gear oil? It is a bearing behind the large ring gear and sits in the center of the drive hub, so I'm not so sure gear oil would find it's way up that high? It could certainly get to it if it splashed around though, or if the oil level was high enough. However to be safe, I will continue to lube that one.

The other one (not in question) was on top of the drive where the pivot is. so that one needs to be lubed since it is isolated completely from the gear oil and drive gears.

One thing that bugs me is the shaft in the wheel drive is vertical and held in with needle bearings. They are not cased and fell out. I can see an assembly problem there. I would have used cased and raced needle bearings. Now we have to stuff them all in there again...even the new bearing. I can see that being a small PITA to re-assemble.
Rob-

[psj12]

Use heavy grease to hold the bearings in place during assembly, just like in a U Joint bearing. The grease should rinse out during operation if that area is flooded with gear lube.

[3RRL]

Well, I finally got my Kama completely repaired during that period where Loretta's tractor arrived. It has been a hectic several weeks to say the least. I have some photos, but unfortunately none technical enough to show the step by step repair taking place.
Then on the other hand, some of you are probably saying Thank God for that! ;D hahaha

Anyway, I got a bunch of gears, bearings, shims, seals and stuff for the repair. But as I said earlier, the only real damage was to the two sets of miter gears. Both the left and right drive axle and reduction gears were replaced. I also replaced a couple bearings that might have had some shavings in them, just to be sure. Then also all the "O" ring seals and a couple retainer clips.

[3RRL]

Prior to that, Loretta and I spent an entire day cleaning the other gears and components and getting them all organized for the re-assembly. This turned out to be a major PITA as I soon ran out of room and tables. There were a lot of parts that I needed to "look at" so I'd get the assembly done in the right order.

[3RRL]

What started out as a nice weather weekend soon changed.
After cleaning each part I started to assemble the individual gears and pressing bearings into their races etc. I was able to use one of the home made milling/grinding vises I had at camp for much of that.
One of the time consuming assemblies was putting in each individual roller for the needle bearing inside the cast hub. I greased up the inside sleeve and also my fingers so I could pick those little rollers up and stick them in place. Then I inserted the shaft which fit back in nicely.
Anyway, I got to a point where I could start assembling the hub and front drive housings when it started to get dark.

[3RRL]

It really didn't take as long as I thought, but working under the circumstances of snow, hail and rain the next day, I found it quite annoying. At first I put on my rain gear and continue working out by the tractor. It got so wet and muddy that I decided to move all that crap (again) onto the tent decks and use the dinner table to finsh assembling the front drives. Of course we had to clean the components from splattering mud (again) before continuing. Here are a couple shots of that and the night before.



It got pretty bad and Loretta decided to take a video of the hail storm and rain to show what it was like trying to work near the tractor during this crap.
Of course Wes was just having a blast running around in this stuff.

[3RRL]

To end the story, I finally got the front drives back on each side and re-mounted the tires. I had set all the gear to gear clearances by hand, feeling for gear movement and play so it would not be too tight. I ended up using less shims in every place than were there before.
I also reconnected the tie rod and ends and power steering cylinder. I checked and adjusted the toe-in to about 1/2" narrower in front than in back of the tires. I did not do anything to the tie rod holes in the casting, deciding I could do that later, but snugged them down with washer spacers to be sure they were tight. You can see I tried it out in the deep mud again.

[3RRL]

I wanted to get the tractor back up and running so I could get to doing some road repair from the water damage. I managed to get the Kama knee deep in the mud, trying out the front drives. Everything worked perfect again so once again, I am a happy camper.

The week after that Ken(quikduk) came up and used the tractor and even cut some deep gutters with it.
I don't think he even realized I had just done that repair.

[mariner]

Hi Rob,

You have done a great job on documenting the whole process - great stuff. I really don't know where you find the time to do all this work.

Thanks for sharing .

mariner