I have broken my brush hog gear box and am trying to fix it. So this is somewhat off topic, but I am also getting ready to rebuild a model T rear end so the info gathered should help both projects. My main question is about the back lash and wear pattern to the gears. What happened is the brush hog bounced over a big stump, and pushed the main "pinion gear down shaft" upward, sheering a snap ring that holds the bearing spacing. which in turn let the snap ring pieces eat up the bottom bearings. So I ordered the parts needed and all new bearings and seals. The main "pinion gear down shaft" and bearings, with spacer shims ect came out in pieces and I was not able to see the true order of dis-assembly, But there is really only one way for it to go back together. I also have a parts diagram showing the placement of all the parts and shims. The way the main "pinion gear downshaft" is made, there is no adjustment, "it is where it is". Now the cross shaft for the ring gear is assembled as a unit with the bearings and ring gear being spaced and held in position by spacers on the shaft. Then the whole assembly fits into the case between two large snap rings (one located on each side of the case). The assembly is loose in the case between the snap rings by about .060. There is a shim pack of different thickness of shims that you use to shim the assembly between the bearing and snap rings for a tight fit, and it also allows for you to achieve a proper backlash by allowing for a tighter or looser fit to the ring and pinion depending on what side you put the spacer shims. Now that all seems to be straight forward, but after I have it set I have a distinct "click, click, click to the gears as I rotate them by hand. The gear teeth are in no way binding as they rotate and I have about .010 backlash at any given point. The teeth of the pinion are not even close to bottoming out in the ring gear. You can see the original wear pattern to the ring gear as a slight discoloration to the shine on the teeth. The gears are in almost new condition. I took a blue marker and colored a couple of the ring gear teeth. By rotating the shaft by hand I was able to get a good display of my new wear pattern when it rubs off the blue marker. It is almost the exact same pattern as the factory wear pattern. The wear pattern is in the center of the tooth. I will post a few photos showing the wear pattern, You should be able to see the factory pattern and my "blue marker" wear pattern. I had already put the entire brush hog back together and it was extreamly loud as to the gear noise. It was almost silent before. Im about to the point to put it back together and say "to &^%# with it". The three seals that fit on the shafts are not re-useable. You have to destroy them to get them out. They cost 65.00 for the three seals. When it goes back together this time Im not taking it apart again. Ill use it till it slings itself apart.... So any suggestions, what am I doing wrong or not seeing. ??? Thanks ...
donnie!! you can do what i did, take an old axle housing cut off the tube then cut windows in it then you can use feeler gauges to check it with. charley
Donnie, if the gears are used, finding the exact "quiet" position is going to be hard. In my experience, if you have a good contact pattern, in the center of the tooth, as you seem to have, there is not much else you can do. Since the only adjustment is on the ring gear, adding or removing shims will only change the pattern up or down on the tooth. In other words, increasing backlash will move the contact outward towards the toe of the ring gear teeth, removing backlash will move the pattern inward towards the heel of the teeth. Your pattern looks good so I would go with it. The noise should decrease as the gearset wears in.
John, I agree, that the pattern looks good and since there is only the in or out direction of adjustment all I can do is change the backlash and move the pattern in or out from toe to heel. The thing I can not figure out is what changed ..??? The gears were almost silent before ... What changes would happen "IF" I could move the pinion gear 'up". If I am thinking right, moving up would move the wear pattern toward the center of the ring gear. (It actually is another bevel gear, but Im calling it a ring gear). I could make the pinion move up by making a shim to go between the pinion gear and the bearing. I would then have to remove a shim the same thickness below the bearing to get the snap ring back in but I could do it. The shims below the pinion bearing are not designed to be moved from bottom to top of the pinion bearing to achieve the different mesh, they would be different size center hole. . And the parts diagram does not show any shims above the bearing. I just do not think moving the wear pattern toward the center of the ring gear will change the noise either. And it is a lot of work if it did not change anything. So it may be the neighbors will have to get ear plugs .. because it was very very noisy ..
Donnie, you could try running the gears in with TimeSaver 'till the new pattern is established. The whine is caused by the teeth as they leave the mesh. Like plucking a string or wet finger on the rim of a crystal goblet.
A friend just bought a 1908 Brush one cylinder that has been in storage for many years. It's an older restoration and has not been registered for many years. We have not been able to find the 4 digit S/N in order to have DMV verify the car. Do you know where the S/N is located? Appreciate your help.
Les Von Nordheim
Why don't you get the numbers off the seals. I bet a local bearing house will have them, and at much less cost. When you turn the input pinion can you feel the clicking. It could be a piece of metal in one of your bearings or something is binding and kicking the shaft back and forth or it could be something kissing a snap ring. Both of my bus hogs, one modern , one ancient make noise but neither screams. It would be unusual for a pair of straight cut bevel gears to be quiet.
Ted I tried the seal number thing. It appears they are a unique seldom used thing. The seals are almost 20.00 dollars each and plus tax. they come to about 65.00 for the three of them. My Kubota dealer was actually cheaper than the bearing supplier. I went ahead and took it apart again and made a special shim washer to move the pinion gear up. I added a .028 shim above the bearing and that moves me .028 up. Im happier with the shim arrangement, but that is about all I gained. The noise is the same and I did move the wear pattern toward the center a very little bit. Not enough gain for the effort. But now the pattern is almost exactly the same as the factory pattern. Still in the center of the tooth as before heel to toe. But now it also matches the original factory pattern better as it is now slightly closer to the center of the ring gear. Im going to put the seals in, oil her up. and run it till it dies .... quietens up, or keeps a screaming .... The weeds need cut .... but I hate it when things do not make sense and I can not find an obvious answer. It was quiet before it should be quiet now ... OH Well .... Thanks for the input guys ... Les I sent a PM message about the Brush
Donnie, do you have a cab on the tractor? If so, turn the radio up.........
Good luck. Our 13 foot BushHog is on it's last legs, with three rebuilt gearboxes.
Like the old guy in the nursing home moving in with the young nurse said to a concerned old friend.... "when she dies she dies"
Well its back together and mowing brush. Its a lot quieter now, but still not as quiet as it originally was. I can live with it, and the neighbors may not call the law on me. I believe a lot of the problem stems from the replacement parts. Even though they are all the same part number and I got it all from the Kubota dealer, the parts are different in some measurements. The main difference is the thickness of the bearings. They are thicker by about .010 to 015 each bearing. That forces me to move the shims around to different locations than they were originally and also probably moves the wear pattern. That is probably why they designed it with shim packs in the first place. But you would think they could get closer to size than what they did. And I can not blame it on the foreign parts. The brush hog is American made by Land-Pride in Kansas. Thanks for the support and input ... this was at least a good learning exercise before the important re-build of the 27 tourings rear axle assembly ... have fun and be safe ...