?Model B w/ brushog gear whine/vibration
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Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=33459
Printed Date: 07 Sep 2025 at 12:15pm
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Topic: ?Model B w/ brushog gear whine/vibration
Posted By: trhod12
Subject: ?Model B w/ brushog gear whine/vibration
Date Posted: 07 Jul 2011 at 2:54am
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Ok, I'm gonna try and do my best to describe this, I know it would be better if you could hear what I'm talking about, but here goes. The last time out, the B was mowing fine. I hit a piece of steel in the field (I think it was a small chunk of a 55gal burn barrell). Immediately after hitting the steel, I didn't notice any problems. About 2 passes around the field later, I started getting an intermittent vibration and what I can only describe as a horrible gear grinding sound that seemed to be coming from the rear of the tractor. Then it would be fine, then it would start sounding funky again. It seemed to occur at 2 different times: 1. when I was in a turn, and 2. when I was in heavy grass.Could this be a messed up bearing or race that is on the drive line going to the pto. I'm thinking that I have the knuckles in the driveshaft on the pto getting out of synch, and causing a vibration and binding that is being transfered to the tractor. Does this sound about right????? Is it possible that this is the slipper clutch on the brushhog kicking in and doing its job(I don't know if the slipper clutch makes any racket when it is working)??? Or do you think I'm in for a teardown of the final drive in my tractor??
Just to recap. It doesn't do this all the time. The tractor will run and mow fine, but it will intermittenly develope a vibration and a gear whine/racket. Then it will run and mow fine again.
Any thoughts you have would be appriciated, and I know it is hard for you to diagnose my problem sitting behind a computer. I'm just not sure where to start looking for this problem.
Thanks,
Blessings,
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Replies:
Posted By: Gerald J.
Date Posted: 07 Jul 2011 at 10:43am
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Yup. Could have bent the shaft, that let the oil out of the gear box, now the gears and bearings are shot from running dry. Possibly a major disaster. Gerald J. |
Posted By: Dick L
Date Posted: 07 Jul 2011 at 12:04pm
| I would first unhook the mower and drive the tractor around with the power take off running to see if you get the noise without the mower. Might could be but not likely that hitting something with the mower would do anything to a B tractor. I would think it would be in the brushog gear box or a broken or bent blade. |
Posted By: wfmurray
Date Posted: 07 Jul 2011 at 1:12pm
| The way i check the slip clutch is rev up tractor and drop foot clutch . you should get a little slippage . Just a little lets you know it will slip to much and you know it will slip in heavy cutting. You may have other problems. Good luck. |
Posted By: Auntwayne
Date Posted: 07 Jul 2011 at 7:57pm
| You need to look under the mower, make sure that something is not wrapped around the blade..... causing tough mowing in thick grass !!! And hearing it louder while turning around on end rows that were already mowed.....it would really be audible spining in dead air !!! |
Posted By: AC WD45
Date Posted: 07 Jul 2011 at 11:07pm
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Our old bush hog always made that noise. Never did find the cause. Course that bush hog was the same one that would shake and bang everytime you put it in gear, and is also the same one who's blades eventually knocked holes in the deck. Still use it but it's seen better days. ------------- German Shepherd dad 1957 Allis Chalmers WD45 #WD234847 1951 Allis Chalmers WD #WD88193 |
Posted By: trhod12
Date Posted: 08 Jul 2011 at 12:25am
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Well, you've made me feel better, at least, that I didn't destroy something in the tractor.
I will get out and fire it up in the next couple of days and see if it makes any funky noises. I'm thinking it probably won't, so that leaves me with the brushhog. I'll get it off the tractor and take a look at it to see what is going on.
THanks for your info and thoughts, I'll let you know what I find.
BLessings,
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Posted By: trhod12
Date Posted: 21 Jul 2011 at 2:02am
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I got a chance to do a little investigation on this problem. Brushhog checks out good, no bent shaft, fluid in gearbox, no bent or stuck blades. I unhooked pto shaft from tractor, fired tractor up, engaged pto reved it up, all sounded good. So for grins and giggles I hooked brushog back up to pto, turned tractor on low throttle and engaged brushog (like I always do when starting brushog), then slowly reved tractor up....sounds good. Then, while the brushog was spinning slowly at low throttle, I threw the throttle open to 3/4 throttle, and there it was.....the horrible sound of gears slipping over gear. I'm pretty sure that it is coming from the tractor, in the location from behind the axles. I would say it is in the area where the pto would engage to the drive line of the tractor. Seems like to get this sound, I need to put the pto and final drive under stress. Looks like I'll be tearing into the final drive of the tractor, unless someone has any other ideas.
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Posted By: Dick L
Date Posted: 21 Jul 2011 at 4:33am
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The power take off short shaft has a gear on the inside end that meshes with another gear. If the bearings are bad it could cause the gears to slip by each other. Just a guess in my part but I would think you could find a complete power take off unit and switch cheaper than trying it fix the old one. I have a couple of them that I robbed the ident off and on shafts out of that I could let you have the needed gears and maybe bearings out of if you want to repair yours. I am in Ohio but a half a day away. You can have the parts needed out of them for getting them. http://cgi.ebay.com/Allis-Chalmers-B-C-PTO-belt-pulley-drive-assembly-/160623250052?pt=LH_DefaultDomain_0&hash=item2565e44a84 - http://cgi.ebay.com/Allis-Chalmers-B-C-PTO-belt-pulley-drive-assembly-/160623250052?pt=LH_DefaultDomain_0&hash=item2565e44a84
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Posted By: allischalmerguy
Date Posted: 21 Jul 2011 at 10:44pm
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Do you have an adapter to make the PTO shaft bigger on the tractor so you can run the bush hog? Could that be bad?
Mike |
Posted By: trhod12
Date Posted: 21 Jul 2011 at 11:07pm
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Dick, thanks for the offer. I might take you up on that, sounds like a good excuse to dust off the motorcycle for a days ride to other side of the state. I will let you know once I get into this thing more and find out exactly what is going on. I was thinking the same thing you are saying, that maybe the bearing was going bad, and was allowing the gears to jump.
allischalmersguy--I didn't notice the overrun clutch slipping on the 1 1/8 to 1 3/8 adaptor, but you could be onto something there. I did twist one of these spacers off the pto 2 years ago. I thought that was a freak thing, wrote it off as cheap metal in the spacer. I never thought about the possibility of stripping the grooves off the spacer. I'll check into this a little more. Too hot right now, and I'm in the middle of working midnights for the next week. Great idea.
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Posted By: trhod12
Date Posted: 30 Jul 2011 at 2:20pm
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Posted By: trhod12
Date Posted: 30 Jul 2011 at 2:21pm
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Posted By: trhod12
Date Posted: 30 Jul 2011 at 2:25pm
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Ok, I pulled my pto unit off the B and found the bearing for the short shaft to the pto was gernaded. I pulled the slip gear (that engages the pto to main shaft), and found the above groove in the main shaft (see 1st picture with the pen showing the groove).
My question is, is this groove normal, or did the wearing of the bearing rubbing on the main shaft cause this groove??? Do I need to replace this main shaft, or is it ok??
Thanks for your help in advance.
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Posted By: trhod12
Date Posted: 30 Jul 2011 at 2:26pm
| The 2nd picture is to help you get oriented to which shaft I am talking about the groove being on. |
Posted By: wkpoor
Date Posted: 30 Jul 2011 at 2:33pm
| I would say that is wear from the bearing race walking the shaft. Looks like you'll be placing an ad for that shaft or a replacement PTO. Let Dick chime in and be the official say. |
Posted By: CTuckerNWIL
Date Posted: 30 Jul 2011 at 4:43pm
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Looks like the inner race has been spinning a long time. If the shaft was out of the tractor, it could be welded up and turned but a salvaged part might be cheaper.
------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: Bill Long
Date Posted: 30 Jul 2011 at 7:30pm
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Boy, do those pictures bring back memories. I could not do it now but how many gears and snap rings did I attach to that shaft, and how many PTO housings did I lift into place on the rear end. I definitely could not do that today. I really don't think it would be so easy to even bend over to get there. Getting old is very good but it has it's drawbacks.
Yes, it looks like you will need a new shaft and PTO. You may want to get one with a 1 3/8" shaft. Those adapters leave me cold. Especially with a rotary mower - a relatively heavy load.
Take good care of my favorate.
Good Luck!
Bill Long
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Posted By: trhod12
Date Posted: 30 Jul 2011 at 10:52pm
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Maybe I didn't explain this correctly.
The short shaft to the pto is actually in pretty good shape.
The bearing that gernaded was the flat roller bearing that holds the end of the main shaft into the pto housing. The end of the main shaft is what the picture is of, and has the groove that appears to be worn from the bearing failure. This bearing failure allowed the main shaft to move around, which inturn caused the gear that slides to engage the pto to fail. The teeth on this engagement gear are chewed up, and needs replaces.
What I'm just trying to figure out if the main shaft is junk due to the groove?
Also, since I have this all apart, is there anything else I should change out?? Is there anything else that is probably gonna fail on me in the near future??
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Posted By: Dick L
Date Posted: 31 Jul 2011 at 5:14pm
| The shaft will have to be replaced. I am having a problem getting a picture down loaded into this computer. I will try the old computer as soon as it comes up. This is windows 7 and the other ones are XP's Seems to be a driver problem. |
Posted By: Dick L
Date Posted: 31 Jul 2011 at 5:18pm
| Hey Bill. I have to remove the drawbar and use a floor jack. The seat is in the way also for us old stiff backed fellers. It is easier yet with the seat off. |
Posted By: trhod12
Date Posted: 31 Jul 2011 at 5:32pm
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I figured the main shaft was junk. I actually went ahead and split the tractor today, and pulled the main shaft out. I was planning on replacing all the bearings and races on the pto short shaft and the main shaft. Is there anything else, while I've got it apart, that I should replace. The gears are all looking pretty good. |
Posted By: Dick L
Date Posted: 31 Jul 2011 at 6:59pm
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I would guess not but check the clearances as you assemble it. You can tell if a bearing needs replace by looking at the cup and rollers.
Here is the picture.
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Posted By: Bill Long
Date Posted: 31 Jul 2011 at 10:03pm
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Dick L, When you are young and have boundless energy and supposed muscles you really don't think twice about an easier way. No way could I do that today. Even with the draw bar removed and a floor jack. Good Luck! Bill Long |