MTD riding mower jerky drive
#1
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MTD riding mower jerky drive
My MTD riding mower model #13AH660F352 while in gear and driving is constantly jerking. I changed both belts but that didn't change anything. It started to do it in the spring and continued to get worse throughout the summer. I'm thinking that it's something in the transmission but would like to get confirmation from you experts and also how to fix it.
Any help would be appreciated.
Any help would be appreciated.
#3
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Probably a long shot, but you might jack up the rear end and make sure the wheels are firmly attached to the axles and that neither has a broken key. A year or so ago a buddy asked me to look his relatively similar Cub that had come to a halt, and after the fact told me that it had been jerking for a while, but we jacked it up and pulled one of the rear wheels right off, hub and all.
#6
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At 20 YO this sounds like a "normal wear-out failure" rather than caused by a factory defect.
It may be easier to find when it fails outright and from your description that won't be long.
Sounds like this is a repair/replace decision and the price of parts is sometimes such that you will be on the fence with this decision.
It may be easier to find when it fails outright and from your description that won't be long.
Sounds like this is a repair/replace decision and the price of parts is sometimes such that you will be on the fence with this decision.
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I just tried jacking it up and checked the wheels and they both look good and are attached. I put it in gear to check if it was engaging and it is.
Have you ever tried taking the trans/gearbox apart? Can I get parts for it?
Have you ever tried taking the trans/gearbox apart? Can I get parts for it?
#9
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You gear box my not have a differential. Check by jacking up rear wheels. If you can turn one wheel while holding the other, you have a differential. If not you have a solid axle. On a solid axle, the rear wheel on inside of a turn must rotate the same number of revolutions as the outside wheel, yet travel a shorter distance. The result is the inside wheel jerks to add the needed distance.
#10
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With the engine off, can you move either back wheel back and forth through a small angle? This should give you a reading of total gear backlash all the way back to the engine output shaft.
#11
It probably makes a whirring or whining sound in the rear end too, right? This is a common failure for these transmissions.
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I checked the rear wheels with it jacked up and in gear and they both won't turn so there must not be a differential. While in neutral I could turn the wheels independently. One wheel with turn about 4 inches while holding the other and vice versa. If I jack it up and put it in gear and run it the mower wheels run smooth with no jerking. When I put it on the ground that's when it will jerk. It doesn't matter if I'm turning or going straight it jerks. I didn't notice any whining while it was moving.
If the tranny is bad are they rebuildable? Can I get parts for it?
If the tranny is bad are they rebuildable? Can I get parts for it?
#14
I'd replace the unit as an assembly. I rebuilt some of those years back and for the cost, time involved, and case wear you will have, I don't think rebuilding them is a viable option anymore..We just replace them or junk the mower these days.
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Hi everyone, I took a winter break and am now working on this mower problem again. I was wondering if there is oil or grease in the rear end and if it is changeable? If it has oil would it being low cause the jerking problem?
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I was out playing around with the mower this morning and the mower seems like it is engaged trying to drive and then slips or backs off from driving and then drives again and then backs off and so on which is causing the jerking. It stays engaged more when I turn hard left but straight and hard right the mower jerks quite a bit. It still jerks a little going left but nowhere near when going the other direction or straight. Do you think this indicates something in the rear end is bad?
#20
It5's internal failure, no doubt about it. You're going to have to open and repair it or replace it, or get another mower.
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Hello gents, I dropped the rear end and took it apart and found the following:
1) All of the gear teeth look good with no wear visible
2) If I rotate both shafts at the same time but in opposite directions there is no main gear movement
3) I I rotate the right shaft counterclockwise the main gear moves, no gear movement if I rotate it clockwise
4) If I rotate them both clockwise or both counterclockwise the main gear moves
5) There is minimal end to end shaft play.
Here are a couple pictures of the rear end
1) All of the gear teeth look good with no wear visible
2) If I rotate both shafts at the same time but in opposite directions there is no main gear movement
3) I I rotate the right shaft counterclockwise the main gear moves, no gear movement if I rotate it clockwise
4) If I rotate them both clockwise or both counterclockwise the main gear moves
5) There is minimal end to end shaft play.
Here are a couple pictures of the rear end
#23
The part that moves back and forth with the shift fork is where I'd start looking. Are the input shaft bearings good?
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The part that slides back and forth looks good as does the ball bearing that it slides over. By the input shaft bearing do you mean the shaft that the pulley is on? If so, yes it felt solid and turned smoothly. I may be looking in the wrong place for my problem because I don't see anything that is worn or broken in the rear end. I'm stumped at this point as to what would cause this to jerk going forward but not in reverse. Maybe the slide mechanism isn't engaging fully when put in the forward position. Only thing there is I don't see why it would engage and disengage constantly if it wasn't working right. I appreciate all the ideas you're putting out there to look at so if you can think of anything thing else I'd love to hear them.
Thank You
Thank You
#25
The piece that engages the gear on one side or the other is slipping most likely. Why, I can't say without hands on inspection. I'd clean it up and figure out why. I've seen where the forward gear is loose and worn where it fits on the shaft and allows it to rock away from the locking collar or slip on the splines on the through shaft.
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I've looked at the gears and the gear that engages one side or the other and the edges of the center gear on both sides look sharp with no rounded edges. This is also the case on both gears. I put the rear end back together and installed it back on the tractor but I have a couple extra pieces that I can't figure out where they go. One is a 10 inch spring and the other is a hook
Here is the bottom of the tractor. The piece with a slot in it which is the speed selector is only attached to the rod/spring that goes back to the brake. Shouldn't there be something else attached because the speed selector isn't doing anything now other than pulling the brake in.
From the battery opening
Just for my own knowledge how does the speed selector vary the speed with only a belt drive? Does it ride in and out of the pulley slot depending on the tension like a snowmobile does? Does the speed selector move the pulley in and out to vary the speed?
Thanks again
Here is the bottom of the tractor. The piece with a slot in it which is the speed selector is only attached to the rod/spring that goes back to the brake. Shouldn't there be something else attached because the speed selector isn't doing anything now other than pulling the brake in.
From the battery opening
Just for my own knowledge how does the speed selector vary the speed with only a belt drive? Does it ride in and out of the pulley slot depending on the tension like a snowmobile does? Does the speed selector move the pulley in and out to vary the speed?
Thanks again