Toro LX425 Surging

Thanks for the input. I didn't change the upper drive belt. Will do that. The pulleys do have some wear. I'll take them off and take a light skim cut to clean them up, or replace them if their really bad.

I carefully inspected every pulley in the drive system. The only one that has any detectable wear was the the variable speed pulley. The wear was very minor and unfortunately the outer pulley half sheaves are welded to the shaft so I wasn't able to machine them.

Put everything together and no change. The tractor free wheels on downhill grades and the slipping gears/ratcheting sound is still there. For clarification the tractor pulls fine in forward and reverse on flat ground and uphill grades. I'm leaning towards the notion that the problem is in the differential even though the Toro dealer said it was OK. I'm stumped!!!
 
Here is a link to an exploded parts diagram of your transaxle.

TORO LX425 SINGLE SPEED TRANSMISSION ASSEMBLY

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Yep, that's it. The differential is riveted so I wasn't able to disassemble and inspect the internals. I was able to see that none of the gear teeth were bad. Wasn't able to determine how the axle shafts drive the spider gears (splines I assume) and that's where I think my problem is. What puzzles me is if one or both axle splines are bad then why does the tractor drive uphill without the differential slipping?
 
Is the shift lever adjust correctly so the transmission is fully in gear? I have a feeling that your shift dogs are jumping out of gear.
 
Is the shift lever adjust correctly so the transmission is fully in gear? I have a feeling that your shift dogs are jumping out of gear.


that was my thought too, DAN_IN_MN...or...wear on the bevel gears and /or clutch collar may be restricting the full movement of the shifting assy on the splined gear shaft.
 
that was my thought too, DAN_IN_MN...or...wear on the bevel gears and /or clutch collar may be restricting the full movement of the shifting assy on the splined gear shaft.

First of all thanks to you and others for helping me work through this. For what it's worth I adjusted the shift lever per the Toro maintenance manual, or at least I think I did. I'll play with the adjustment and see if it has any effect.

Thanks again.
 
First of all thanks to you and others for helping me work through this. For what it's worth I adjusted the shift lever per the Toro maintenance manual, or at least I think I did. I'll play with the adjustment and see if it has any effect.

Thanks again.


No problem Tom.

Have you tried kept your hand on the shift lever while it's acting up? You might be able to feel it jumping around if it is the shift dogs jumping in and out.

Does it do this only with a load on it or with it's own weight also?

How steep of an incline is it?

Do you think you may be pulling too much with it? (I don't have a clue as to what you've been pulling.)

How long have you owned this tractor?

Any recent change of drivers?

I have a similar tractor that I replaced the shift dogs with used ones. I know it still slips. It's been a few years and I don't remember at what state I left that project at. Just trying to let you know that others have been down this road.
 
No problem Tom.

Have you tried kept your hand on the shift lever while it's acting up? You might be able to feel it jumping around if it is the shift dogs jumping in and out.

Does it do this only with a load on it or with it's own weight also?

How steep of an incline is it?

Do you think you may be pulling too much with it? (I don't have a clue as to what you've been pulling.)

How long have you owned this tractor?

Any recent change of drivers?

I have a similar tractor that I replaced the shift dogs with used ones. I know it still slips. It's been a few years and I don't remember at what state I left that project at. Just trying to let you know that others have been down this road.

Good point about the shift lever. I'll play with it and see if anything changes.

To answer your questions; it slips with or without load; the incline varies from very mild to moderately steep; heaviest load I've pulled is about 200 lbs so I don't think I've been pulling too much weight; the tractor came with my house I bought about a year ago and has about 150 hours on it; I do most of the driving and try not to abuse it. I did inspect the forward/reverse gears and there was no wear marks on the gear teeth tips that would indicate slippage. The forward/reverse drive dogs didn't show signs of slippage either.

Thanks
 
SUCCESS!!!!!!!!!!!!!!!

I went back through the Toro shifter mechanism adjustment just to make sure I did it correctly, which I did. What I didn't notice was that the plastic shift detent insert on the fender wasn't allowing the shifter rod to fully engage the forward/reverse shaft in the forward position. Thanks to Goat Driver and DAN_IN_MN for staying with me on this and suggesting I manually hold the shifter in the forward position. Had I not done this I wouldn't have noticed the shifter wasn't fully engaged. The tractor doesn't free wheel on down hills anymore. Man am I glad this is over!

Thanks again Goat Driver an DAN_IN_MN.
 
SUCCESS!!!!!!!!!!!!!!!

I went back through the Toro shifter mechanism adjustment just to make sure I did it correctly, which I did. What I didn't notice was that the plastic shift detent insert on the fender wasn't allowing the shifter rod to fully engage the forward/reverse shaft in the forward position. Thanks to Goat Driver and DAN_IN_MN for staying with me on this and suggesting I manually hold the shifter in the forward position. Had I not done this I wouldn't have noticed the shifter wasn't fully engaged. The tractor doesn't free wheel on down hills anymore. Man am I glad this is over!

Thanks again Goat Driver an DAN_IN_MN.

You're welcome Tom, great to hear you got it figured out! :thumbsup:
 
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