Craftsman YT4000 - Slow uphill

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21
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Wisconsin
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I have a Craftsman YT4000 which has a Tuff Torq K46B Transmission Axle. I started noticing early this season that it would occasionally have trouble getting up hills. This would happen even while I was already moving fine up a relatively small incline (15-20 degrees, I would say). It is almost as if the gas isn't getting to the engine. It has gotten way worse now that it is colder, but has been getting worse for some time now over the season. The last 2 mowings (yesterday at 40F and then a week ago at 70F) were REAL slow going up hill. What I noticed was:
  • I could start on the incline fine, then would lose speed until it was essentially not moving.
  • While not moving I could bring the gas pedal back half way and it *may* move again
  • While not moving I could sometimes only let off the gas then press the gas slowly again to get it moving. Either way it always would eventually move.
So - I read through several threads here and on other websites. I watched several YouTube videos as well. I had come to the conclusion that it was the Transmission and I should remove it, drain it, and fill with 5W50 or 15W50 to solve the problem. I did just that with minimal problems. I took off the K46B, cleaned it up, pulled the fill plug, drained the sludgy old oil, re-filled with 15W50 to about 1 1/2 " below the fill hole, and moved the axle back and forth several times once the fill plug was put back in place. I then ran the mower in reverse and forward several times to purge. I mowed the backyard sideways so that the incline was slightly less than the usual mowing. It was a bit better than previous, but not by a whole lot. I still got stuck a few times and had to back off on the gas pedal to get moving again. So now I'm stuck wondering what else I can do frown It does have a new belt and I do not believe it's slipping as it is tight - and usually when it slows down I'm already at top speed on the same degree incline - so no extra load to cause slippage (or at least that is my thought). What should be my next task? I would assume something internal isn't quite working right, but don't really have the skills/tools to rebuild the transmission I don't think. Is there some other transmission that might fit this mower that is better/cheaper and can be fit without requiring a welder? Anyway - a little frustrated that I worked for quite a few hours and did not solve the problem frown Thanks in advance, Andy
 
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2,708
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USA
The belt between the engine and transmission could be slipping. With a hydrostatic drive, what you are calling the "gas pedal" actually controls the transmission. The engine runs at a constant speed controlled by the lever on the dash. The engine and blades do stay running steady, right? The problem is just that the machine won't move over the ground?
 
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21
Location
Wisconsin
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Originally Posted by mk378
The belt between the engine and transmission could be slipping. What you call the "gas pedal" actually controls the transmission. The engine runs at a constant speed controlled by the lever on the dash. The engine does stay running steady, right? Just that the machine won't move over the ground?
The engine does stay running steady, yes. I will have to check that belt, didn't even think of that frown I'll have to figure out belt size and hopefully have something local that fits. Appreciate that - I should have thought of that, just maybe too frustrated at the moment.
 
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3,992
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Central Maryland
Just went through exactly that, slow and couldn't climb hills, with my decade old Cub Cadet 1554. Hopefully it is your drive belt. Changing my transmission oil did nothing for me. I sold it for parts and bought a new Ariens.
 
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21
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Wisconsin
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I found a drive belt that should be pretty close. The specs from what I read are 1/2"x90" on the YT-4000, I picked up a belt that is 5/8"x90" that is for Craftsman/Poulon/Husqvarna. I will have to get under the tractor a bit later, but hoping this will be the fix.
Originally Posted by JHZR2
Is there a rubber clutch disc in there?
I will find out when I get back under there.
 
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21
Location
Wisconsin
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Originally Posted by CT8
Check the oil in the hydros.
Sorry - I have no idea what that means frown I'm just a regular average Joe who knows little about this stuff, but isn't afraid to get in and learn.
 
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47
Location
Eastern PA
Originally Posted by Covington
I found a drive belt that should be pretty close. The specs from what I read are 1/2"x90" on the YT-4000, I picked up a belt that is 5/8"x90" that is for Craftsman/Poulon/Husqvarna. I will have to get under the tractor a bit later, but hoping this will be the fix.
An oversize belt might make it worse (or introduce a new problem, if it wasn't the problem already). An oversize belt will run too high in the sheaves, and reduce the contact area between the belt and the sheaves, which will invite slippage. It may also overheat if the radius of the sheave is close to the minimum radius of the previous belt. The tensioner may not have enough adjustment range either. If the original belt was in fact the problem, and the oversize one somehow does work, I would not recommend it as a long-term fix. Or you will be fixing it again soon anyway. Learned my lesson on improper belt sizes the hard way.
 
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21
Location
Wisconsin
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Originally Posted by benjayman227
Originally Posted by Covington
I found a drive belt that should be pretty close. The specs from what I read are 1/2"x90" on the YT-4000, I picked up a belt that is 5/8"x90" that is for Craftsman/Poulon/Husqvarna. I will have to get under the tractor a bit later, but hoping this will be the fix.
An oversize belt might make it worse (or introduce a new problem, if it wasn't the problem already). An oversize belt will run too high in the sheaves, and reduce the contact area between the belt and the sheaves, which will invite slippage. It may also overheat if the radius of the sheave is close to the minimum radius of the previous belt. The tensioner may not have enough adjustment range either. If the original belt was in fact the problem, and the oversize one somehow does work, I would not recommend it as a long-term fix. Or you will be fixing it again soon anyway. Learned my lesson on improper belt sizes the hard way.
ok, thank you. I will make sure to find the exact size then. Will have to hit the store again or order online. I also noticed now, after you mentioned this, the part information I had from another site was innacurate - the part number I just found inside the hood is 130969, which is actually 0.5"x92.5". Back to the drawing board.
 
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47
Location
Eastern PA
I have noticed that many OE belts are goofy sizes (92.5 in your case), but you can only ever find even inch sizes in stores. I don't know why they do that, but it makes it all the more difficult to repair things.
 
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21
Location
Wisconsin
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Originally Posted by JTK
You said in your original post after changing the transaxle oil that the belt is new and tight. I'm confused..
yeah, because I didn't know what I was talking about wink I put on a new belt, but that was the belt for the deck. I honestly (showing my stupidity here) assumed it was the same belt. I put that one on beginning of summer when I changed oil and fuel filters and put on a new blade. (feel free to razz me as much as you want)
 
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21
Location
Wisconsin
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Originally Posted by benjayman227
I have noticed that many OE belts are goofy sizes (92.5 in your case), but you can only ever find even inch sizes in stores. I don't know why they do that, but it makes it all the more difficult to repair things.
I ended up returning that belt, googled Husqvarna, went to a local shop, and found the belt smile Husqvarna because this is actually their tractor and the belt is the same as their drive belt (on 42" deck models) except with a slightly different part number (532130969 vs 130969). I verified it was the same belt with the manager to be sure, but googling told me enough prior to going there. I feel much better about installing this belt, so definitely appreciate you catching me before I tried to install a belt that was not a perfect match.
 
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21
Location
Wisconsin
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ok, so I just finished changing the belt out. Mower now has NO problems going up hills! And, added benefit that I also know the transmission oil isn't sludgy and disgusting. Good learning experience! Now I have to figure out what part it was that fell off the mower last time out smile I don't see it anywhere on the parts list, so if you know what this is - let me know! (assuming engine somewhere since it was hot A.F. when I picked it up) [Linked Image]
 
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21
Location
Wisconsin
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ok. looks like bottom of muffler. I was thinking maybe exhaust, so I looked that up and saw it as part of the muffler system. Maybe I'll be replacing all that also.
 

JTK

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12,871
Location
Buffalo, NY
Yep. For sure the deflector for the exhaust. Should be OK without it, but I'd check what the exhaust is now blowing down onto without it in place. I think those are pop riveted in place, so you'd have to drill those out of the muffler and re-rivet. New exhaust systems are expensive for these.
 
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21
Location
Wisconsin
Thread starter
Originally Posted by JTK
Yep. For sure the deflector for the exhaust. Should be OK without it, but I'd check what the exhaust is now blowing down onto without it in place. I think those are pop riveted in place, so you'd have to drill those out of the muffler and re-rivet. New exhaust systems are expensive for these.
Thanks. I think I will just re-attach, then. No need to spend more smile
 
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