# drive disengaging MTD PRO28



## 1654ROD (Jan 2, 2012)

I purchased a brand new MTD PRO28 unit, model#31AH64EG795 over the summer and have a problem with the drive on it that's driving me crazy. When depressing the drive lever, if I squeeze it all the way the drive seems to disengage and if I release it about 3/4" off the handle it will start to move again. I have adjusted the cable numerous times to no avail, friction disc and drive plate are clean.
The information in the manual goes no further than the basics. I just can't figure out why the throw of the lever affects the engagement of the friction disc once it's already made contact with the drive plate.
This is a brand new unit that hasn't even been used 20 minutes yet, I purchased it this past summer at a Sears outlet store. I haven't called Sears yet as past experiences with appliances haven't been very helpful, it will be my last resort.
Thanks in advance for any help!

Rod


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## Shryp (Jan 1, 2011)

Sounds like something isn't working right. Are you sure it was assembled correctly? Have you tried tipping it on the front housing and removing the bottom cover and watching what it does when the handle is pressed? These are pretty simple as all that happens is the handle pulls the wire and it pulls the plate that the wheel mounts to.


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## td5771 (Feb 21, 2011)

think of the lever as a clock hand ......as it approaches noon it gets closer and closer, but if you pull it past noon it will be fine then back away. 


basic explanantion without detail. if the levers/arms are set up a certain way they will act the same


I bet it is set too tight


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## Shryp (Jan 1, 2011)

Or maybe the levers are upside down or bent. Are there extra mounting holes in them?


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## 1654ROD (Jan 2, 2012)

Yes, I've had the bottom cover off and everything looks good. I considered the over-center theory on the adjustment and that's where I'm at now as I have loosened the ajustment up again. Loosening the cable seems to make the tension on the drive belt quite loose though and it slaps inside the cover, I can't seem to find a happy medium. I checked the tensioner and the range is limited with no adjustment, only spring tension. I suppose it's possibly the wrong belt?
The handles only go on one way and there is no addtional adjustment to the cable on the handle end.


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## Shryp (Jan 1, 2011)

Um, is your problem with the wheels or the blades?

You said drive so I was assuming the wheels.

But, the belt for the wheels has a spring loaded pulley and should always be tight. The drive wheels are controlled by the friction disc and plate moving and has nothing to do with the belt.

The augers or blades in the front are the ones who should have the belt get loose and slap around under the cover when not in use.


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## 1654ROD (Jan 2, 2012)

Problem is with the drive wheels and the belt doesn't have tension on it all the time, it only tightens up when depressing the drive handle. The belt only gets tighter when I adjust the cable for the friction disc. I've had the cover off so that I can physically see the belts and I do not see an alternate adjustment for the belt, should there be? There doesn't seem to be much of a throw on the tensionor, seems the range of motion is limited. I was wondering if there is slippage there but if it were slipping that badly I assume it would squeal or burn and I'm not getting either.


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## Shryp (Jan 1, 2011)

I am thinking there is something wrong with your setup. The belt the powers the wheels should have a spring on it and always be tight. The metal disc inside the bottom should always spin when the engine is running. When you push the drive lever down it should cause the small rubber wheel in the bottom cover to contact the spinning metal disc. The MTDs I have seen all move the spinning metal disc to the rubber friction wheel, but I did have a Toro that I swear worked the opposite.

Do you have any pictures of your machine? A picture of the belts from the top would be good and a picture of the bottom with the cover off.


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## 1654ROD (Jan 2, 2012)

The belt that powers the wheels does turn at all times, but definitely is not tight at all times and I'll have to pull the bottom cover again as I'm pretty sure the drive plate was turning too. It seems something is not right with the belt and tensioner so I'll investigate it further when I get home from work.

I've looked at the parts breakdown for the drive components and nothing really sticks out. The tensioner is only a spring loaded arm without adjustment and I don't see any other adjustment points for the drive belt. I have attached the parts breakdown for the drive.


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## Shryp (Jan 1, 2011)

Yea, I saw that parts diagram on searspartsdirect and partstree.com. It isn't very clear and I was hoping maybe you could get some pictures of the actual machine to help us out.


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## 1654ROD (Jan 2, 2012)

I'll try to get some photos to post when I get home from work tonight. Thanks for the help!


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## truder1400 (Oct 1, 2011)

1654ROD said:


> Problem is with the drive wheels and the belt doesn't have tension on it all the time, it only tightens up when depressing the drive handle.



If this is correct, it certainly sounds "wrong" to me...


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## Shryp (Jan 1, 2011)

truder1400 said:


> If this is correct, it certainly sounds "wrong" to me...


Reading the above post and his quote a second time has me thinking.

I wonder if some idiot attached the spring for the drive belt idler to the pivot shaft for the friction disc instead of the frame of the blower...
So now when you "engage" the friction wheel you also end up "dis-engaging" the drive belt.


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## 1654ROD (Jan 2, 2012)

Hi Guys, sorry I have been buried at work and not able to get back on this problem right away but after playing around with it some more, here is what I found.
There is a definite problem regarding the tensioner and drive belt for the drive. The tensioner has very little tension on it and doesn't move freely unless I loosen the mounting bolt, then it springs back and puts more tension on the belt. This is definitely part of the problem as ran it with the cover off and could see the belt slipping considerably and the amount of fibers from the belt covering everything seems to indicate the same. The belt sets way down in the pulley, so much so that it looks as though it should be a wider belt such as the one being used on the auger drive. 
Confident in my findings, I decided to break down and call Sears for a warranty repair as this machine is brand new and they'll be out next Tuesday. Talking with the rep it appears that there have been performance issues similar to this and a new belt and tensioner will be brought along on the call. Regarding the belt, there is in fact a wider one listed but it's usually used on a model with a different drive.
I'll let you know how it goes and thanks for all your input, it's much appreciated!


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## 1654ROD (Jan 2, 2012)

* UPDATE * FIXED * Just thought I would pass on that the problem has been solved. Replacing a weak and bound up tensioner assembly was the solution. We did hit a snag with the replacement belt they sent that was supposed to supercede the original. The new belt was so tight that it wouldn't fit around the tensioner, it was so tight that it had to be cut to get it back off. It was replaced with new belt same as the original and all was good. Took it for a little test run and it worked as it should.
Thanks again for all the suggestions and input in getting this problem resolved!


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