# Yard Machine by MTD 638RL won't Move in any gear.



## bbowers132

Hi all!! I have a Yard Machine by MTD 638RL The Model number is 13A1762F029.
The mower won't move in any gear and it seems like something is either frozen or stuck. This happened a few years ago and I can't really remember all the details, but would like to try to get it fixed instead of just sending it to a scrap yard.
So if I could just get some suggestions as far as where to start troubleshooting it, would definitely be appreciated.
Thanks,
Bill


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## stickerpicker

Does this tractor have 7 speeds forward and 7 reverse? Is the pulley on top of the transaxle turning? Have you had a rear wheel off recently and lost the axle key?


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## bbowers132

Hi Stickerpicker. Thanks for the reply. It is a 6 speed "shift on the go" transmission. I haven't had any wheels off of it at any time. I will have to check on the pulley on top. right now the battery is dead because she has been sitting for a couple of years.
What is weird is that when I put it in neutral, I could sometimes rock it back and forth to get it to move some, and then it would just lock up again...


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## stickerpicker

Excuse my ignorance on this lawn tractor drive train but I couldn't find much about it by google.

The reason I ask about the 7 speeds I was attempting to determine if it has the infamous variable speed system which many have 7 speeds forward and 7 reverse with one lever to change from F to R.


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## bbowers132

Yeah, I tried Google also, and didn't find much. It does have a lever for Forward, Neutral, and Reverse and then another lever for Park and speeds 1 thru 6.


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## stickerpicker

Ok, so it apparently has the variable speed system that was designed to be shifted from 1-6 without using the clutch once the tractor is in motion. It is important it is operated that way and that info. is in the operator's manual.

It should have two motion belts. One from the engine upper pulley to the variable speed pulley and the second belt from the variable to the rear pulley above the transaxle. 

With both of these belts removed, or at least zero tension on them, the center portion of the variable pulley system should freely move on the shaft with finger pressure. This is what changes ratios and it is all controlled by spring tension of the idler pulleys both fore and aft.

The rear idler spring tension is determined at the factory and not adjustable but the front idler spring tension is determined by the operator by moving the speed control from 1-6. If that center part of the variable won't move free the system won't work in a favorable manner.


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## bbowers132

Thanks Stickerpicker, sounds like I'll be tearing this thing apart on Memorial Day... (That's my next day off from work)
Just an FYI, I found the manual and parts list on the MTD website.


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## stickerpicker

I hope a few things have changed since I repaired those. If there has been no change the deck is terrible to remove and install. Hope you can work on yours without removing it.


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## bbowers132

Yeah this is a 2008 or2009 unit, so I'm sure it isn't going to be easy to work on, but as the saying goes, I have more time than money! Lol.


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