# Slowing MTD Ground Speed



## VaSnowfighter (Dec 20, 2021)

I thought I'd pass this modification along to other owners of MTD built machines. 

The machine was purchased last fall, a Craftsman 247-888531 (MTD 31AE558G099) that seemed a little too fast in first gear, to my liking. Since I was completely going through the machine, prior to putting it into service, I went ahead and did this modification.

To slow the machine, I replaced the 23 tooth sprockets, on the drive axle, with 30 tooth sprockets, I found for a cheep price on Ebay. Doing the calculations, this gives me a speed reduction of 23.3%. The part number for the 30 tooth sprocket is 91304009. I also removed the 4.80-8 tires, and swapped in the 16-6.5-8 tires from my straight axle MTD, since both sets are the same height.

I used it a few weeks ago on a 7 inch snowfall, with 3/4 to 1 inch of frozen sleet on top of the snow. It worked very well, as I could creep along in 1st gear when needed. When I tried to move at a more normal speed, the machine would tend to get on top of the frozen sleet. Creeping along, it acted like an icebreaker, for lack of a better description. It sounded like it was throwing gravel, due to the ice. I really like the slow gearing for the end of driveway, and clearing what the snowplow left in front of the mailbox. Reverse 2, in my opinion, still operates at a decent speed. 

Anyway, just passing this along to others who may be interested.

Attached are a couple of photos, showing the installation.


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## crazzywolfie (Jun 2, 2014)

if you want to try making it even slower you could try swapping out the drive plate to a drive plate assembly off a a single shaft machine. you will likely need a longer belt if you do but it should make the machine a lot slower since the pulley on the single shaft drive plates are much larger than the dual shaft ones.


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## VaSnowfighter (Dec 20, 2021)

crazzywolfie said:


> if you want to try making it even slower you could try swapping out the drive plate to a drive plate assembly off a a single shaft machine. you will likely need a longer belt if you do but it should make the machine a lot slower since the pulley on the single shaft drive plates are much larger than the dual shaft ones.


I may try that in the future on the Craftsman. I installed an 8 inch drive plate several years ago in my straight axle MTD machine, replacing the 6 3/4 inch (6 inch effective pulley size) drive plate. Made a big difference in slowing the ground speed. The calculations for the 8 inch drive plate give a 25% speed reduction. It does require the use of a longer belt.


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