Huskee(Tractor Supply Co.) model #44-9717-8/MTD #14AJ839 P131 transaxle ID

[totallymopar]

I have an early 90's(I believe) Huskee Lawn tractor,fairly rugged construction,20HP Twin cyl.engine(industrial/commercial) HUGE rear tires(on 13" rims!).It has a hydrostatic variable speed tranny,also rather large,1-1/2" axles 4-bolt rim mount, with cooling fins on it.Is there any way to identify who made the tranny,and where to find it? Also,I want to use it as a runner,when I'm not mowing with it.Top speed now is just under 10 MPH.I would like it to go 20,or a bit faster,but don't want to grenade the rear end.The rear axle pulley (3-1/4") is splined,and I plan to leave that alone.There is room to put a larger one on the front--I was thinking about 5"" up from the 3-1/2 on it now.With the stock pulleys,and the engine at 3600RPM max,the axle pulley is rotating at about 3877 max. RPM. If I change the engine pulley to 5",with engine at 3600RPM max,the tranny pulley will spin at around 5539 max rpm.Will the hydrostatic tranny in this be up to the speed increase? If not,what transmission would be recommended? The tractor is in very good condition,no leaks or wet spots on the transmission case,and runs well.

 

[StarTech]

Without the hydro gear model number having to the reference the main housing PN. Which indicates it is one of the four 618 model units. These are not design to operate above 3600 rpm input speeds. Severly damage can occur above this speed from cavitation.

 

[totallymopar]

Thanks for the info.Yes,you are right-it is a Hydrogear unit,model 618 0249.I researched the specs,and with a max 3600 RPM on the input shaft,and a 30.15 reduction ratio,the best I'm going to get,with the 21" tires is 7 MPH,without damaging the tranny.. After all it IS a Lawnmower. These guys they show on YouTube,going 20-25 MPH are shredding their rear ends-I know what cavitation can do.What about a rear-end out of a ATV-might that work?

 

[Tiger Small Engine]

Without the hydro gear model number having to the reference the main housing PN. Which indicates it is one of the four 618 model units. These are not design to operate above 3600 rpm input speeds. Severly damage can occur above this speed from cavitation.

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A larger pulley will result in slower speed, a smaller pulley faster speed, you got it backwards. Riding mowers stock usually travel forwards at about 5-6 mph. You said now it will go just under 10 mph (I would like to see that). At 10 mph it must be like riding a car without shocks. At 20 mph it would be like riding a bucking Bronco on steroids.

 

[StarTech]

A larger pulley will result in slower speed, a smaller pulley faster speed, you got it backwards. Riding mowers stock usually travel forwards at about 5-6 mph. You said now it will go just under 10 mph (I would like to see that). At 10 mph it must be like riding a car without shocks. At 20 mph it would be like riding a bucking Bronco on steroids.

Sorry but you got it backwards. Please re-read the OP initial post.

The OP was going to try to increase the engine pulley and leave the trans pulley alone. Say he makes the engine twice as large as the trans pulley that would be an 1 to 2 ratio; hence, if the engine pulley turns once the trans pulley turns twice. And if he made the engine half as large as the trans pulley the ratio would be 2 to 1. This 2 to 1 is something you see a lot when working on 4 cycle engines; Crankshaft to Camshaft.

A hydrostatic has it limits due its design. Now geared transaxle is a lot more forgiving but even they have their limits.

 

[bertsmobile1]

A larger pulley will result in slower speed, a smaller pulley faster speed, you got it backwards. Riding mowers stock usually travel forwards at about 5-6 mph. You said now it will go just under 10 mph (I would like to see that). At 10 mph it must be like riding a car without shocks. At 20 mph it would be like riding a bucking Bronco on steroids.

I did say the stack , ie engine pulley could be made larger
The standard trick s to invert the stack pulley as I first mentioned
This is phase 1 of conversion to racing mower so it goes just that bit faster , in fact usually about twice as fast
On a varidrive you need to fit a much larger front belt so best done to a Peerless/ Tecumseh or a Danna manual box

However your warning about the ride quality is quite correct
Racing mowers do not matter because they are usually running on a fairly flat trotting track
But in your yard it would be a totally different matter .

 

[totallymopar]

I think I need to clarify what I am doing.Because this is a large tractor,with 21-1/2" tires already on it,and the twin cylinder engine,I would be using this as dual-purpose machine.When using it as a mower,I leave the stock 3-1/2" drive/4-3/4 deck dual pulley on the engine,the 3-1/4" pulley on the rear, which gives me up to 7 mph.I did the math on it.Average engine speed at around 3300,giving me 3600 on the tranny pulley(the max rating)-- with the 30.15 reduction ratio of the tranny,,I am getting a rear axle speed of 119.4 RPM max.The 21-1/2 " tires go 5.66 feet for every rpm.5.66 x 119.4=675.82 feet per minute. That's 40549.25 feet in one hour.Which is 7.68 mph,in stock form-original pulleys,tires,everything. When i am not using it as a mower,I want to use it as a runner,like an ATV,but on a smooth surface.I live very close to town and can take it in on a back road, on a smooth surface.I was wanting to get it up to around 15-20 mph.But the ONLY way to make it go faster at all,is to swap out the hydro rear end with a gear drive with less reduction(I have a spare Spicer/Dana 4360 140ch 6-speed with a ratio of supposedly under 9:1,2000 rpm limit that's a bolt in),that would give me a top speed of 9.38 MPH,or a Peerless 820,8:1 ratio-also a bolt in,for a speed of 16 mph.Either that,or put larger tires on it.If I could go 7 ft/rpm,that would work out to 19 mph,or even 8 ft/rpm,which would be 22.3 mph-just what I need.This would require about a 30" dia. tire--all without overspinning the input shaft on the tranny.

 

[totallymopar]

I did say the stack , ie engine pulley could be made larger
The standard trick s to invert the stack pulley as I first mentioned
This is phase 1 of conversion to racing mower so it goes just that bit faster , in fact usually about twice as fast
On a varidrive you need to fit a much larger front belt so best done to a Peerless/ Tecumseh or a Danna manual box

However your warning about the ride quality is quite correct
Racing mowers do not matter because they are usually running on a fairly flat trotting track
But in your yard it would be a totally different matter .

You can't invert the pulley-the shaft bore on the small pulley(3-1/2") end is 1" for the engine with the keyway,whereas the large pulley(4-3/4) end is too large for the engine shaft with no keyway.And there is a washer welded inside the pulley shaft where the bolt holds the pulley assembly on the end of the engine shaft.I had another pulley assembly,where I cut the large pulley off and welded it onto the smaller one at the top,then slide it onto the engine shaft,and bolt it on.I wouldn't be driving it around the yard that fast-- but driving it as a runner at the higher speed,on a smooth surface road,then when mowing in the yard,go back to the stock pulley setup,for the low speed. A multi-purpose tractor.

 

[totallymopar]

A larger pulley will result in slower speed, a smaller pulley faster speed, you got it backwards. Riding mowers stock usually travel forwards at about 5-6 mph. You said now it will go just under 10 mph (I would like to see that). At 10 mph it must be like riding a car without shocks. At 20 mph it would be like riding a bucking Bronco on steroids.

Mine goes at a little over 7-1/2 mph,due to the large (21.5") and very wide rear tires.This is a commercial-duty tractor,made for large yards/acreages,so it was probably made to go faster,to cut mowing time. It has a 3-1/2" on the engine,and a 3-1/4" on the rear,stock.Usually,most mowers have the smaller pulley on the engine,and larger at the tranny--but not this one.Nothing had been changed-that's the way it was made.Even in my yard,which is hardly level at all,it does not do that badly-there are huge springs under the seat,and the front end is a massive casting,with front wheels almost as large as the rears on most other mowers.Only a Fordson is larger.

 

[totallymopar]

Sorry but you got it backwards. Please re-read the OP initial post.

The OP was going to try to increase the engine pulley and leave the trans pulley alone. Say he makes the engine twice as large as the trans pulley that would be an 1 to 2 ratio; hence, if the engine pulley turns once the trans pulley turns twice. And if he made the engine half as large as the trans pulley the ratio would be 2 to 1. This 2 to 1 is something you see a lot when working on 4 cycle engines; Crankshaft to Camshaft.

A hydrostatic has it limits due its design. Now geared transaxle is a lot more forgiving but even they have their limits.

The transaxle is limited to 3600 rpm until cavitation takes place,because it uses oil.A gear drive uses grease,but it is limited to 2000 RPM.Being gear drive means it is more durable,and grease is less subsceptible to cavitation than oil(but not immune).Hydros can spin faster at the input,but have a much higher ratio(30:1),while gears have less than half of the reduction(8-to-15:1),but can only spin less than 2/3rds the RPM of a hydro.So,whatever gains are made in RPM at the input shaft of a hydro(3600),are lost in the greater reduction(30:1),as compared to a gear.and whatever gains are made in the lower reduction ratio of a gear(8-15:1) are lost in the lower rpm of the input shaft(2000).Bottom line-transmissions used in lawn tractors are intended for low ground speeds for mowing,not for "transportation''.Nobody mows their lawn at 25 mph.But when you are financially strapped,and you have two lawn tractors sitting in your garage for free,and the price for a used ATV,or even a nonworking rusty go-Kart are through the roof--and your only vehicle is down with a shelled tranny at $2500 to replace it(even when you install it yourself)--and you HAVE to get groceries and items you NEED to function every day,and there are NO busses,taxis,Uber,GoGo Grandparent,family,friends,or ANYONE else to take you anywhere,then you get DESPERATELY creative to turn those lawn tractors into something that doesn't take an hour to get into town on.And they are a LOT cheaper on gas than my 6400-lb V8 Dodge Ram 250 Mark III conversion van.