Vari drive with 5 speed transaxle

Hay people,
Got a new project I need to do. I need a better/stronger riding mower for cutting my grass. Yes, I know, cutting grass. Not you people normal topic on this forum, LOL. But the running gear might interest you all. It's been mentioned by me on a couple of posts in the forum. I have a riding mower with a vari drive system and I removed the f/n/r and put in a 6 speed gear box. It has 30 forward gears and 6 reverse gears. YES, they all work. It even has a pulley swap on the transaxle too. I can do a gps run on it for you all because of the pulley swap but it does go any faster for some reason, goes maybe 1 or 2 mph faster then the other riding mower I will be using for parts with a regular vari drive system. I built the red one to go real slow.

I got the red riding mower from a guy I did work for maybe 15 years ago. Had a 10 hp techumsa that didn't run right. My brother in-law gave me a brand new 8 hp pull start and I put it in so I could cut my grass with it. Got a couple more riding mowers that I stripped for parts and came up with a 6 speed transaxle. took me a year or 2 to get the nerve to tear into the red one and replace the f/n/r with the 6 speed but got it in. Bolted right up, figured out the belts and got it going good enough to cut the grass. The reason I put the 6 speed in was the 8 hp engine was not strong enough. I had to ride the clutch to slow it down enough to not stall the motor to cut the grass when it got higher then 6 inches. After I got it going with the 6 speed I didn't have 1st in the vari drive because I had to use a 1/2 inch belt instead of the 5/8 belt. Then I got another mower for parts and had the 5/8 belt I needed to get mine going right. I finally got all the gears working and it worked great, finally. I cut my grass for another 2 years with it.

The same guy that gave me the red one, gave me the green one. Probably 8 years later by now. Got the green one going and just parked the red one. The green one has a vari drive system too, plus 4 wheel steer, plus a bag setup. Frame was in better shape and electrical all worked with key start. Just had to switch out the motor. I put a 12 hp flattie in it. Well back to the same problem with the motor not being strong enough and riding the clutch.

I'm thinking about combining the 2 someway to get all the good stuff on one riding mower. I'll just be talking about the driveline though in this thread since some of you was interested in doing this setup.

First 2 picks are for the belts. It has a double pulley tensioner on the second belt and added another idler pulley to get it working right. Can't remember if the other belt has a double pulley clutch though. You all will see later when I tear into it.




The vari drive 5 speed shifter for the belts


front view


The rod with the long bolt and is under the seat is how I shift the 6 speed transaxle with the reverse gear


Both mowers side by side that will be used


Rear view showing the shifter under the seat and a look see of the transaxle


First things first, I need to get the green one running to cut my grass. Just routine maintenance. In the mean time I will be tearing into the red one to see what the damage is. I don't know which frame I will be using but it will definitely have the red hood and grill on the finished mower along with the yellow seat. I might put the bagger setup on the finished mower maybe. As for the 4 wheel steer, I don't know how good a shape it is in to reuse, might need new U-joints, but that part I really don't need but would be nice to have. And last but not least, will have the vari drive with the 6 speed transaxle and I most likely will put the big pulley back on the transaxle to go even slower, If I can find it in my basement, which is what I really need. My foot gets tired riding the clutch all the time and probably is burning the belt up to. After I get this thing built, I have a couple Briggs oppy's, I will be building one up for this in a few years. Priority will be getting it up and running ASAP with the 12 hp Briggs flattie for now.

Any questions, feel free to ask them. I might make a video or 2 but for the most part will be mainly pics.

Hay People,
Got part of my grass cut. The green riding mower started right up after charging the battery, Cool. Even with last year's gas, lol. I'm not going to touch the motor when I put it in the red one except for an oil change which will be done before I do my next cut.

Kinda have to because the previous owner put a water faucet for the oil drain. Some how the faucet nob turned a little and all the oil drained onto the dirt. Funny, never happened before. I think that tarp grabbed the nob and turned it during the last rain storm. That's OK, needed changed anyways.

Here it is all in pieces after the end of the day. The only thing I didn't take apart was the steering.


No worries, took plenty of pics to put it back together.

Before I start with the teardown part, I just want to mention that when I last worked on this mower.It had to have been around 5 years ago. I had it outside for 3 years in the rain and snow before I put it in my shed for storage. All the bolts I removed and reused got antiseize on them. The nickle antiseize. For those of you who don't use it or never heard of it, GO GET SOME!! It makes a world of difference. I tore this whole thing down and not one part with the antiseize was stuck or seized up. From the crank pulley to the rims, came right off. The nickle antiseize is for body bolts and no heat areas, while the copper antiseize can be used for the same but is also for high temp areas like spark plugs and exhaust bolts. Just look at the pic on the threads.


OK, on this thread I plan to show how the vari drive system works, pulley dimensions, and belt and clutch adjustment spots to do maintenance. But not tonight, it's 4 am and I got a gearbox to change in the morning sometime on my Jeep. Later People.

Fascinating project. Iv e always wanted to do something like this with the vari drive and gearbox. I'd like you to detail the whole build in this thread, I'm interested to see it take shape.

Sure think. I am curios on the ratio's of the belts in the different gears for the vari drive. They go from underdrive to overdrive between engine and transaxle. I have other plans for this setup on another project being planned.

Hay People,
Forgot a pic last post so here it is. The reason why I didn't put some gas in it and see if it still ran for a GPS speed. Found it pulling the motor. A little Bee's nest in the carb.


OK, on to the pulleys. These are pulley sizes on motor, vari drive pulley, and transaxle input pulley. For the Vary drive setup on my red mower has 5 gears on the shifter. The green mower has 7 on the shift selector but the vari drive pulley is the same diameter. Pretty much the same size on other mowers also, I have 2 other setups too in my basement which are same diameters. So, knowing they are pretty much the same diameter I will be focusing on the lowest gear on my red mower which is 1st gear and the highest gear on my red mower which is 5th gear. Which means the math will also apply to my green mower too with 1st gear and 7th gear but the numbers will be different due to pulley sizes. Now remember, this is only on the belts from motor pulley to vari drive then to transaxle input pulley. THIS WILL HAVE NOTHING TO DO WITH TRANSAXLE INSIDE GEARING.

Onto the pics.
Motor pulley is stock size and belt fits inside a little, but to make the math easy, the pulley diameter is 3 inches.


Point of reference when talking about the vari drive pulley, it has 2 belts on it that change size so it is a double pulley by design, and power goes into and out of this pulley. Which means motor power goes into one groove of the variable double pulley, and power goes out of the other groove of the variable double pulley. Doesn't matter which groove the power goes in or comes out since they are the same outer diameter. Which pulley is selected is picked by chassis design and belt alignment by the engineers.
With this in mind......
 For the groove with the belt where the motor puts power into the vari drive pulley, I will refer to this groove as VARI DRIVE INPUT.
 For the groove with the belt where the vari drive power comes out and goes to the input of the transaxle, I will refer to this groove as VARI DRIVE OUTPUT.
Moving on................

This pic is of vari drive input in 1st gear. Belt has a diameter of 5 inches.


This pic is of vari drive output in 1st gear. belt has diameter of 2 1/4 inches or 2.25 inches


This pic is of the transaxle input pulley. Ignore the chain sprocket welded onto it, it was a part from another project that didn't work. Sorry about the blurriness too. So the pulley on the transaxle input is 4 1/2 inches or 4.5 inches.


OK, now there is enough to do some math now, yes math,,,,, I know.
To do the math, need ratios of the individual belts. There are 2 belts, motor belt and transaxle belt, then multiply those 2 numbers to get the final ratio going into the transaxle input shaft. OH BOY!!

To know where to start is to follow the power. The motor makes the power and puts the power into the vari drive input by the motor belt. ENGINE PULLEY-3 INCHES, VARI DRIVE INPUT IS 5 INCHES= 5 divided by 3  makes ratio 1.6

Power goes out the vari drive output to transaxle by the transaxle belt. VARI DRIVE OUTPUT-2.25 INCHES, TRANSAXLE PULLEY-4.5= 4.5 DIVIDE BY 2.25 makes ratio 2

Now multiply the 2 ratios from the belts to come up with the final ratio going to the transaxle input shaft.
1.6 X 2 = 3.2 ratio. For the vari drive shifter setting for 1st gear I get a ratio of 3.2 , so motor spins 3.2 times for 1 time of transaxle input shaft rotation on my red mower.

I'll make this easier to look at so you all can play with the numbers. Just remember that the VARI DRIVE PULLEY SIZES STAY THE SAME. You will only change the motor pulley and transaxle pulley. This will be for 1st gear only for the vari drive.

    Motor belt               X            transaxle belt              = Final ratio     
(3 divide by  5=  1.6 )   X   (2.25 divide by 4.5 =  2  )  =  3.2
              The 5 and 2.25 stay the same
Only change the 3 and 4.5 with your pulley sizes

For a more traditional setup with just a motor and transaxle (no vari drive setup), The motor would have a 3 inch pulley and transaxle would have a 9.6 inch pulley and would be that every gear of the transaxle. For comparison purposes.

OK, who wants to do the work for 5th gear on the vari drive for my red mower. The vari drive input and output is reversed for pulley sizes. This is where it gets interesting.  LOL............ Come to think of it, looking at the setup, I think there was pulley slippage going on after figuring out the answer.  I'll let this fester for a couple days to see who is paying attention, then I'll move on.

Is that a Briggs in the red mower? Looking forward to seeing more!

Why yes it is a Briggs & Stratton. I got it new from my brother-in-law, 8 hp, pull start only. Only thing wrong with it is there is a hole in the top of the gas tank and air cleaner is missing. It's just not strong enough.

Hay People,
I mentioned the oil drain on the green mower being opened and the oil being drained onto the ground. Well, I got home yesterday from work and forgot about it having no oil in it. OOPS!! Started it up and started cutting the grass. Well, went about 50 feet and the engine stalled, not in a good way either. Engine is hard to turn now but still can turn atleast. Probably burnt up the starter too, trying to start it up while it was dragging too. Looks like this thread will include an engine build too. If the motor is unsavable I have a 10 hp Techumsa to put in it till I get around rebuilding an oppey for it.

I'm thinking the aluminum from the piston seized onto the cylinder wall. This is fixable. I guess we will see if it will start up this weekend so I can finish cutting the grass this time and hopefully 1 more time. Then probably a teardown of the green mower for the parts to replace stuff on the red one. And yes, I will be rebuilding the red frame for reuse for the buildup, it's not too bad from rust. Most likely be painting and and a big maybe on undercoating the frame for longevity.

Still no takers on the math for high gear ratio for the red mower? I'll show the math Friday night,

Hay People,

OK, I'll do the math for 5th gear for the vari drive for the red mower. Now remember that I did do a pulley swap on the transaxle when I put in the 6 speed transaxle. This will effect the numbers from a stock riding mower ofcourse. Onto the math.

(3 divide 2.25) X (5 divide 4.5) = 0.675    OK, I'll explain where I got the numbers.

For high gear on the vari drive, the input and the output pulley sizes are reversed. The vari drive double pulley is pulled towards the back of the mower which makes the motor belt go from the outside of the pulley groove forced into the groove and in turn makes a smaller pulley. while this is happening, the center pulley wall slides over to the other groove and squeezes the belt out of the groove and makes the pulley bigger. The end result of all this happenings is that the vari drive pulley input, in high gear is now 2.25 inches in diameter, and the vari drive output pulley is now 5 inches in diameter.  SO........ I'll go through the numbers from left to right explaining them....
 3= motor pulley size
 2.25= vari drive input pulley size
 5= vari drive output pulley size
 4.5= transaxle pulley size
 0.675= This is the ratio for the transaxle. Which means for every 1 turn of the motor, the transaxle input shaft turns 0.675 of one turn and is over driven.

A little comparison is in order to a more traditional riding mower. It would be a riding mower with a 6 inch pulley on the motor and a 4 inch pulley on the transaxle or with an 8 inch pulley on the motor and a 5.5 inch pulley on the transaxle. Roughly put.

Lets do both now(low gear & high gear), LOL. This comparison is on the belts only. So In first gear on the vari drive shifter on my red mower would be the same as a riding mower with a 3 inch motor pulley and a transaxle pulley of roughly 9.5 inches big. And when I put the vari drive shifter into 5th gear on my red mower, it would be the same as having an 8 inch pulley on the motor and a 5.5 inch pulley on the transaxle.  NOW THAT'S COOL!!! I guess I had a LOT of belt slippage because it seemed it was only a little quicker then my green mower. I think this because I just put it together good enough to just cut the grass. I could of done a better job on the belts but had no money or time when I did this mod. Now I got time and a little money, I'll be doing it right this time.


As you can tell by what I said about the slippage in the belts, these setups are prone to it. Probably got to do with the sizes of the vari drive pulleys, the smallest size being 2.25 inches or 2 1/4 inches in size. The belts have a hard time wrapping around the pulleys since they are pretty wide which makes them stiff too. There's ways around that if you know how to deal with it.

Any thoughts on this People?

Did you get the green mower running again? That is pretty fast in top gear, especially when you got a nice low first gear.

MatthewD wrote:

Did you get the green mower running again? That is pretty fast in top gear, especially when you got a nice low first gear.

Yes, I got the green riding mower going. It wasn't what I thought, the motor not having oil. Even though the motor didn't have oil, it was a combo of 3 other things that made the motor quit. I'll post in a day or 2, but this combo saved the motor and is still running strong now, with oil in it, LOL. I'll still tear down the motor to take a peak at it and maybe port out the runners, can't seem to resist that one, LOL.

Hay People,

Before I get to the regular stuff, a little visual on my yard I'll be cutting with this mower. I got dogs, don't ask how many but they been busy digging holes, big holes, LOL.
You can hardly tell but the hole is atleast a foot deep.


I might need bigger tires, LOL.


OK, I thought the motor in the green mower seized up from no oil, WRONG. Pulled the head and cylinder was fine. I was spinning the fan on top and felt as if it was dragging, hard to turn. Turned out it was the starter gear got stuck on the end of the bendix and when hand turning the flywheel I was turning the starter also that was still engaged.



So, a starter rebuild is in order on the next post. I fixed the starter and popped it back on. Put motor's head back on and still no fire. Dead ignition. Disconnected the kill wire, nothing. Pulled the tin cover and coil was too far away so I moved it closer. Finally got spark. Put back together and still no fire. Sprayed some brake clean in the carb, cranked it and got a fire. Sprayed some more and motor finally started. Ran like crap, backfiring a couple times, but still running. Smoothed out and ran great. Water in gas. So these 3 things going wrong saved the motor, if I would have kept cutting the grass, I would have seized the engine for sure.

Next post is rebuilding starter with tips how the professionals do it.

Hay People,
This post I will share tips on rebuilding starters. I won't be doing a step by step for the obvious stuff, like unbolting the unit from motor, taking it apart, stuff like that. It would take too long and is straight forward. These will be tips from a professional who does this for a living (20+ years) ME. Part of what I do at my full time job is rebuilding, modifying, custom finishes, and designing starters for, well mainly old school V8 engines and then MASS produce them. I use the term professional loosely, LOL, because it took me over 10 minutes with a screw driver and pliers just to get the clip off the armature shaft that holds the gear on. Good thing my boss didn't see that or he would be making fun and pointing at me along with him telling me tank jokes about me, LOL. OK pressing forward........

Tearing the starter apart, 2 bolts on backplate holds the whole thing together, remove them. Doesn't matter how the backplate goes back on but can go on either 2 ways, remove the backplate. You see the brush holder, pull it out, the brushes shoot out doing this so don't loose the springs. Before removing motor housing, mark housing in reference to frontplate for clock position, then pull the housing off. Remove the clip that holds on bendix that holds the gear on, remove clip holder, spring, gear, bendix housing. Pull the armature out of front plate. Starter is completely apart now.

On my starter, one of the magnets moved out of place towards the brush holder which made the starter weak to turn the motor over. Plus no grease on the bendix for the gear which is probably why it got stuck.




Here are the magnets, Note that on one side, the magnets have a marking and on the other side, they don't. It matters how they go into the housing, you know that north south thing. The white marks also indicate top and bottom. Tabs hold the magnets in place and in my case, one of the tabs bent under the magnet to where the magnet moved up past it. I remove both magnets to expose the housing which is bare metal and rusting.



I clean the rust out of the housing. Then I paint the area under the magnets to keep them from rusting again. The rust will build up and push the magnets into the armature, not good. After painting, I put the magnets back in.



Yes this pic again, forgot to take one of the armature. The Part of the armature the brushes ride on, sand it to clean the copper (ofcourse). If any grease gets on this part the grease will burn into goo and will make the starter drag so should be clean and oil free. On some armatures there are slots between the copper strips where the brushes ride on, clean these slots out because that dirt is copper dust from the brushes and will make the electricity jump over to the next slot before it needs too. The slots are there to control the copper dust, to trap it there till the next rebuild. Other armatures are filled with insulating material and no maintenance is needed. Do these 2 steps in the order I said. You don't want to clean the slots then sand the copper straps only to fill the slots back up. Next is to blow out the armature wires with compressed air. The copper dust is inside the wiring and will short out the armature from inside those wires if buildup of this dust gets real bad. You'll be amazed on how much copper dust is in there.  


This pic is for reference purposes. Note brush wires with covering (+ wires) and bare wires (- wires). The - wire clips are held in place with tabs on brush holder. + wires go to post for battery wire. Brushes are still good. Alot of copper dust covering the plastic too.

Close up of brush holder that is dirty. That copper dust will short out here there and everywhere. Clean brush holder so it is dry, oil free and dirt free. Make sure brushes move freely in the holder slots.


Brush holder cleaned and put back together. And clean the springs too, clean and dry.


Getting the brush holder back on the motor with the brushes set will be a pain. Figured out how to make a brush holder tool to set the brushes by holding them in the holder so I can just set it in place and pull the tool out and the brushes spring into place. Need 2 of these tools.


Made the 2 tools from a paper clip. Each tool holds 2 brushes in, in the brush holder. Just put the spring in and push the brush in and slide the tool in the slot. That simple.


Here you can see how it holds the brushes in place. With the brushes set, you are able to move the wires to where they are not touching anything to short out like a bolt or housing. So predict where the bolts will be going through this part and how this part is set on the housing. The wires brush wires move very little just so you know.


Now just set it in place and pull the 2 tools out, taking note the sound of the brushes hitting the armature. Move the armature side to side to see that the brushes follow and never loose contact with the armature.


The thru bolts. Just a bolt right? No! They pass through the brush holder next to wires. These wires if they are just laying on the bolt with covering on the wire, will burn thru the covering and short the starter. An extra layer of covering is in order here. Electrical tape works great for this among other things that is harder to get a hold of.
Cover the bolt shank with the electrical tape going long ways from the bolt head down. Put in starter housing and tighten.


Ever wonder if you are using the right grease? You use white lithium grease for starters. Because in cold temperatures will not get hard and jam up the starter bendix. And has a low temp rating to where the bushing gets just a little warm, the grease will turn to a liquid and the heat will pull in the liquid grease to cool the bushing. To grease the armature, The bushing is in a holder, put some grease in the bushing so when you set it on the shaft the grease will get pushed to the back, away from the brushes for the backplate. When the grease heats up, will get drawn into the bushing. If you lube the shaft of the armature, the grease will get pushed onto the brushes and burn onto the copper strips when running so put the grease in the backplate bushing only. the front of the armature where the gear is just grease up the shaft of the armature and you are good. Grease up bendix is just brushing it on the spline and putting the gear on.


That's it, Later.

Excellent write-up! I've had to take apart 2 of my starters. I only missed 2 of your steps in my process. (paint inside and electrical tape on bolts) I will remember and do that next time!

Thank you. I actually forgot 2 things in post, being half asleep writing it up. So here there are.
The armature, tape up the part where the brushes  ride on and paint the stacks. Thats the part that is the electro magnets. This part (the stacks) is raw steel, if gets wet will rust and expand, expand into the wiring of the armature and short it out. So soak the stacks with paint to make waterproof. Paint is nonconductive. I do this on marine starters to give them a fighting chance, lol. Water can also short out the wiring of the armature too, so don't be shy with the paint. Dont worry, the paint will not make the armature run hotter.

Second is, the backplate and frontplate, you can silicone these to the center field housing (motor housing), to make the motor as waterproof as posible. The electric motor can be air tight as posible. Comes in handy when crossing a creek, lol.

Hay People,
Been busy doing other things, but here is another post on this project. Been going real slow on it. Good thing I didn't tear down the green mower, and still running strong, LOL.

OK, I figure I would take apart the transaxle for a quick looksee, because it was hard to shift sometimes. Especially when there was pressure on the driveline, don't know really if that is normal, even when the clutch was pushed in. Maybe it was just rusty inside and a good cleaning would help. Brakes always rusted up and locked the transaxle which was annoying too. After looking at the guts, found out it was a 5 speed transaxle so I changed the post title......

It is a Foote transaxle. Any info on how good it is would be appreciated, and the sticker of the red riding mower, Thanks... Looks to be an "86" I think.



Here's the trans setup showing how I did the shifter and the double pulley tensioner. I have to say this crusty setup didn't work to good because it was a rushed job making it work, but did get the job done. I kept everything on the trans for an easy and quick install. The shifter linkage was a little short getting to 5th gear and jammed up, which is why I thought it was a 6 speed when actually it was jamming up in 5th gear. The double pulley worked ok for moving but the belt being 5/8 inch wide was really stiff and evidently was probably slipping on the trans belt. The bracket for the tensioner was the trans bracket mount bent up to mount the pulleys on. The other side was used to secure the front of trans.



Looking at the guts, I don't think it looks bad. Grease is a little dirty but other then that it looks OK. Reverse chain is loose but that's a gear that is rarely used so I'll be leaving it alone for reuse. Pulled everything out and apart for inspection. All bushings, gears, shafts, input bearings, pinion gearing, all looks good. Only problem I seen was the shift keys had some dinks in them. Cleaned up the shift keys on a grinder and good to go.





Put it back together. Kept the old grease in it since it's still good, plus added some oil to it, so it will dilute the grease  and get into the hard to reach spots. Put sealant around the perimeter of the case and put the case back together. Kept the diff open ofcourse for easy turning, LOL.


OK. I'm doing a pulley swap. How slow can you go!! LOL. I bet you People are like "NO, that ain't right", LOL. Found an 8.5 inch pulley to go on the transaxle. The f/n/r originally had a 6 inch, I found it looking for this one. The f/n/r is actually pretty strong since I put it in the riding mower I do plowing with after I broke the 3 speed in it pulling my Escort. That build will be later, still collecting parts for that one. Back to the pulley. Pretty big and I have to redo some of the linkage for the vari-drive to get it to work. Plus the pulley is for a 1/2 belt, not a 5/8 belt.


OK, at this point I have the main frame put back together, but haven't decided if I'm going to use it because it is pretty rusted, weak and bends easy. Not the best combo for something I want to last for a long time. I bolted in the transaxle for mock up with the vari-drive pulley and fitted the 5/8 belt on. The belt fits only a 1/4 of the way into the trans pulley. I spin it and the belt pops off with ease, not good. The belt needs to fit all the way into the groove to stay on, even with a miss alignment. The belt alignment part will be in another post. I want to use this pulley so a modification is in order. I need to open up the groove so the 5/8 belt will go in deeper. I grab my breaker bar and set it in the groove with the pulley on a block of wood. Then I hammer the breaker bar into the groove while rolling it back and forth using light hits to make the bends little per hit of the hammer to open the groove. The wood keeps the pulley from getting dented and solid enough to hold the pulley for a solid hit. I also marked the pulley in sections to make it easier to see to keep track of the opening up of the groove.


Worked pretty good. Should be pretty smooth running on the belt. I would see pulleys at Tractor Supply but would be for 1/2 belts only. Had no clue on where to find a pulley for a 5/8 inch belt this big. And I really didn't want to cut the hubs out and hope I would center it in the original pulley I found. This way saved time and money.


Here it is. Put back together with the new pulley on it. Redid the shifter linkage rod, made it a tad longer and shifts way better with no binding going into 5th gear. I'll be mounting the belt tensioner onto the frame most likely because I broke a bolt in the trans pulling the bracket off and then snapped a bit in it drilling it out. And cleaned up the break so it would work right.



More to come...........

Hay People,
Math time!! I'm curious as to the ratios inside the trans, just to make sure I'm right. Would suck big time doing all this work and the outcome be the same as an f/n/r transaxle in it. When I had the transaxle apart, I counted all the gears teeth. YES, it was tedious work but needed to be done, and made notes for it too. I then took a pic and put the #'s in their spots.



Doing the math.......
Each set of gears, I need to find the ratio for them by division. Then multiple the ratios in its path to the axle. Simple enough, just need to keep the path in mind. I'll only be doing 1st gear and 5th gear. Don't really need to know the ratios for the in between gears.

KEEP IN MIND THAT THIS IS INSIDE THE TRANSAXLE GEAR RATIOS IN THIS POST.

1st gear path with final ratio, from input shaft to axle= 61.505 to 1  
 So that is- the transaxle being in 1st gear, the input shaft is spinning 61.505 times for every 1 rotation of the axle. WOW!!!


5th gear path with final ratio, from input shaft to axle= 12.209 to 1
 So that is- the transaxle being in 5th gear, the input shaft is spinning 12.209 times for every 1 rotation of the axle.

Here is the math. There are 4 sets of gears to find the individual ratio for. Then multiply the 4 individual ratios to come up with the final ratio from input shaft to axle.
The first set of gears are the input shaft (sorry, no pic)-14, and the beveled gear-42.    42~14=3
The second set of gears, is 1st gear of the transaxle, input horizontal shaft-12, and output shaft to pinion gearing-37.   37~12=3.083
The third set of gears, which is the first set of pinion gearing, after the shifter linkage, on the output shaft after the shift linkage-14, mid pinion gear-35.   35~14=2.5
The fourth set of gears, the bullgear and the other side of the mid pinion gear. Mid pinion gear-12, bullgear-32.    32~12=2.66

Now, multiply the 4 individual ratios
1st gear- 3x3.083x2.5x2.66=61.505
5th gear- 3x0.612x2.5x2.66=12.209

Anybody Know the ratio of an f/n/r?

Hay People,
I'll do the final drive ratios in this post. This will be from Engine pulley to axle. Meaning everything in between. I'll keep it short and just show the answers with a description. Plus a little comparison to a more traditional driveline setup.

This is with the vary-drive in 1st gear and transaxle in 1st gear. So, low-low gear. Ratio= 370.998 to 1

This is with the vari-drive in 5th gear and transaxle in 5th gear. So, high-high gear. Ratio= 15.566 to 1

This is with the vari-drive in 5th gear and transaxle in 1st gear. So, high-low gear. Ratio= 78.418 to 1

This is with the vari-drive in 1st gear and transaxle in 5th gear. So, low-high gear. Ratio= 73.644 to 1




OK, This will be the comparison to a traditional setup of an engine pulley being 3 inches and a transaxle pulley being 8.5, and same transaxle.

1st gear. Ratio= 174.26 to 1

5th gear. Ratio= 34.55 to 1


I'm liking these numbers. Looks like I'm doing good and will do what I think it will do. Cool.

You are making my brain hurt! Good job with all that figuring.

I think I'm getting all this

I remember reading somewhere on here that the fnrs were 21:1.

Good memory Rich...
https://www.atltf.com/t2794p15-anyone-lock-a-mtd-fnr

Thanks for the info Rich. I'll do the math later tonight maybe. I also decided to use the green mower for the finish mower. No sence on rebuilding a chassis that has too much rust and is week. Already signs of cracks in it. The green mower also has a rebuilt deck on it, since it will be used for cutting grass after all. But the 4 wheel steer won't be hooked back up.

Looks like I'll be going through the steps fresh all over again.

Stay tuned.....

The numbers for a 633 are:
low
1st 60:1
2nd 38:1
3rd 24:1
high
1st 12:1
2nd 8:1
3rd 4:1

I don't remember the pulley sizes, but I would guess 3" on motor and 7" on the tx. Multiply the ratios by 2.33 to compare to what you came up with. Stock top speed with 23" tires and 3600rpm will be around 6mph. That will make your application with 18" tires super slow in low/low and probably top out around 3 in hi/hi if I guessed right

mightyraze wrote:

Good memory Rich...
https://www.atltf.com/t2794p15-anyone-lock-a-mtd-fnr

Thanks for the link Mightyraze.

Hay People,
Fun with numbers.....

OK, first thing. No guessing on the f/n/r pulley size. I actually just got up, went down in my basement and measured the f/n/r original pulley and is 8 inches.


I'll do the original MTD driveline setup now with the vari-drive and f/n/r for 1st and 5th gear.

1st gear= engine belt ratio-1.6, transaxle belt ratio=3.55, total ratio from engine to transaxle=5.68
  5.68 ratio X 21 transaxle ratio=  119.28 to 1 total ratio from engine to axle shaft.

5th gear= engine belt ratio-.75, transaxle belt ratio=1.6, total ratio from engine to transaxle= 1.2
  1.2 ratio X 21 transaxle ratio= 25.2 to 1 total ratio from engine to axle shaft.

OK, A comparison between the stock setup and the modified setup of ratios from engine to axle shaft.

  Stock/Modified
119.28 to 1 - 370.998 to 1- 1st gear and low/low
25.2 to 1 - 15.556 to 1 - 5th gear and high/high

Alright, I'm good then.
I think a turtle can beat me in a race in low/low. Couldn't even imagine the speed I'll be doing.


Now my modified setup compared to a traditional setup explained in pulley sizes. I figure you all would relate to this comparison better then the ratio figures. To get a better idea on the speeds through you all's experience.

-My low/low gear, if it was a traditional mower would be the same as-
engine pulley-3 inch, transaxle pulley-17.76 inches with a regular 5 speed transaxle.
-My high/high gear, if it was a traditional mower would be the same as-
engine pulley-5 inch, transaxle pulley- 8.5 inches with a regular 5 speed transaxle.

Not bad, not bad at all. I'll be using the green riding mower for the frame. It has it's problems but the chassis is almost rust free and solid. As I mentioned before, the vari-drive setup are all the same from mower to mower, just the linkage is different from mower to mower. With this in mind, the linkage setup on the green mower is more suited for the bigger transaxle pulley i am using. Plus it has 7 speeds for the vari-drive as compared to the red mower with 5 speeds. The numbers for the ratios are the same, just the shifter handle is longer for the range of movement on the fender which makes it possible for the extra gears, high and low ratios are still the same. This brings the total gears to 35 forward gears and 7 reverse gears. WOW!! I think I should be able to find the perfect gears for cutting my grass, I would think, LOL.

I'll be using the hood, grill, and dash off the red mower for the green mower, just for the look. The original ones for the green mower are long gone, or plastic, or busted up. Maybe some other parts too. Electrical needs cleaned up but is in good condition.

Stay tuned...............