Best Manual Clutch Option on a Three Speed Tranny

[adh]

So I bought this golf cart from a friend of mine for practically nothing and so I'm trying to renovate it somewhat. I took the belt system out and put a centrifugal clutch and sprocket so I wouldn't have to deal with the belt slipping so much. The 30 tooth sprocket is hooked up to a 3 speed tractor transmission that is super beefy. If you want more details it comes out of the three speed Speedex tractor. Some how I would like to make this golf kart fully manual but as of know I can't really with just a centrifugal clutch. Any superior knowledge to mine would be appreciated. Thanks

 

[adh]

Another thing I will mention is my gear ratios in the transmission and differential.
1st gear: 3.1
2nd gear: 1.7:1
3rd gear: 1:1

The differential has a gear ratios of about 2.6:1

If I am figuring right that would make my transmission gear ratios times 2.6

 

[G.W]

3D motorsports manual clutch might work

 

[adh]

3D motorsports manual clutch might work

Yes, I have thought about that, but it is kind of a hefty price. I would be spending more on the clutch than what I bought the golf cart for.

 

[G.W]

Yes, I have thought about that, but it is kind of a hefty price. I would be spending more on the clutch than what I bought the golf cart for.

Then perhaps a belt system woth a tensioner pulley. Otherwise I am unaware of other options

 

[adh]

Ok well I think it looks like that the 3d Motorsports clutch is probably my best option and it seems good quality so I will probably go with that.

 

[bob58o]

You are replacing a CVT / Transmission with a clutch / Transmission? Because the belt was slipping? The clutch is just going to burn. CVT was probably correct. The 30T sprocket was probably the problem. Make 30T into 60T and that might solve the problem.

Might not be able to shift on the fly, but that’s what cool about the CVT, it shifts automatically! If you need extra git up. Stop at the bottom of the hill, shift to first gear, then go. At the stop light on a flat street… shift to third gear, then go.

I want to set you up for success so more details are needed. What engine? Tire size, cart weight, number of teeth on all sprockets..

for reference…. My last build was a lightweight minibike with 212cc. In lowest gear, at CVT engagement… my gear reduction from crank to axle was about 16 :1 . And 6 :1 in highest gear.

 

[bob58o]

you have from crank to transmission input, internal transmission, transmission output to diff, and differential internal reduction. You have a lot going on and we don’t know how many teeth on all those connections.

 

[adh]

You are replacing a CVT / Transmission with a clutch / Transmission

I have a cvt on my go kart and it flys around real fast but this was a v belt clutch if that makes sense. It was made for a mini bike back in the 50s or 60s as far as I can tell from my research. You had to use a fractional horsepower v belt with it so you don’t have much surface area to grip. When I changed it to the clutch I first tried putting on my 30 series torque converter but it didn’t fit.

What engine? Tire size, cart weight, number of teeth on all sprockets

On that I have an old 5.5 hp vanguard that I have done a bit of work to so maybe it puts out a bit more. Tire size is 14 inch from tread to tread the cart probably weighs a good 300 pounds. I can barely lift the back off the ground.

I don’t have the teeth in the transmission or differential but I’ll list the final gear ratio at the differential without the clutch and sprocket.

1st: 8.06 to 1
2nd: 7.02
3rd: 2.6

Added to that I have a 12 tooth clutch and a 30 tooth sprocket on the transmission.

 

[adh]

I just had a brainstorm. Is it fine if I would angle the torque converter up instead of angling it down like normal?

 

[bob58o]

I have a cvt on my go kart and it flys around real fast but this was a v belt clutch if that makes sense. It was made for a mini bike back in the 50s or 60s as far as I can tell from my research. You had to use a fractional horsepower v belt with it so you don’t have much surface area to grip. When I changed it to the clutch I first tried putting on my 30 series torque converter but it didn’t fit.



On that I have an old 5.5 hp vanguard that I have done a bit of work to so maybe it puts out a bit more. Tire size is 14 inch from tread to tread the cart probably weighs a good 300 pounds. I can barely lift the back off the ground.

I don’t have the teeth in the transmission or differential but I’ll list the final gear ratio at the differential without the clutch and sprocket.

1st: 8.06 to 1
2nd: 7.02
3rd: 2.6

Added to that I have a 12 tooth clutch and a 30 tooth sprocket on the transmission.

Ok good info! So with the 30 :12 sprocket ratio…

1st 20 : 1
2nd 17.5 : 1
3rd 6.5 : 1
??? Is this what you are getting?

with 5.5 HP engine and 14” tires… I’m ok with 1st and 2nd gear. It’s quite a jump to third, but with 14” tires it’s probably ok.

You could probably run a clutch or CVT provided you made the CVT fit. What size is input shaft on Trans?

 

[bob58o]

I just had a brainstorm. Is it fine if I would angle the torque converter up instead of angling it down like normal?

As long as it had clearance. If looking at the crankshaft side, I’ve mostly seen Torque converter kits with backplates pointed at about 4 o clock, but also 10 o’clock is common. If that makes sense. If talking about 2 o’clock, I haven’t seen it. 4 o clock often requires lifting the engine about 1.5”. Other angles and your likely to have head to jackshaft interference issues.

 

[adh]

As long as it had clearance. If looking at the crankshaft side, I’ve mostly seen Torque converter kits with backplates pointed at about 4 o clock, but also 10 o’clock is common. If that makes sense. If talking about 2 o’clock, I haven’t seen it. 4 o clock often requires lifting the engine about 1.5”. Other angles and your likely to have head to jackshaft interference issues.

Well I don’t have issues with the jack shaft hitting anything so I think I’m going to try it. And yes I understand about the 4 and 2 o’clock deal.

 

[adh]

Just for interests sake, here’s a picture of the type of machine I’m working with.

 

[adh]

Ok good info! So with the 30 :12 sprocket ratio…

1st 20 : 1
2nd 17.5 : 1
3rd 6.5 : 1
??? Is this what you are getting?

with 5.5 HP engine and 14” tires… I’m ok with 1st and 2nd gear. It’s quite a jump to third, but with 14” tires it’s probably ok.

You could probably run a clutch or CVT provided you made the CVT fit. What size is input shaft on Trans?

Sorry about missing that message yes that’s what I’m getting. And the jump to third is pretty big. I’ve got to the point where I can synchronize the engine with the trans to shift from second to third gear but it’s like you are hitting the governor then almost down to idle speed. The input shaft is a 7/8” I got my sprocket from Surplus Center. They have about any size of finished bore sprocket you could ever need. And I have decided that I am going to try to raise the engine an inch so that cvt will fit in a bit better. That will be really awesome with that in. What would you think of me taking down my sprocket size a couple of teeth so I would have about a 12:1 going up to around a 4.5:1? I run that on my go cart with 18 inch tires and it will almost spin on concrete so that should be plenty of torque for this too if I am thinking correctly.

 

[bob58o]

if using the CVT, it changes the ratios. A standard 30 series TAV has an overdrive ratio of 0.9 to 1. So if in high gear … 4.5 becomes 4 : 1.

I would not recommend it.

I’m not sure I understand the set up your planning. I guess I was thinking about putting a 7/8” driven unit on the transmission input shaft.

It seems you are going from crank to driven unit on a jacks shaft, then a sprocket and chain from Jackshaft to transmission input, then is there another chain and sprocket set from transmission output to differential?

 

[adh]

if using the CVT, it changes the ratios. A standard 30 series TAV has an overdrive ratio of 0.9 to 1. So if in high gear … 4.5 becomes 4 : 1.

I would not recommend it.

I’m not sure I understand the set up your planning. I guess I was thinking about putting a 7/8” driven unit on the transmission input shaft.

It seems you are going from crank to driven unit on a jacks shaft, then a sprocket and chain from Jackshaft to transmission input, then is there another chain and sprocket set from transmission output to differential?

Is was thinking of putting the jack shaft setup onto to the engine as it comes. Then I would run my driven cvt 12 tooth sprocket to my sprocket on the transmission. My transmission has a drive shaft from the output to the differential input.
I’ll send a few pictures.

 

[adh]

 

[adh]

if using the CVT, it changes the ratios. A standard 30 series TAV has an overdrive ratio of 0.9 to 1. So if in high gear … 4.5 becomes 4 : 1.

Yes, I know that, but you have to remember at engagement speed it would be around 13:1

 

[bob58o]

Yes, I know that, but you have to remember at engagement speed it would be around 13:1

Yep true, but I worry about the TAV not fully shifting. Clutches of any type relying on centrifugal forces… I’d prefer they are fully locked up. Weights pinned against the outside. I don’t like idea of not getting to that point. I’m probably not explaining it correctly, but if high gear is 0.9 : 1, I want to get fully shifted to THAT ratio. I don’t want a setup where I hardly ever get fully shifted. I don’t want my TAV constantly sliding weights around and stretching and relaxing. Not sure if that makes sense (even to myself, lol). That big jump between 2nd and 3rd is troubling me. 2nd gear seems like a stump puller, 3rd gear might be too fast. Wish you had a 2-1/2 speed. Lol