New to the forum and new gokart project

[toadson]

Hey everyone, I just joined the forum and wanted to share my latest project. I've never owned a go kart, but I have several atv's I am always wrenching on and just wanted to try and build my own kart. I'm lucky enough to have a welder available, and many other tools to help me a long the way.

First off, the frame I am using I got from a friend about 5 years ago. It's nothing special, just some cheap frame I'm sure doesn't cost much new. When I first got it, I extended the frame and added an extra plate in the rear for strength. It's been sitting in a barn ever since, and has rusted up pretty good. I'm also not too fond of some of the welding I did, and plan to clean up the frame, my old welds, and weld in some extra reinforcements. Please ignore the bondo, it's coming off!

Around the same time I obtained the frame, I wanted to build a racing mower. That never happened, and as a result I had this old mower laying around. I will be using many parts off of it, including the rear end and engine.

Here is the engine, a 14.5hp Briggs

The rear end is made by Tecumseh, and has a patent # of 4,966,574. It has neutral, reverse, and four forward gears if I remember right.

It also has a small disc brake built onto it

I'm planning to chop off the front end of the lawn mower and weld it onto the go kart frame. This way I can use the mowers old front axle, which pivots in the middle, and gives me some suspension. I will also have the mounting plate to mount the engine to, which makes things a little easier.

Since I am using the mowers engine and rear end, I am either putting a smaller pulley on the rear end and keeping it belt drive, or switching to sprockets and using chain. I will of course need some sort of clutch on either the engine or rear end.

I'm not sure what I want to use for brakes yet. I will try to use the brake on the rear end, but I'm clueless for the front. Since I will be using the lawnmower front axle, I'm not sure if I could make anything worthwhile or not.

I think this will make a fun kart once I am done with it. I'd like it to sit off the ground a bit so I can take it through some trails, and hope it has decent ground clearance with the mower rear end. Throw some ideas my way if you have any, because I know I am going to need a lot more to get this thing done!

 

[jmorey92]

when people make racing mowers they weld the front axle solid so it doesnt wolble. if you add springs it should fix that though. plus why the clutch if it has neutral???? plus you need to take rearend apart and clean out grease and replace it gear oil perferably. most karts dont even have front brakes so... and you could switch pullys from the rearend to engine and engine to rearend if there the same size shaft

 

[freakboy]

Also add a breather to the trans axle and add better bearings to it. and also you should remove the reverse chain.

you need to lower the front end also and then strenghten the steering dont want that comin appart.

this is only if your building a seriouse racer.

 

[toadson]

Not building the kart to be a racer, that's for sure. I'd use it mainly offroad for running through trails and around the yard. No flat track racing or anything like that.

I don't recall seeing any drain plugs or filler plugs on the rear end. So it is just sealed and full of grease? I guess I may have to drill and tap a drain and filler hole then and run gear oil as suggested. Any reason why I'd have to replace the bearings? I wouldn't mind pulling the rearend apart just to see how it's set up. Also, is the reverse spring you're talking about inside the axle housing?

As for why I need a clutch- if I didn't have one and I went into gear, it would be a little rough on the engine and axle wouldn't it? I'll have to check the shafts tomorrow to see if I can simply swap the pulleys. If so, I may just go with a belt drive system instead of a chain, and probably wouldn't need a clutch then. I'd want a clutch though if I convert it to chain drive.

Keep throwing ideas at me!

 

[jorge0136]

Welcome to the forum.

You appear to have one of the peerless transimissions. I have to call on one of the other elders here to identify which one it is that you have.
Fredric was documenting his experiment with a similar transmission. http://frederic.woodbridgedata.com/index.php?p=boo-ev-truck-powertrain
If you ignore the stuff at the top of the page about the audi differential and scroll down there is a explanation of how it should look and how he cleaned it up a little. As far as the clutch, how did it shift before? I Guess I can't see why you can't take the way they had it shifting on the mower and make it shift the same way on the kart.

In addition if you go to this post http://www.diygokarts.com/vb/showthread.php?t=4766

Kaptain Krunch's comment on there is an article that he has started focusing on lawn mower transmissions.

Speaking of which when you tear the thing down would you mind taking tons of pictures? A picture are worth a thousand word.

I only have rear brakes on my kart, in fact only on one wheel right now and it works just fine. Good luck with your kart.

 

[toadson]

Thanks for the links! If I do take it apart, I will try to snap some pics for you. I believe that the clutch set up on the mower was just a way to relieve tension off of the drive belt, so it would be slipping. It works for mowers just fine, but I don't know how well it would work on a go kart. I may have to end up trying to set up a system like that if I try for the belt drive.

 

[freakboy]

You should open up the case to do a few things. everything is located in that housing. but since you arent racing you dont need to remove the reverse chain. something to keep in mind is do you want to lock the rear end instead of having a differential? if your driving this off road locking it might be a good idea. and you should clean as much of the grease out as you can then drill and tap a fill hole and a drain hole. you can put a fitting on the fill hole and run a clear peice of flexible toubing and that will work good enough for a breather. just have it come up and somewhere were you wont be dumping oil.

 

[toadson]

I cracked open the transmission today and took quite a few pics. To see them all, follow this link: http://s143.photobucket.com/albums/r148/toadson/gokart/transmission/

Outside shot from the top

The axles are 3/4"

This is the top half:

Lower half:

Unfortunately, the axle rides on bushings instead of bearings. Here is a pic of what I am talking about:

I'm wondering if maybe this casing is used in the more expensive lawn mowers, but they use bearings instead of bushings. I had an alternator laying around and stuck it in the groove next to the bushing, and it fits pretty good. The only problem is that the axle is too big for the bearing.

One idea I have is to install grease zerks where that groove is so I can grease the bushings when the transmission is closed up. If I could find the right bearing for a reasonable price, I would install them. I doubt that would be easy to find though, as I don't have a clue where to look.

I did find a perfect spot to add a vent tube, so I may drill and tap that tomorrow. I'm still not sure where to add the drain at yet, as there doesn't seem to be a good spot to drain all the fluid. What I'm figuring is that the gear oil can lube the gears, but I will use grease for the axle bushings.

This tag says "Peerless 915 015 2297 2975"

The differential - seems like a pretty nice one

Not sure what you call these gears, but this mechanism is connected to the shifter and slides through the gears and engages them. Note that there is no reverse chain, but a reverse idler gear.

Rusty shift fork

Lower half cleaned up

Upper half cleaned up

I did find some rust which I cleaned up. I think the transmission is in great shape minus the rust. I just hope the bushings for the axles will hold up.

Anyway, I hope I covered everything I was planning on. I took so many pictures and had a lot of things to remember, so if I forgot something I will have to add it later!

Any thoughts/comments on the transmission?

 

[jorge0136]

I believe the gears you referred to are the spider gears. Excellent photos, shows everything you are looking at there.
It looks like you have the peerless 900 series, I think. Kaptain Krunch doesn't mention those in his article. I wonder if they are any good. I poked around a little bit trying to find a bearing that world work. You could get one custom made.... Yuck.
I think you are right it looks as though one definitely should swap in from somewhere else.

3/4 inch shaft you might be able to install a disk brake on that bad boy for stopping.

Have you decided chain or belt? I don't know how to clutch this thing quite frankly. I am sure there is a perfect way of going about it though.

Does the little tiny disk brake actuate on the tranny?
Looks clean after you washed it.

Great work on all the photos again. Kind of a pain to get all greasy and take photos at the same time.

 

[toadson]

The spider gears are the smaller gears in the differential. The ones I am talking about are the gears you engage when you pick 1st, 2nd, 3rd, etc. I'm just not sure what you call them lol.

I suppose I could install a disc brake on the axles. That would probably be the most reliable brake I could fit on here. The tiny disc brake on the transmission is just a way to stop the transmission from spinning I guess, so it is technically a brake, but I highly doubt it would hold up very long. When I removed it from the casing, one of the pads fell off into two pieces. It could probably be a good parking brake though.

I think I am going to try a belt drive. If I use the clutch system from the mower, I think I could make it work. I just don't know if the belt would hold up very long or not since the engine pulley will be significantly smaller. Plus trying the belt drive is practically free since I have the pulleys and clutch pedal set up. I forgot to check if I can swap the engine and tranny pulleys around though.

 

[toadson]

Installed a vent and a few grease zerks. The vent is just pipethread, so I can remove it and screw in a grease zerk anytime I need to pump grease into it. I decided to go with regular grease for the axles, and John Deere orn head grease for the gears. My dad had some in the shop and told me that it is used in a gearbox on combines that spins at pretty high rpms. As it heats up, in gets about as thin as gear oil. I figured it would be better to use than gear oil, so that's what I went with.

Here's the one part that actually has bearings... the input shaft

Greased up

I put it all back together with anaerobic sealer and plan to pump it full of grease tomorrow.

I think I may have changed my mind on the frame. Instead of using the frame I originally intended to use, I'm going to use the mowers frame. I'm planning on unbolting the upper part so I can sit the seat down lower, and it wont look like a mower either. At least everything will bolt up like it should, except for the steeing and maybe a few other minor things. I may reinforce the frame in a few spots if I have to, but we'll see how it turns out. I hope I can use the clutch system from the mower to make things simpler.

 

[freakboy]

U might wana use heavy weight fluid not grease.

 

[Kaptain Krunch]

Agreed, grease will just get flung off, you need to use some 75w+ gear oil (i like 85w in my transaxles). Just make sure you use some liquid gasket on the cases so you dont get leaks. Also, I'm not sure how well that transaxle will hold up, it really depends on the engine and gearing your using, but the 915 series are not know to be very strong.

 

[toadson]

I guess I can use gear oil since I haven't filled it with grease yet. My idea was to pump it about half full of grease, so I wouldn't think it would cause any problems. Do you think the transaxle is strong enough to hold up for a gokart? I doubt it would ever go over 30 mph at the most where I would be running it.

Kaptain Krunch, do you have any advice on how I should set up a drive belt system? I'm not sure how the racing mower guys set theirs up. I was hoping I could mount the engine in the front and use the lawn mowers old belt drive set up with the clutch and everything, but I've got to thinking that the system may not hold up with different sized pulleys. If it won't I might have to get a bigger frame and mount the engine in the rear and use some sort of centrifugal clutch. I'm kinda stuck at the moment, and need to get a good plan for this thing.

 

[residentg]

corn-head grease?

 

[Kaptain Krunch]

I guess I can use gear oil since I haven't filled it with grease yet. My idea was to pump it about half full of grease, so I wouldn't think it would cause any problems. Do you think the transaxle is strong enough to hold up for a gokart? I doubt it would ever go over 30 mph at the most where I would be running it.

Kaptain Krunch, do you have any advice on how I should set up a drive belt system? I'm not sure how the racing mower guys set theirs up. I was hoping I could mount the engine in the front and use the lawn mowers old belt drive set up with the clutch and everything, but I've got to thinking that the system may not hold up with different sized pulleys. If it won't I might have to get a bigger frame and mount the engine in the rear and use some sort of centrifugal clutch. I'm kinda stuck at the moment, and need to get a good plan for this thing.

I dont think it will hold up too well for a go kart, but if you already got it cant hurt to give it a try. For the belt, just do the same tensioner set up that the lawnmower had, should be fine. Just make sure not to use any pulleys smaller than 4".

 

[Doc Sprocket]

corn-head grease?

Yeah... For greasing your cornheads... Duh!!!



Whatinell's a corn-head?

 

[WI_Chopper]

cornhead is the head on a combine for picking corn

 

[toadson]

cornhead is the head on a combine for picking corn

You got it.

The grease is much thinner than typical wheel bearing grease, and as I mentioned gets thinner once it's warmed up. I think it would work just fine, since it's used in higher speed gearboxes, but may use gear oil anyway.

 

[freakboy]

U guys didnt know what a corn head was??? lol