8 speed WH tranny in 6x6 amphibious ATV

[4wheelsis2toofew 23]

I like amphibious ATVs, and living in northern Minnesota, they're what you need to handle the terrain, which is thousands of small lakes, separated by soft ground, all of which is frozen and snow covered for a lot of the year.

 

I have an early 70's Attex 6x6 amphibious ATV that had a predator 11 horse 4 stroke swapped into it.

 

The original transmission was a Baker-Hill monstrosity, most of which is missing, and the parts I have are broken. The Baker-Hill has a CV clutch driven gearbox for forward/reverse (see picture), the shaft you can see is one piece all the way through the gear box, skid steering was by 2 outboard planetary gear sets controlled by 4 disc brakes. (missing)

 

My intent is to replace it with an 8 speed Wheel Horse transmission I got when scrapping out a neglected Wheel Horse tractor. It will sit amidships, roughly as seen in this picture.  I have to move the battery, and I might have to flip the engine around too, or perhaps I'll put the tranny in the back, and move the motor to the middle, I might need a jack shaft instead, so I don't end up with 4 reverses and two forward gears. (I had a friend accidentally do that with a 2 wheel drive motorcycle/sidecar)

 

I plan to mount a disc rotor on each side as a steering brake, and then a sprocket to drive each side.

 

I'm still not entirely sure what tranny I have. The axles measure 1-1/4ish, and if I spin one wheel, the other goes the other way, so I assume it's open vs limited slip.

 

The donor Wheel Horse had model/serial numbers 91-12K802-12619 and 9050.

Edited May 9, 2021 by 4wheelsis2toofew

[Maxwell-8 4,359]

Should be out of a c-121 6 speed 

Open diff (8pinion) with the 1-1/8inch axles. 

54 minutes ago, 4wheelsis2toofew said:

The Baker-Hill has a CV clutch driven gearbox for forward/reverse

A friend, is gone try to use MTD vario drive as a clutch and variable speed on his WH

Edited May 9, 2021 by Maxwell-8

[Wheel Horse 3D 3,795]

Oh yeah! Gonna be watchin this build!

[gwest_ca-(File Mod) 11,137]

This should be the transmission model.

Click on the fuzzy picture in the link for more.

Garry

[Digger 66 3,488]

Looks like a fun build . do they still manufacture axle seals for it ? 

[kpinnc 12,807]

Awesome concept! I have often times thought about using brakes for turning sharper. The D-series hubs were drilled for a brake disc, and will fit those axles. 

 

Looking forward to the build!

[4wheelsis2toofew 23]

Here is a picture of the double disc steering caliper on one side.

It's a goofy system. I might reuse it, if it lines up, but I'd think a pair of motorcycle hydraulic calipers would be better, but I might use some other mechanical calipers I have off of another 6x6.

 

For those unfamiliar with these vehicles, here is a picture of the wheels from the project vehicle, currently mounted on my Argo 6x6

 

[ebinmaine 68,887]

This looks cool. I'm in. 

[Pullstart 63,205]

and cool project!  Does/will it float?

[4wheelsis2toofew 23]

3 hours ago, pullstart said:

Does/will it float?

Oh, most definitely. It's fully amphibious, and can drive right into and out of water without any special preparation. It'llswim carrying up to 700 pounds. 

Here in Minnesota they are used a lot for waterfowl-hunting/fishing and ice fishing in winter.

 

Propulsion in water is by the wheels spinning, which is good for 3-4 mph. It can also be fitted with little paddles on the wheel rims, or it can swim a little faster with tracks (they go around the wheels).

 

 

[Tractorhead 9,065]

These 6 Wheelers are pretty Cool machines.

I seen one about 10 years ago at an Offroad Day‘s here.

 

 

[littleredrider 409]

I almost got one couple years ago. Right place wrong time, as usual. I looked em up, did alot of research, but can't remember any of it now lol. Interco makes a tire that are perfect for these, they are like a paddle, and can go pretty good in water. I'll see if I can find a link or a pic. But I think there is a website that specializes in these, again I'll try to find a link...

 

[slim67 2,737]

13 hours ago, 4wheelsis2toofew said:

Here is a picture of the double disc steering caliper on one side.

It's a goofy system. I might reuse it, if it lines up, but I'd think a pair of motorcycle hydraulic calipers would be better, but I might use some other mechanical calipers I have off of another 6x6.

 

For those unfamiliar with these vehicles, here is a picture of the wheels from the project vehicle, currently mounted on my Argo 6x6

 

Didn't they usually come with the Rolligon tires? I know there were/are several manufacturers of those. Amphicat is probably the one Im thinking of. Id like to have one myself someday along with all the other stuff on my list.

[4wheelsis2toofew 23]

10 hours ago, slim67 said:

Didn't they usually come with the Rolligon tires?

They originally did have the "hubless" style of tires, I think those tires are hard to find now.

I'm going to use modern ATV rims/tires for my project, as they're more available, and this current rig is going to be more for snowplowing and light hauling than my Argo 6x6, which I'm keeping light for better swimming capabilities.

This project 6x6 is fitted with a full length metal skid plate, so it's already a little heavier than stock.

[slim67 2,737]

53 minutes ago, 4wheelsis2toofew said:

They originally did have the "hubless" style of tires, I think those tires are hard to find now.

I'm going to use modern ATV rims/tires for my project, as they're more available, and this current rig is going to be more for snowplowing and light hauling than my Argo 6x6, which I'm keeping light for better swimming capabilities.

This project 6x6 is fitted with a full length metal skid plate, so it's already a little heavier than stock.

I cant wait to see it done. Have you ever gotten one stuck?

[4wheelsis2toofew 23]

15 hours ago, slim67 said:

I cant wait to see it done. Have you ever gotten one stuck?

 Not personally

[tom2p 2,394]

a school friend had one back in the 70's 

 

recall that thing was a blast - went everywhere and almost unstoppable 

 

also recall his had some sort of chain or belt issue (?) - possible something was out of alignment and the chain or belt or whatever kept coming off

 

[Wheel Horse 3D 3,795]

There was a popular mechanics issue WAAAY back that had a full build for something similar..ill have to see if I can find it.

[Wheel Horse 3D 3,795]

Sorry, was Mechanix Illustrated lol. The MI Marauder!

This is a small version, but the core is the trans axle transmission(TAT)

https://www.vintageprojects.com/sites/default/files/articles/six-wheeler.pdf

[4wheelsis2toofew 23]

12 hours ago, tom2p said:

also recall his had some sort of chain or belt issue (?)

 

Amphibious 6x6s tend to have a silly amount of chains and/or belts.

 

I have three different ATVs, all with different configurations. The simplest has a transaxle and 6 chains. The most complicated (current project) has I think 8 or 10 chains in total.

 

Mine are from the 1970s, and borrow a lot of design from snowmobiles.

 

 Most use a CV clutch between engine and transaxle, some people fit a centrifugal clutch instead.

 

On the current project I think I'm going to use the old gearbox (gutted out) as a jackshaft between the motor and the Wheel Horse transmission.