Thiokol 4VL registration page

[Thefatsquatch]

The tracks were changed out at some point, I do not know what the "new" tracks are from. All the parts are mild steal and every 5th one was a double stack of square tubing (picture is a single). The original belting was too short and was extended to fit this machine. Most of the wheel guilds are welded permanently like the part on top. When I got done every 4th one is now a double, which go straight across with a small welded pad in the middle.
I have a machine shop in Sheridan, WY that says they will make a mold to make more of the wheel guides as I have been unable to locate any this size available anywhere. I can tell you from experience changing the belting on these tracks is really hard work. There are 64 grousers on each track 10 bolts in each for a total of 640 bolts per tracks.

I will have some tire guides left over once I get my tracks done. I am running the wooden ones, but per the navy test up in Alaska, I am running short tracks every 3rd grouser, and studded caps every other long grouser. But it looks like they just used the old tire guides and welded on some tube. New guides might be a good plan, simply because they wear thin, but I certainly can set my extras aside for you. That certainly is a sweet Trackmaster! Is there plenty of publicly accessible property in WY to cat around in?

 

[Yancey]

There is quite a few places to go in Wyoming, most of the BLM and forest service roads are available. You could even go visit Yellowstone in the winter. They have strict requirements and many snow machines do not meet them, but snowcats do. I am hoping to try in the next few years to go tour it in the winter.

Our cat was purchased from an auction for work, we run a two way radio company and need to get up mountain tops to the radio sites. Many of the hills we go to are closed to the public, but we get to follow the radio site easements with permission.

I would be grateful to have all the old tire guides when you get done with them. Just let me know what you need to get them shipped our way. I am hoping to eventually change all mine to the ones with the bolt on setup. Without the bolts I have to take off minimum of 5 grousers just to get one off. I am hesitant to do much right now as I don't want to mess one up when I do not have a spare.

I have a local fabricator who will make the grousers, but he cannot make the tire guides.

I hope this helps

 

[Yancey]

Update:
1. The chain in the drop down box was good, it was a sheered off axle. I found a fabricator able to make a new axel. Very pricey, I don't recommend breaking one.
2. I found a manual for a "Track Master 4T10" from 1962, http://www.goldcordmine.com/manuals/Thiokol 4T10/4T10_Full_Manual.pdf
This is an invaluable resource for 4VL owners.
3. Found my suspension was set up wrong and have it corrected now, no more binding. This was the cause of the axle sheering off. (Mine does not match the one in the 4T10 manual. My angles are 90-45-45-90.)
4. Had a crack in the engine head and it was repaired at Lloyd's Cylinder head repair.
5. I had a problem with vapor locking, found a solution, I installed Micro Gard fuel filter #33041 at the input to the carburetor. Then took the bypass fuel from the filter and sent it back to the fuel tank. If you do this be sure to put in shut off valves. (There are two fuel ports on the bottom of the tank, one is now an outlet to a fuel filter and then on to the fuel pump. The other fuel port is now a fuel return.)
6. If you have overheat problems, here is a fix. When I got mine this was already done. Install an electric fan between the front grill and the radiator. I have never started to overheat with this turned on.

There was question about the heater location. At some point mine was moved to beside the drivers seat and it will run everyone out of the cabin area if left on too long.

 

[iceberg210]

Got serial 55 4v, does anyone know the approximate weight and shift pattern or have any manuals from them back in the day?
Thanks
ERik

 

[Yancey]

I can not help you with weight, pretty heavy for mine.
The 1958 4VL has reverse far right and up. The transmission is from a Ford F100.

 

[redsqwrl]

Iceberg, if you are the orange 4v posted on fb asking the weight.... ill just point out i think you have a 4vs a (short) mine has a 3 spd reverse is left and up.

They are pretty light by snow cat standards

 

[iceberg210]

Might be a 4vs, the serial plate said 4v serial 55 who knows might be prior to the 4vs officially. I'd imagine it's very light 3k max, yeah it's the old Bonneville County Rescue Cat. I had been looking for one I can haul without taking the tracks off unlike my 3700's

 

[redsqwrl]

You will like it. They are very nimble

 

[iceberg210]

I'd imagine, now just bunches of wood grousers to replace lol. Does anyone have a preference on type of wood?

 

[Cowpunch]

I’m extremely excited to add another 4VL to the list

Utah Scientific/Thiokol 4VL (late 50s?)
Serial: MST20
Ford 223 with a 4 speed

Came out of Gunnison, CO. Looks like originally a Rocky Mountain Bell(AT&T) cat.

Rebuild begins! Any info you may have is appreciated.

 

[vintagebike]

we have littermates. And now have the shop space to get them ready for the 2026-27 Winter

 

[Thefatsquatch]

I’m extremely excited to add another 4VL to the list

Utah Scientific/Thiokol 4VL (late 50s?)
Serial: MST20
Ford 223 with a 4 speed

Came out of Gunnison, CO. Looks like originally a Rocky Mountain Bell(AT&T) cat.

Rebuild begins! Any info you may have is appreciated.

Welcome to the club! What's your plan for the rear clutch/diff/final drive? It appears to be missing... Also, if you need the tire guide/grousers I have a few extras. I had to move them all to clean my shop last weekend, so I counted, and I have really quite a lot.

 

[Yancey]

I’m extremely excited to add another 4VL to the list

Utah Scientific/Thiokol 4VL (late 50s?)
Serial: MST20
Ford 223 with a 4 speed

Came out of Gunnison, CO. Looks like originally a Rocky Mountain Bell(AT&T) cat.

Rebuild begins! Any info you may have is appreciated.

Hi Welcome to the group,

If you need to look at one that is very close to your machine, I am in South Central Wyoming and would be happy to let you get a look at what things should look like. I really hope they had the rear end and had the drop down boxes with the two Axles.
I have a place that made new axles for me and they cost me $1800, but now that he has the print, he can probably make them much cheaper. If you need them, as for the drop down boxes you will probably have to get them manufactured or make them yourself.

It looks like someone tried to fix the exhaust getting inside the cab, this is a problem with mine.

FYI the MST in the Serial number stands for "Mountain States Telephone" it was around before AT&T bought them out.

 

[vintagebike]

until just a few years ago these 4VLs were almost unknown to the SnowCat forums. We found two wrecked Dew Line hulks in Yellow Knife up in Canada and had the Tucker Mafia help getting them to McCall. unfortunately, they were there for a good reason and little was found that was recyclable let alone savable. I did save a few bits that were passed on to others, but the largest part of them , including the total junk axles ,rear ends and the clutch/ brake assemblies, ended up in the transfer station for shredding.

 

[redsqwrl]

until just a few years ago these 4VLs were almost unknown to the SnowCat forums. We found two wrecked Dew Line hulks in Yellow Knife up in Canada and had the Tucker Mafia help getting them to McCall. unfortunately, they were there for a good reason and little was found that was recyclable let alone savable. I did save a few bits that were passed on to others, but the largest part of them , including the total junk axles ,rear ends and the clutch/ brake assemblies, ended up in the transfer station for shredding.

Dont rule out the 4v(s) guys us short guys make up in enthusiasm what we lack in size.....

Parts are parts! Save all the parts!

 

[Yancey]

In a previous post, I gave a source for a manual that is close.
Next time I open up one of my drop down boxes, I will get the part numbers from the sprockets. The manufacture is still in business and will re make any sprocket they ever made. I may get a new set for mine as some of my teeth are rounded off just a bit. I will post the info here. The Chain can be purchased from any really good farm and ranch store. Sheridan, WY. Big R keeps the chains on the shelf in 10 foot lengths.
The single drive shaft rear end is from an International Harvestor TD6 crawler, but I think it had a special outside case made for it. These internal parts are also still available because of tractor restoration enthusiasts. There is a really cool video series on youtube of a guy who rebuilds one.
Unfortunately I have no idea where to get the exposed break parts, the existing bands can be rejuvenated, I am sure they are off some kind of farm equipment. I did discover on my last outing that these can overheat when used hard. (We started smelling burning brake pads, checked and temps the drums were over 300 degrees. Just waited for them to cool off and all was good again. Now I know why they are inside the oil in the OC12.)
I really hope this info helps anyone trying to restore or keep one of these unique machines alive.

 

[Cowpunch]

Thanks for the warm welcome!

No axle/drive system. My plan is to get it running as soon as possible - preferably by March for the Vail Jamboree. So my plan right now is to take any truck axle I can get my hands on (Dana 44 probably) and resize it to the width I need and make a simple brake steer system with the disc brakes. I'd like to keep it as stock as possible so it could always go back to original if and when I find the correct parts. Which unfortunately takes more time.

Hi Welcome to the group,

If you need to look at one that is very close to your machine, I am in South Central Wyoming and would be happy to let you get a look at what things should look like. I really hope they had the rear end and had the drop down boxes with the two Axles.
I have a place that made new axles for me and they cost me $1800, but now that he has the print, he can probably make them much cheaper. If you need them, as for the drop down boxes you will probably have to get them manufactured or make them yourself.

It looks like someone tried to fix the exhaust getting inside the cab, this is a problem with mine.

FYI the MST in the Serial number stands for "Mountain States Telephone" it was around before AT&T bought them out.

They did have the 2 drop axles but one is sheared off so I'll have to repair it. I'll likely have to get new bearings as well. They're pretty crunchy. One issue I'm having is I can't find wheels for the bogies. They appear to be 5 on 4-3/8". I'm hoping 5 on 112mm will do the trick.. I'll keep looking for old trailer wheels because having mismatched wheels will probably drive me nuts.

I'm thinking of fabricating the sprockets and doing a cast urethane to cover them. If the company still exists I'd be interested to see what the price would be.

I would thinking of doing a tractor stack for the exhaust but I was wondering about exhaust fumes in cab... hmmmm

The MST thing is super interesting. Thank you for that. I'm always interested in the details of old things. I also learned something and feel the need to correct myself before someone else does - Rocky mountain bell actually become Qwest/Century link, not AT&T. Not that it really matters.

Yancy, you've been a wealth of info already! I think I did get your track master manual from a previous post. It's been super helpful in the week and half I've had this thing. I saw one on ebay sold a long time ago with original documents... I sure wish we could find that guy and get his manuals.. I'd pay him! (a little )

Also, if you need the tire guide/grousers I have a few extras. I had to move them all to clean my shop last weekend, so I counted, and I have really quite a lot.

I'll be making the tracks and I was going to fabricate my own grousers. How many do you have? Were these originally steel or wood?


I tried rebuilding the starter to no avail. Spins but no torque. I ordered one that should be here tomorrow. I got a new carb as well so hoping to fire it tomorrow or christmas day.

I also began rewiring the instrument panel. Someone was doing some "tinkering" previously. I may post the wiring diagram I made once it's done if it'll help any folks down the road. To that point! Does anyone have pictures or can just tell me what size fuses I need? It looks like there's one master fuse and then 5 more in-panel fuses.


Yancy, I'd love to see your machine regardless but if I get stuck on some details it may become necessary! I go to steamboat and craig a fair amount and have been to saratoga a few times. If I'm going to be in your area I may see if you're not busy. I appreciate the generosity.

 

[Thefatsquatch]

Thanks for the warm welcome!

No axle/drive system. My plan is to get it running as soon as possible - preferably by March for the Vail Jamboree. So my plan right now is to take any truck axle I can get my hands on (Dana 44 probably) and resize it to the width I need and make a simple brake steer system with the disc brakes. I'd like to keep it as stock as possible so it could always go back to original if and when I find the correct parts. Which unfortunately takes more time.

They did have the 2 drop axles but one is sheared off so I'll have to repair it. I'll likely have to get new bearings as well. They're pretty crunchy. One issue I'm having is I can't find wheels for the bogies. They appear to be 5 on 4-3/8". I'm hoping 5 on 112mm will do the trick.. I'll keep looking for old trailer wheels because having mismatched wheels will probably drive me nuts.

I'm thinking of fabricating the sprockets and doing a cast urethane to cover them. If the company still exists I'd be interested to see what the price would be.

I would thinking of doing a tractor stack for the exhaust but I was wondering about exhaust fumes in cab... hmmmm

The MST thing is super interesting. Thank you for that. I'm always interested in the details of old things. I also learned something and feel the need to correct myself before someone else does - Rocky mountain bell actually become Qwest/Century link, not AT&T. Not that it really matters.

Yancy, you've been a wealth of info already! I think I did get your track master manual from a previous post. It's been super helpful in the week and half I've had this thing. I saw one on ebay sold a long time ago with original documents... I sure wish we could find that guy and get his manuals.. I'd pay him! (a little )


I'll be making the tracks and I was going to fabricate my own grousers. How many do you have? Were these originally steel or wood?


I tried rebuilding the starter to no avail. Spins but no torque. I ordered one that should be here tomorrow. I got a new carb as well so hoping to fire it tomorrow or christmas day.

I also began rewiring the instrument panel. Someone was doing some "tinkering" previously. I may post the wiring diagram I made once it's done if it'll help any folks down the road. To that point! Does anyone have pictures or can just tell me what size fuses I need? It looks like there's one master fuse and then 5 more in-panel fuses.


Yancy, I'd love to see your machine regardless but if I get stuck on some details it may become necessary! I go to steamboat and craig a fair amount and have been to saratoga a few times. If I'm going to be in your area I may see if you're not busy. I appreciate the generosity.

Well, mine isn’t done, so I haven’t counted how many tire guides it’s going to take, but I have a Lot. I also have some narrow ones. According to some old navy literature, the wooden grousers with metal caps had less side slipping when every third grouser was the short one. So that’s my plan. I did end up with an extra axle shaft, but they are interesting units. One piece shaft and sprocket, apparently with conveyor belt bonded around the outside.
I am jealous yours came with windows. lol

 

[Yancey]

A few things,
1. Using the rear end from a pickup always gives you forward motion. In the original just before the brake is applied the power to that drive shaft is released by a clutch system in the diff. If you pull both sticks back at the same time you are essentially put into neutral at the rear end with the brakes applied.

2. If your axel shaft sheared off it is because the suspension was set up wrong, there is a set of bump stops on the back wheel that should keep the back bogi wheel and track sprocket from colliding. This was wrong on mine when I got it. There are two springs in the middle and they are slightly compressed all the time if everything is right. If they are fully out something is not right. I had to do a lot of fidgeting to figure out how the suspension works, it is essentially a dual walking beam, but the walking beams are vertical instead of horizontal like normal.
I also had new springs manufactured, not too pricey either.
The bearings are readily available. I got mine at Car Quest.
The sprockets I referenced are inside the dropdown boxes, not the ones for the tracks.

3. There are 64 grousers on each side and they are separated by 5 inches. Mine have 10 bolts each for a grand total of 1280 bolts. Have fun with all of them.

4. The rims and tires should be from a 1948 Ford F100 pickup, same with the transmission. The engine will be the industrial version, but be aware Ford had 8 variations in 1958 of the 223 engine. So sometimes it is hard to get the right part. (My local auto parts stores sometimes dread me coming in looking for parts.)

5. I rewired my dash, I am not sure how it is supposed to setup, but most of my fuses are 20 amp. It will really depend on what you’re running on each wire. I do not have a master fuse on mine. But I do have two master switches. My battery(s) are behind the drivers seat, definitely not original.

6. I would keep your exhaust at the rear, mine is similar to a tractor and I do get some inside.

I am learning as I go, Thefatsquach, Vintagebike and Red Squirrel have all been a great help, I got lucky, mine was complete when I got it.

I tried to message you directly but it won’t let me.

Yancey

 

[redsqwrl]

Cow-punch this what my 4vs has

I only have 10 of those with raised centers but the rest are just flat across the top.

 

[Thefatsquatch]

None of mine have raised centers, but most of them have 4 tabs welded on; two on each side.
Question... Is anyone else going to AVOID flathead screws at all cost on the rebuild?

 

[Yancey]

Mine are all metal, so grade 8 bolts only, so no screws at all.