1981 DMC 1200 Track Rebuild

Perski

New member
I got a 1981 DMC 1200 that I am rebuilding the tracks on right now. First time doing that! I got all the grousers off (that was fun!) and have had them all sandblasted. I am looking for suggestions on a good durable paint to use. I recall reading a thread in the forum regarding a paint that was very durable and great for painting grousers but cannot find it now. Grateful for any suggestions. I was also considering galvanizing which isn't cheap but long lasting. I have another 1200 with galvanized grousers which are holding up very well.

I am also going to need some new tires for the idler wheels. The ones on there seem solid. Not sure if they are foam filled or just solid rubber. Are there options and what seems to be the best way to go on that? I know you can get wheels/tires at Falline but don't have any other sources at the moment. Anyone have suggestions of other vendors?

Appreciate any comments. Thanks!
 

Snowy Rivers

Well-known member
Hi...WELCOME
I am rebuilding the tracks on my 2100....which are similar...Your cat have the J grousers???????
I would love to sandblast my grousers....but too costly for my budget.

My plan is to paint my grousers with Rustoleum rattle can gray.....

As far as tires go.....The Fall line tires are good tires, but again...too spendy for my budget....

You can get some 145/80/12 radial 10 ply tires (Slightly bigger than the 5.30 x 12) and have them urethane filled....At least the fronts should be anyway.....

If you lose a front (Flat)....you will dump the track off.

Are all your wheels the aluminum wheel/hub combo ????

My 2100 came with alloys up front and steel wheels on thew other axles (Air filled tube type tires)

The steel wheels are nearly impossible to locate.

The 12" wheels with a 5 x 5.5" stud pattern were always an odd duck....Nobody makes them now....

I made my own.
3/8" Steel plate (Water jet cut) and machined and drilled to fit the 5 x 5.5" pattern.
Found a readily available 12" wheel. knocked out the 5 x 4.5 centers and welded in the custom ones....
My plan is to run the factory alloys up front and the Customs on the other axles.
May put alloys in the rear too?????

If you decide to go with whatever tire......foam them......You can run the foam filled ones until the tire is nothing but a nasty rag.....And it will bring you home....

Look at the 145/80/12 radials.....
 

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Perski

New member
Thanks Snowy,
My grousers are J-style, yes! Luckily I have a sandblast cabinet where you can put whatever smaller items you want in, close the lid and turn it on and a few minutes later open the lid and you have 3-4 grousers done. I put my little junior helper on that task. 146 done in just a few hours.:)

I looked a little more and found the tread and it was POR-15 that I was looking for. I have not used it but it supposedly dries hard as a rock, doesn't crack, peel or scratch and can be painted over existing rust if you use their pre-treatment products. Since mine are sandblasted I was thinking just paint as is. Galvanization is still on the table though. I need to make a decision. Pic of my older Thiokol 1200 with the galvanized grousers.
View attachment 138854


I have the aluminum idler wheels. Half of the tires are in good shape and then the rest are crappy looking with damage. They seem to be solid rubber. The broken wheel guides on the grousers have damaged the tires. They were already broken when I got the cat. I think I like the solid rubber or at least the foam fill better than air. Nobody wants a flat out in the snow. I do like your custom wheels/rims. Kinda looks cool I think with the white rim and black centers! Maybe chromies on the lugs? Innovative design!
 

Snowy Rivers

Well-known member
The picture shows the alloy wheels on the front axle and the steel wheels.

The tubular galv steel grousers are nice.

There were no "solid" tires used that I am aware of.....Urethane filled tires are heavy.....and are a pain to remove.
Cut them in a vee notch then cut the sidewall all the way around on both sides.....Cut the urethane donut that is left then remove the beads....

Messy too

The steel wheels had a habit of going flat ( Air filled) Then with the tire flat the tire guides beat up the rims.....

I THINK I figured out why the air filled ones go flat......My 2100 came to be with 4 flats....all of which had the valve stems missing.

Careful inspection SEEMS to indicate that the valve stems were sheared off by the tire guides......Getting the track on a berm or other obstruction that causes the track to get on a steep angle in relation to the road wheels will put the tire guide "Ears" right into the valve stems.....

Get the valve stem in the right spot (Rotation) and the guide there too....Zoooooop goes the stem.

Welding a little piece of steel pipe to protect the stem (Like they do on Skid steers used in construction) will pretty much stop the issue.

Thanks for the kind word on my custom wheels.

The wheels were from HOME DEPOT 12" with 4x 4.5" centers ....The rims are the same thickness as the original cat wheels.

$20 each.....So I ordered a few to mess with.
I sketched out the "Snowflake" centers actual size on heavy craft paper and took it to the local steel yard and had them cut them out on their water jet machine.

3/8" plate.....not going to bend or warp..... The old factory wheels were all warped and the centers buckled from over tightening the lug nuts......

The only Caveat is these are 4 inch wide instead of the 3" wide factory wheels.

I have mounted up a fresh tire on one wheel (145/80/12 radial) and the tire guides fit fine.....actually the radial will keep the track from moving side to side better than the skinny wheels do.

I spent hours searching for the 12" with 5 x 5.5 lug pattern....Other than beat up old rusty junk there simple does not appear to be any new stuff made.

I searched the agricultural machine markets as well as other places....ZIP, NOTHING, NADA

OK

If you can't buy it....you make it.....


As far as tires go......I have a family member in the tire bizz (30 year company man) and we discussed the "Snow cat special" tires that sell for $$$$$$$$$$$$$$$$$$$$$$$$$$$$.....

Seems like this is another thing like the track belting rip off.......The belting is pretty much a standard item....Number of fabric plies, thickness of top rubber sheet, thickness of bottom sheet (Or the inner and outer) and the tension rating.

Numbers like 3/330 (3 ply.....330 pounds per inch of width) thickness of the covers 3/16" top and 1/16" bottom or 1/4" top cover and 1/16" bottom cover.

The heavier machines will be better off with a 4/440 1/4" and 1/16" covers 4 ply, 440 pounds per inch of width.

The 10 ply rated inch size tires are scarce these day......8 ply rated tires and fill them
The metric tires are just a tad bigger (Very little larger diameter) and can be had in a 10 ply rated.

Same as car tires....The ply rating does not always mean there are any actual number of plies....just that the tire will handle the load of the rating (Another game that started back years ago in the tire bizz....used to be, if it said 10 ply...it had 10 plies....the rating is a guess as far as the consumer can see)

Looking at the piccy of your cat....looks like the belts are 4 ply stuff....That's a good thing...

Good luck on your kitty.....
 

300 H and H

Bronze Member
GOLD Site Supporter
I looked a little more and found the tread and it was POR-15 that I was looking for. I have not used it but it supposedly dries hard as a rock, doesn't crack, peel or scratch and can be painted over existing rust if you use their pre-treatment products. Since mine are sandblasted I was thinking just paint as is.
Just a reminder from a POR-15 fan. It is not immune to solar radiation, UV light in particular.
It can be painted over with paint that will block UV light. Great stuff I think.
This is not an issue to car guys who use it on the undersides of their cars btw..
 

Snowy Rivers

Well-known member
Personally the galv would be sweet....Sand blast then galv them.

If you are running in snow only the paint will likely do pretty well.

Start running in gravel, dirt and such and the paint is going to get ground off
 

Blackfoot Tucker

Well-known member
GOLD Site Supporter
I think there is some bad advice being passed out. There is a whole lot more to belting than a one size fits all solution....

Brad at Minnesota Outdoors is the smartest guy I know when it comes to snowcat belting, and I would defer to his comments/suggestions. I would urge you to reach out to Brad before buying any belting. He's a great guy, super knowledgeable and helpful and his prices are very reasonably. I say that as someone who has bought from him before, and will again. I did a fair bit of research on this a few years ago... and this is from memory:

1.) Belting has a minimum bend radius. Obviously that bend radius has to be smaller than the radius of your front idler wheel and your drive sprocket.

2.) Belting is designed for certain temperature ranges. Pretty obvious that needs to be appropriate for the temperatures you operate your snowcat in.

3.) Belting can, and does, stretch. The manufacturer will list what the maximum belt stretch is as a percentage. Installing belts that stretch too much will result in loose tracks (that need frequent tension adjustment) as well as cause premature wear on the drive sprockets.

4.) The cover thicknesses are specified as far as top cover or bottom cover and I recall Brad suggesting balanced covers (meaning the same thickness) are what one should strive for. Thicker covers have more compressibility and the grousers are not secured to them as well with the bolts and backing plates.

5.) Belting is described as number of plies (the woven fabric between the layers of rubber) and so many PIW (Pounds per Inch Width). I know Tucker used two ply, 220 PIW belting for years and have switched to three ply, 330 PIW belting. The last time I spoke with the factory about belting they no longer had any 220 PIW belting available.

6.) Belting is usually designed for a specific purpose, usually as conveyor belting for agricultural products, mining products, aggregate products, etc.

7.) Heavier belting, such as with more plies, or thicker covers, or both, will weigh more and it will be stiffer. Both of those characteristics will negatively affect the performance of your snowcat. You're adding weight, increasing the rolling resistance and also the rotating mass. None of those are good things.

8.) Some snowcat owners will buy cheap, used belting and try and save money. Others will buy new belting as cheaply as possible, which likely won't be optimized for snowcat use either.

My opinion only, but I think using anything other than quality belting that meets the snowcat specifications is penny wise, and pound foolish. It's a LOT of work to change out snowcat belts. A 1600 series Tucker (long tracks) has 124 grousers and each grouser has eight bolts. Do the math, that's 992 bolts. On the earlier style grousers two of those are welded studs and six are bolts. (Later style grousers feature more studs.) The nuts sometimes get damaged and will not come off. In the case of a bolt you can pretty easily cut it off, but when the problem is the stud you have to cut a hole in the grouser to access the stud to remove it, and then weld in a new one. Then you have the hole to either leave alone or try and repair. As I said, it's a lot of work, and most of the time you're doing this with the belts and grousers laid out on the ground and you're on your knees. Your knees won't like it and neither will your back.

Think about that when you are considering buying belting....

Several years ago a forum member had his grousers galvanized. I know my snowcat buddy Scott frequently has items galvanized per his customers specifications. As I recall the price is a function of what the item(s) weigh. I also recall it wasn't cheap, at least not by my standards. IF you operated your snowcat only in snow 100% of the time and never hit a rock or gravel or dirt, etc it would last a long time. And the same is true of paint. But the reality is pretty much all snowcats encounter rocks, dirt or gravel in normal operation and that will cause rapid wear of either the galvanizing or paint. For me, either galvanizing or paint would be a waste of time and money.

For tires I'd reach out to Peterson Equipment in Logan, UT and/or Dan Gates at Snowcat Service in SLC. Peterson was a Thiokol/DMC/LMC dealer for decades and they have considerable corporate knowledge.
 

Snowy Rivers

Well-known member
Blackfoot pretty well has it nailed.

The belting that I am taking off the tracks I just got are all over the map.
Some 4 ply with equal cover thickness, some 4 ply with 1/4" top cover and 1/16" bottom cover
Some 3 ply with 1/4" top and 1/16" bottom.

The 4/440 belt with 1/4 and 1/16 covers has a minimum pulley (Tire diameter) of 16"....the stock tires are about 21.6"

From What I can glean from the belting industry reps.....THERE ISN'T A SNOW CAT SPECIAL BELTING......

I have always been skeptical of "Snow cat special anything" other than some hard parts that are fabricated for a particular machine...
Thiokol was a company that pretty much used "OFF THE SHELF PARTS" and avoided special stuff when they could.
The 12" wheels were a contracted item.....

Plies of fabric, pounds per inch of width are the real deal on belting.....

Get into specialty belting....there are oil resistant, high heat and other characteristics that can be had.
Probably don't need belting that can handle 400 F heat.....
 

Perski

New member
I appreciate all your comments and recommendations. Thanks!

Taking the track apart was interesting. Built a special tool out of a box wrench to get the right angle to get into the j-part of the grouser which got about 60% of the bolts off but what I discovered was that the bolts used for the grousers were too small for the holes. Holes are 1/2" and the bolts were 5/16 which allowed the holes in the rubber tracks to hollow out and the washers would sink down into the hole which prevented the box wrench to reach the head properly and it would slip. Of course the heads weren't very deep either which did not help. Tried a lot of different ways of cutting the bolts but ended up using the grinder with a cutting wheel as the fastest way.

I already purchased predrilled and cut to length rubber belts with sealed edges made to fit the 1200 series Thiokol/DMC. I figured it was worth the higher cost to get it cut and drilled perfect. The belts look really nice. I will find out how well they fit I when I assemble I guess. Need to find some good stock material for making new backer plates as a bunch of the old ones are damaged. Thinking about using 1/8" or 3/16" thick 0.75" to 1" wide aluminum profile for that. These tracks have a hinge like link that holds the ends of the rubber track together. In my opinion it seems like this connection would be more prone to rip out than an overlapped connection which some cats have. I think it is very important that the holes through the links, grousers, rubber and backing plate is the same size and that the bolts fit perfect through this sandwich or there will be movement and with movement you get enlarged openings which leads to even looser connections and then possible failures or ripouts, bolt breaks etc. The tracks on this cat was a prime example of what not to do.

I will have to get deeper into the wheels to see whats going on there when I get to my shop next. They are all center nut rims. I also need to get the sprockets redone as they are halfway ripped to threads.
 

Blackfoot Tucker

Well-known member
GOLD Site Supporter
I appreciate all your comments and recommendations. Thanks!

Taking the track apart was interesting. Built a special tool out of a box wrench to get the right angle to get into the j-part of the grouser which got about 60% of the bolts off but what I discovered was that the bolts used for the grousers were too small for the holes. Holes are 1/2" and the bolts were 5/16 which allowed the holes in the rubber tracks to hollow out and the washers would sink down into the hole which prevented the box wrench to reach the head properly and it would slip. Of course the heads weren't very deep either which did not help. Tried a lot of different ways of cutting the bolts but ended up using the grinder with a cutting wheel as the fastest way.

I already purchased predrilled and cut to length rubber belts with sealed edges made to fit the 1200 series Thiokol/DMC. I figured it was worth the higher cost to get it cut and drilled perfect. The belts look really nice. I will find out how well they fit I when I assemble I guess. Need to find some good stock material for making new backer plates as a bunch of the old ones are damaged. Thinking about using 1/8" or 3/16" thick 0.75" to 1" wide aluminum profile for that. These tracks have a hinge like link that holds the ends of the rubber track together. In my opinion it seems like this connection would be more prone to rip out than an overlapped connection which some cats have. I think it is very important that the holes through the links, grousers, rubber and backing plate is the same size and that the bolts fit perfect through this sandwich or there will be movement and with movement you get enlarged openings which leads to even looser connections and then possible failures or ripouts, bolt breaks etc. The tracks on this cat was a prime example of what not to do.

I will have to get deeper into the wheels to see whats going on there when I get to my shop next. They are all center nut rims. I also need to get the sprockets redone as they are halfway ripped to threads.
Perski,

There is a fellow in SLC, Kevin Smith (IIRC) who was a low-volume snowcat manufacturer. He built Lite Foot snowcats and sold the design to Pisten Bully, which they sell as their Scout model. I met him last spring and found him to be friendly, helpful and knowledgeable. He had recently sold his inventory of track parts as well as his grouser manufacturing equipment to Dan Gates at Snowcat Service, which is also in SLC. I suspect, but don't know with certainty, Dan could supply whatever backing plates you need.

The "hinge like link" you spoke of is probably Flexco belt lacing. If you Google it you can find info about the different styles they make and their
specifications.

You are discovering what many of us have already seen first hand: A LOT of snowcat maintenance and repairs have been done by people who were clueless and/or simply didn't care. It's frustrating to clean up the mess they left which usually also involves spending money in addition to the time investment.
 

Snowy Rivers

Well-known member
YESSSSSSSSSS
The mess left behind by others is nauseating at times....WHAT WERE THEY THINKING ????

Blackfoot is spot on......
Snow cats are not rocket science.....Just a piece of machinery that in many cases can be improved upon.....But at the least...the original design did/does work and if taken care of will continue to do so....
 

Snowy Rivers

Well-known member
Here is a picture of the FLEXCO 550 track belt hinge

These were used by Thiokol on several machines over the years.

This was a common hinge for the 2100 and the Spryte.
A much heavier two piece hinge was used later on......The Flexco can be purchased on line readily. "emurdock.com was where I got mine....Reasonably priced and available in many lengths.

The Flexco 550 is easily snapped off at the various points to get just what you need.

The heavier hinges are made to fit the specific belt width.....

I will snap a piccy of the heavy hinges and get it up.

Flexco has a great tutorial video on installing their hinge.

Thiokol used regular bolts, washers and locking nuts and not the fasteners Flexco sells....

Flexco offers cables to go in the hinges...Thiokol used bolts and lock nuts.
The Flexco hinges also had a nylon tube to go over the cable.

All the extra goodies are not really used on the Thiokols.....The factory parts manual shows the Flexco 550 hinge and the nuts and bolts with washers under the head of the bolt and nut....

I am not sure which I am going to use.....Time will tell...
 

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Snowy Rivers

Well-known member
Here are two pics of the other type of track hinge
The difference is obvious.....I can't tell right off where they are from..(Brand)
The one with 8 bumps on it could be a Hans Hall....not sure.

Both of the ones on the track are stout and will serve well.

Many folks like the lap style connection.....I am pretty much a hinge freak......
I like the idea of bringing the track ends together with the track jacks and stuffing a bolt in...then adding a locking nut..
 

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