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Snow Trac replacement BRONZE drive sprockets

Melensdad

Jerk in a Hawaiian Shirt & SNOWCAT Moderator
Staff member
GOLD Site Supporter
I posted in another thread that I may have found a source for newly cast bronze drive sprockets for Snow Tracs. The part number is ST52. It shows up in the diagram below as #38 on the drawing.

Depending on the year of your Snow Trac, there were a couple differnet drive sprockets so you should check your sprockets to see if this is the correct one for your unit. I believe this sprocket was used on all the later models Snow Tracs, starting sometime in the mid-to-late 60's and going through the end of their production in 1982.

At this time I do NOT know the cost of the sprockets, or if I will be able to get them cast. However, I thought others might need a set of sprockets and figured it would be good to post this information.

IF YOU NEED NEW SPROCKETS please post to this thread and I will send you the contact information for the guy I am working with in Canada. He used to be the importer for Snow Tracs. He has a Heavy Duty version of the sprockets that he used to have cast and he sold as a replacement part. He is currently working with a foundry to get pricing.

Picture #1 below: My worn out sprocket.
Picture #2 below: The H.D. Bronze Alloy sprocket.
Picture #3 below: Image from the parts manual showing the sprockets (#38, which is actually part #ST52).
 

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GYPSY

Member
Looks worn only on one side. Can it be turned to run on the other side of the sprocket tooth. Also looks like it could be cut out of flat plate by any machine shop with a tracer out of any material you want. That would be a lot cheaper than a casting.
 

Melensdad

Jerk in a Hawaiian Shirt & SNOWCAT Moderator
Staff member
GOLD Site Supporter
They have already been reversed they are worn on one side, and worn BADLY on the other side.

As for going to a machine shop, I thought of that because one of my best friends owns a shop with several CNC machines, etc. However the problem is that these are made of bronze because they are designed to wear. If steel or a similar material is used, the tracks will be destroyed over time. Consequently it is easier and cheaper to replace the sprockets than to replace all the grousers on your tracks!

I would suppose that some sort of a hardened aluminum could be used for the sprockets, but it seems to me that any aluminum would wear much faster than bronze. I don't expect that this will be cheap, but a proper casting should last for a decade of normal use without causing undue wear to the track parts.
 

Mith

The Eccentric Englishman
SUPER Site Supporter
Could you not cast a plate of bronze (which maybe could be done in your back yard), then get it machined to the shape?
 

Melensdad

Jerk in a Hawaiian Shirt & SNOWCAT Moderator
Staff member
GOLD Site Supporter
Mith said:
Could you not cast a plate of bronze (which maybe could be done in your back yard)
My wife doesn't let me play with fire :hide:
 

Rbenjamin30

New member
Hello

I am a new user but have had a 1972 ST 4 for several years which I use to get into my off grid cabin during the winter. I am looking for replacement for the bronze drive sprockets. I have had it for about 6 years and it has been a great vehicle. I am in the Adirondacks and interested in contact with any other Sno Trac owners

I am also looking for a source to re[lace my tracks and an emergency brake

My email is Rbenjamin30@comcast.net if you have any info on sources for replacement parts

You can call at 973 222-1785
 

redsqwrl

Bronze Member
GOLD Site Supporter
hello r ben this is a olf thread, but a good one to revive just the same,.

most folks were getting sprockets from JT foundry in north pole alaska.

Rumor has it they shut down or moved.

There are molds around good luck with your search and post your findings

Mike
 

300 H and H

Bronze Member
GOLD Site Supporter
IF YOU NEED NEW SPROCKETS please post to this thread and I will send you the contact information for the guy I am working with in Canada. He used to be the importer for Snow Tracs. He has a Heavy Duty version of the sprockets that he used to have cast and he sold as a replacement part. He is currently working with a foundry to get pricing....




If it helps the guys with older two band models, I have a brand new set of J&K foundries for two band tracks. I would be willing to lend one of them to your contact, for a pattern, as long as I could get it back when he is done with it....:smile:

Regards, Kirk
 

redsqwrl

Bronze Member
GOLD Site Supporter
Kirk that was wight years ago..... Maybe ?

Throw those sprockets in the truck when you come up, I will call a nonferrous foundry tomorrow and see if they can pull a mold off of a set.....

Please..

I dragged my feet to long and eventually the camo machine will need a set.
Other wise I suppose I will be going poly again.
 

MNoutdoors RIP

Gone But Not Forgotten
GOLD Site Supporter
If it helps the guys with older two band models, I have a brand new set of J&K foundries for two band tracks. I would be willing to lend one of them to your contact, for a pattern, as long as I could get it back when he is done with it....:smile:

Regards, Kirk[/QUOTE]

I have a foundry we work with also we need to keep someone in the casting business making sprockets. Sad news on J&K :boom:
 

300 H and H

Bronze Member
GOLD Site Supporter
I have a foundry we work with also we need to keep someone in the casting business making sprockets. Sad news on J&K :boom:

Do You want to barrow one? I would lend you one for a foundry here in the States..:biggrin: It wouldn't hurt to have two sources for these I wouldn't think, just in case....... There is also a recipie for the propper amount of Aluminum/bronze to get them as per original. The fellow at J&K told me about it on the phone, but I just don't remember the percentages.

P.M. me if needed.

Regards, Kirk
 

MNoutdoors RIP

Gone But Not Forgotten
GOLD Site Supporter
Do You want to barrow one? I would lend you one for a foundry here in the States..:biggrin: It wouldn't hurt to have two sources for these I wouldn't think, just in case....... There is also a recipie for the propper amount of Aluminum/bronze to get them as per original. The fellow at J&K told me about it on the phone, but I just don't remember the percentages.

P.M. me if needed.

Regards, Kirk

Let you know when back in the country
 

loggah

Active member
SUPER Site Supporter
I have a foundry nearby ,that i have used , and they are in the process of pouring some sno-cat steering pulleys for me now. If some one needs sprockets made up it would be no problem. They do aluminum and Bronze,including Bronze for gears. Don
 

redsqwrl

Bronze Member
GOLD Site Supporter
well before we rush off and make patterns and tooling to get going we should make sure that J-T didn't just stop pouring for winter and head south to panama for winter.

I have to believe the molds and patterns are sitting somewhere.

Mike
 

redsqwrl

Bronze Member
GOLD Site Supporter
FWIW the foundry I just visited with said they can pull a part off of a part, Shrinkage is a factor.

This material has a short freeze window. they would create a relief so it would release easily.

and the pricing was weight of the material driven, labor looked insignificant.
 

loggah

Active member
SUPER Site Supporter
Most patterns are a bit oversize,depending on the size of the part,and the material that its made of. On small pieces that are loose work its minimal and most patterns will have a small taper for the work to release from the mold.A pattern for those sprockets could be made out of plywood a bit oversize to allow for shrinkage,that sprocket is simple .I have had a few patterns made for Lombard stuff years ago in the 70's and they were pretty expensive back then, now not so bad lots of patterns are made of styro- foam and plastic instead of wood like in the old days.You could make sprockets with a 3D printer !!:biggrin::biggrin:
 

MNoutdoors RIP

Gone But Not Forgotten
GOLD Site Supporter
well before we rush off and make patterns and tooling to get going we should make sure that J-T didn't just stop pouring for winter and head south to panama for winter.

I have to believe the molds and patterns are sitting somewhere.

Mike

I might know of someone else with some molds also used to be a importer
Of the snowtracs
 

300 H and H

Bronze Member
GOLD Site Supporter
well before we rush off and make patterns and tooling to get going we should make sure that J-T didn't just stop pouring for winter and head south to panama for winter.

I have to believe the molds and patterns are sitting somewhere.

Mike


I was thinking that in another thread a member here was told by some one they know that the building J&K was in is now vacant.... Could be wrong I suppose. I am sure your right about the pattern they were using, it is just sitting some were...

Loggah, Do you think it would be possible to submerge the orginal part in hot wax and then make the oversized mold from that? You could then of course easily remove the wax... I am thinking this may work, but I don't know the orientation, or the amount of shrinkage we are talking here.

Regards, Kirk
 

300 H and H

Bronze Member
GOLD Site Supporter
Hello

I am a new user but have had a 1972 ST 4 for several years which I use to get into my off grid cabin during the winter. I am looking for replacement for the bronze drive sprockets. I have had it for about 6 years and it has been a great vehicle. I am in the Adirondacks and interested in contact with any other Sno Trac owners

I am also looking for a source to re[lace my tracks and an emergency brake

My email is Rbenjamin30@comcast.net if you have any info on sources for replacement parts

You can call at 973 222-1785

Sorry Rbenjamin30, we kinda blew past your post. First welcome to the Forum, and also welcome from a fellow ST4 ower here. Several Snow Trac fans here as you may know.. Glad you found us here.

As for drive sprockets we're working on it as you can see. Stay tuned!:smile:

Regards, Kirk
 

loggah

Active member
SUPER Site Supporter
I don't believe the hot wax would work, im thinking find out the alloy of the sprocket and size and you can figure out the amount of shrinkage. If anyone had a new sprocket ,or one that had only been run in one direction it could be traced out and the extra could be added in and the thickness can also be allowed for. In iron if i remember correctly the shrinkage was about 1/8" in a 12" piece.What is the track pitch on the snowtrac's? Don
 
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3512b

Junior Member
GOLD Site Supporter
that was me on J@j in Fairbanks and yes was told the building is empty
I been asking around on the patterns so far no leads
part on part will give a smaller finish piece, but this is an easy pice to cast just knowing the type of bronze you want to use and any improvements in the design you want to make,
All it takes is money and time........
 

300 H and H

Bronze Member
GOLD Site Supporter
Base diameter is 15 3/8" (acoss the gear at the bottoms of the teeth)

Acoss the tip of the teeth, 17 1/4"

Tip center of tooth to the next tooth center 3 1/2"

Tooth thickness is 3/8"

Margin at top of the tooth is 3/4" and the space between teeth is 2"

14 teeth total, with 7 drive tabs on the inside for bolting to brake drum. (two band track) each of these has a lug on the back, so it isn't really that flat on either side.

Sure wish I had written down the % of aluminum in the alloy, but I was driving at the time I was told.
 

redsqwrl

Bronze Member
GOLD Site Supporter
Exactly, If Molds can be had I prefer to buy them or borrow them.

I have interest from the Wood Technology group where I work, they can and will create a pattern/mold. (this will take time as we are a educational situation)

according to the two non ferous foundry's near me .250 per foot is the shrinkage for Bronze. I still need the material composition. is it truely aluminized?

Maybe this project warrants its own thread. but Rben was looking for sprockets so here isn't the worst place.

Mike
 

MNoutdoors RIP

Gone But Not Forgotten
GOLD Site Supporter
I just had a conversation with Gary Lemke who was the importer into the US
( He started ASV ) of the snowtracs he said he did have the mold at one point he thought but believes it's long gone. I asked how many he brought into the US
This would have been 1968,69,70,71 he thought is was about 30 or so.
Some narrow and some wide tracs
 

loggah

Active member
SUPER Site Supporter
Pure bronze is probably to hard and wears the grouser,i imagine the aluminum bronze comp. is easier on the tracks.
 

300 H and H

Bronze Member
GOLD Site Supporter
I want to say it was 20% aluminum, but I just cann't say for sure...

Is 20% a workable alloy?

Regards, Kirk
 

MNoutdoors RIP

Gone But Not Forgotten
GOLD Site Supporter
I should be receiving a call from someone that worked at the foundry to find out if the mold is available in the next few days
 

Snowtrac Nome

member formerly known as dds
GOLD Site Supporter
bearing bronze is what they were using at north poll I believe there was some nickel in theirs too as they were a darker color and advertised to wear better than the oem stuff was
 
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