Lp2 track pins

[Dale Jordan]

What's the type of steel used and DIA of track pins for a Lp2 carrier ? . Dale

[Lynn Eades]

Pin dia. 0.4375" (7/16")

[Mike Kelly]

Originally Posted by Dale Jordan

What's the type of steel used and DIA of track pins for a Lp2 carrier ? . Dale

You may look into using 4140 chrome moly tool steel, it's readily available and it is supplied in either hardened or non hardened state .

Trouble is 7/16" is a old imperial size

the only place I know that may have some in that size is

http://www.ian-stansfield-smith.com.au/

They have a lot of imperial sized steel .

Mike

[Radek]

Know somebody about suplier in UK?

[Ben]

Imperial diameter steel is quite easy to get hold of in the UK, specific types or grades can be trickier but stockists are usually pretty helpful.

A word of caution.

Last summer I saw a carrier that had been completely re pinned. The old track had been heated (quite hot judging by the steel colour) to free it off then all the old pins removed and newly made replacement pins fitted. It looked great and was an impressive job. The problem was, after some miles instead of the track wearing as it's designed to it began to cut and grate itself. The fine swarf was found all over the track, wheels and suspension. It sounded much harsher than the steady hum you get from original track.

I think the material properties of the track were changed whilst it was heated and this caused the track links to become much harder and not behave as they ordinarily would.

I'm sure re pinning can work but care must be taken.

[Mike Kelly]

This sort of thing can get complicated .

One way to check things out would be to get hold of a original track pin in good condition , or better a NOS pin and do a surface hardness test on it . The TAFE I went to had a hardness tester in the workshop . Basically , the tester drops a pointed weight onto the test piece and a scale records the depth of the imprint , something along those lines

The original pins may have been surface hardened mild steel ? Somewhat like many gears are in gearboxes.

http://en.wikipedia.org/wiki/Case_hardening

[ShawnC]

I was told to use 7/16 drill stock. I have two pins done that way on mine right now going to see how they last. I'd rather have the pin wear out then the track itself.

[Lynn Eades]

If any one cares to check it out for us, I have a drawing from Bovington dated 7-2-44.
The material is : M.C.I., B.S.S. 309.
As the track type is listed as "Cast: I would assume M.C.I. refers to maleable cast iron, and that the B.S.S 309 is the pin material?
As this is late war I think they have dropped all the fancy additives (manganese etc) and gone with the M.C.I.
The pin upper limit is ).437" and the lower limit 0.432" This lower limit would allow the use of 11 mm bar stock.
Just for interests sake, the distance between the hole centres (pitch)in a track link is 1.718" plus or minus 0.015"

I would heed Ben's warning, but also wondered what that guy used for pins?

More info: a track weighs 595 lbs, and the ground pressure is 8.8lbs per sq. in.

Dale: note this spec is for a British MkIIIw. Your LP2A will be close. The dimensions listed will be the same. Materials may differ slightly.

[Euan McDonald]

I have used NOS pins and havent had any trouble.
I did have a little trouble removing a pin from a section of broken track as the pin was bent.

[Perry Kitson]

A few years ago, I had some NOS Canadian track pins hardness tested. They came up at Rockwell C 56-57, which I think translates to 633 on the Vickers scale, and 595 on the Brinell scale.
There are merits to using softer pins, that is the pin wearing, not the irreplaceable track shoes. But soft pins will wear quicker, lengthening the pitch of the track and causing trouble at the sprocket. Perhaps with the limited number of miles we put on our machines, the unhardened pins would be something one could live with.

Perry

[Lynn Eades]

Perry doesn't the M.C.I. lend it's self to working with a hard pin? Often the hard material wears more than the soft? One of the advantages of the cast iron is that it is self lubricating because of the carbon (like graphite) content.

[Perry Kitson]

Lynn, you are absolutely right. The cast iron and hard pin are meant to wear together, so that the holes are elongated and the pins are worn to the maximum tolerance that will still properly mesh with the sprocket, getting the most out of both components. The issue most off us have faced is that the pins have rusted sufficiently to remove most of the case hardening, and when we start using the tracks, it is the pin that has contributed most to the pitch lengthening. My reference to using soft pins is only to preserve the track links. Like Shawn mentioned, easier to replace the pins than the shoes.

Perry

[ShawnC]

So would I need to lube the new hardened track pins. If I use oil or use other products dirt will stick I them. If I leave them dry they will where the track shoes out faster then I want. Anyone?

[Radek]

use a graphite

[Lynn Eades]

They are supposed to run dry.
I think graphite would be impractical unless you could drive your carrier through it. :-)
Too hard to get in there. The graphite (carbon) is in the iron already.