HG & OC3 Question

[dgottman]

I'm real new at this.  Can someone tell me the main differences between the HG & OC3?  Also, which is easier to find & restore?

[John Schwiebert]

There is very little difference between a late HG and the OC-3. To me there are more differences between an early HG and the late HG models than between a late HG and any OC-3

[dgottman]

[size=34]When were each of them made?  Which is older & which ones did they make the most of?[/size]

[thecatskinner]

The HG became an OC in 1951.  By the time it became an OC the only real change was the decals.
The most noticeable change along the way is probably front idler wheels.  The original HG idlers were cast and ran inside the chain.  Th OC idlers were pressed steel and ran on the outside of the track chain.  While this is normally referred to as the OC idler the change appeared I think two years or more before the OC designation.
Other changes along the way to the HG were increased engine size and the frame configuration.
Also the drive sprockets changed from cast iron to steel with segments.
I don't have any numbers for total production.

[pvcarey]

also one thing more that I have found is that the pinnon gear bearings on the final drive were moved from the gear to the shaft and from ball to timkin
Ron

[dgottman]

Thanks for the help.  I certainly appreciate it.

[thecatskinner]

I forgot to welcome you to the site.  It is good to have you aboard.

BTW the HG in the picture is a 1951 and is an OC in all things but the decals and the serial number.  I was one of the last of the HG models.