1938 cat rd7 start drive problems

There is an equipment yard in Garfield WA (eastern WA) called draper tractor.
(http://www.drapertractor.com/) They are the largest one in the area that I know about so they might be who you are looking for.

I am still have some d4 use part and maybe for the RD7 poney too.

I am still have some d4 use part and maybe for the RD7 poney too.

Hey GemDozer,
Do you have the Start drive for the RD-7? I don't know what parts I need for the D4 yet, but I am interested to see what RD7 parts you might have.

The serial # 9g-2410w

Then it would be a 1936 model RD7 with this version of starter pinion.....not nearly as common.

i went to Jensale to try to find a manual. The only one they had was a Op manual. Is there any place else I could get directions to adjust the starter pinion?

That early style pinion doesn't have an adjustment.....not until serial numbers got higher like the first post picture where you have the screw adjustment for the spring on the latches.

Try here for manuals......info on these early models is kind of sparse.
http://www.cat.com/cda/layout?m=90800&x=7

Can the start drive be rebuilt? Can it be coverted to air or electric? I am seeing alot of D7 and RD6 parts. Can they be adapted? I am about to take the drive apart and would like to know every option that can be taken. The pins on this cat have been rolled and the guy that help aquire this thorn(he was the go between man) said that it had 50% tracks. I worked for Cooper Energy years ago on alot of big Iron (nat. gas compressors) but know nothing about tracks. I have had this cat for 5 years. A lawyer friend of mine in billings wanted a sizable cat for his ranch and this gentleman in Idaho had been finding equipment for me found this old cat at CanAm. He said that it was not good enough to log with but everything worked on it and it would be ok for flat ground. So I fronted the money (4500), but when it got to Billings they had to push start it and when they backed it into place a track came off. the lawyer said it was blowing white smoke also and leaking antifreeze. In the end it turns out the guy had bought it as a parts cat(2500) and pawned it of to us as good(I think the guy was in cahoots with CanAm). I got stuck with it of course. Enough of the negative, the good is the engine runs great, the white smoke was fuel so old it was dark purple. The pony motor after I had thoughly clean the fuel system runs like a champ. The track was only half way off and popped right back on. the plate that the big spring buts up to had bolt missing and had cracked. The radiator had a triangle peice broke out where roll cage come down and bolts on, an easy braze for a good welder(which I am not). The only thing I can't figure out is this start drive. It's like nothing I have ever seen. I have never used a semi-U blade but it looks like it could push alot of dirt.