replacing ring and pinion on OC-46

[andy b.]

well i finally hauled my "new" OC-46 home late friday night.  it is an older one with the Hercules 4 cyl IXB engine and needs the carb and distributor cleaned up.  i know, it should have a Wico XH1113 magneto on it (and i'll probably convert it back over the winter).
anyway, as the previous owner stated, it doesn't move when put in gear.  i pulled the fill plug on top of the tranny, and i can see the gears shifting into place, and the shafts turning when the engine turns.  the tractor rolls freely (in any gear or in neutral) and the steering brakes work.  i'm guessing it must be something in the ring and pinion, or inside the differential.  the service manual states the final drives must be removed to get the differential out, but it also states the pinion shaft in the final drive must be removed on the OC-46 prior to removing the final drive.  my question is, can i just remove that pinion shaft from the final drive and not pull off the entire final drive?
also, if i need to replace the ring and pinion (the pinion in the tranny, not the final drive), is there a way to get the pinion shaft out without taking the tranny out of the crawler?

thanks for any replies.

andy b.

[scottm]

I just did the same job on my oc-46. The reason that your ring and pinion probably failed is water in the rear-end. It get in there and rusts the torrington bearings and then 1 fails which lets the ring gear move over some and then there goes the whole works. It is not an easy job, the tracks must come off, then the final drive housings, and the weight on the back. The studs that hold the final drives on go thru the frame into the rear-end. The big trouble is finding the parts, you can find them but they are expensive. You can't remove the pinion shaft with out taking the tranny out of the crawler. This is a big job so be prepared for some heavy work. You can check your ring gear by taking the back cover off of the rear-end. you'll be able to see if there are any teeth missing. If you need I can tell you where to get the bearings cheaper than most places. Also put a new shifter boot on to save it in the future.

[PeteAllen]

Might want to check out add on Yesterday's Tractors < http://www.tractorshed.com/cgi-bin/phot ... ifieds.cgi >.  Gentleman has an OC46 for sale and also claims to have many parts he's willing to sell one at a time.  Add number is 78927.  Type add number into search engine on page at above address and it should take you right to it.  Good luck!

[andy b.]

scott, Pete,

thanks for the replies.  i actually called Dozer Joe this afternoon to ask him some questions.  i also called Z-man's to ask questions and check parts prices.  both of them told me the differential probably isn't the problem, they said it is more than likely the final drive pinion (or something in that area).  sure enough i pulled the rear tranny cover off when i got home, and the ring and pinion are perfect.  the diff also seems to be working as it should.  now my problem is the crawler isn't running at present.  is there a way to narrow down which side is causing my problem?  Z-man's said if it was running i could pull back on one steering brake at a time, and if say the crawler started moving when i pulled back on the right brake, then the right side is the problem.

what if i jack one side up in the air and try to turn the drive sprocket with it in gear?  will this tell me anything?  and how do i jack this thing up?  can i just jack under the final drive and under the front track frame crossmember?  i see that the access cover to remove the drive pinion shaft is behind the drive spocket.  can i get the access cover off through the holes in the drive sprocket and move it out of the way enough to see the drive pinion?  i don't have a problem pulling stuff apart (even pulling the final drives off), but i'd rather narrow my work down so i only pull one.

thanks again for any replies,

andy b.

[Blake Malkamaki]

Hold back on one lever at a time and have someone crank the engine. That is, if it will turn over.

[andy b.]

Blake,

the engine turns over fine (thank goodness).  in fact, it should run with a new battery and a carb cleaning.  i was just hoping to figure out what parts i needed to fix the drive problem and order them while i was working on the carb cleaning.  i was going to try using the starter to diagnose my problem, but i didn't want to blow the starter up doing it.  how robust are these old starters?  can i crank it for 3 or 4 seconds in first gear and see what happens, or am i asking for a starter problem?  i guess i can just wait a few weeks until i have time to get the engine fired up.  you know how it is though, a new toy is in the drive-way and i can't resist tinkering with it.

andy b.

[Blake Malkamaki]

I would think the starter would handle that just fine. But, what I meant, was to have someone hand crank it.

[mtncrawler]

Seems to me you'd be best off getting the engine  running if all that's required is a little carburator work. Otherwise I think you're putting the cart before  the horse.