transmission question

crawlin · April 25, 2012, 10:28:06 PM

I have an oc4-42-3g 1958 year. It has a four speed transmission with reverse. also has what i believe to be the reverser between the bell housing and the transmission. My problem are with the transmission. The transmission will engage in all four gears and reverse however in first and third, when i release the clutch, the transmission pops out of gear. with all the knowledge that i see on this sight i am sure someone has had this issue before. any information would be greatly appreciated. thanks

paul

hotratz · April 26, 2012, 01:05:02 PM

Well, To address that problem unfortunately you'll have to pull the transmission out. Not a quick fix, you'll have to pull the tracks and finals to get it out of the frame.

oliverchris · April 26, 2012, 02:27:17 PM

As hotratz says, its a time-consuming job, but you can bet your last $$$ it is some kind of wear issue - in the gears and/or linkage. Could be loose bearings and/or stripped leading edge of gear teeth - even worn shifter shafts, I imagine. Either way, it won't go away without getting in there. Best of luck.

crawlin · April 26, 2012, 09:05:25 PM

are most of the parts to rebuild this transmission readily available or is this something that i may be looking forever for? I do not want to tear this thing completely apart, but if i am not spending a small fortune then it may be worth it.

oliverchris · April 26, 2012, 10:57:51 PM

Guestimate time. Let's say worst-case the whole rear-end is junk. You can buy a good runner or a parts machine with a decent differential and/or trans gears. Former $3,000-ish minimum, latter $600 up. Or you can buy a reconditioned transmission from Zimmerman's for ??$1500?? Might be more, if there's clutches or spot-turn unit to rebuild too. I am sure it won't be less than that.
Decent OC4 transmissions are much rarer than OC3 transmissions, in my experience. There's one or two other machines out there that shared the same Clark-built transmission. But let's say you just need new bearings, you might only be into $200 or so. BUT, if there's wear in those gear shaft bearings, there's sure to be other stuff to replace. Makes sense to fix it right, when you have gone to all the trouble of taking the machine apart.

crawlin · April 26, 2012, 11:54:43 PM

I don't mind fixing it right as long as i can get all the parts that i need. It makes more sense to me to rebuild it if i am going to pull it out and get into the gears any how. I am not much of a transmission guy but have a lot of experience in the mechanic field so i shouldn't have to much trouble. That being said, is there a manual that deals with just the repairs and replacements of the transmission and differentials?

oliverchris · April 27, 2012, 12:38:39 AM

There is for OC4s yes. You should be able to get one from Zimmerman's or from Floyd Co. Museum in Charles City, Iowa. (641) 228-1099 Nice folks. http://www.olivertractormanuals.org/olivertractormanuals-2.html

The manual you want is called Shop Manual OC4 and OC46 Tractors (mine is Jan. 1964 - #S1-5-21).

There is also one called OC-4 Technical Service Data, which is harder to get I think, but EXCELLENT! Mine is Jan. 1963 (#S-1-59). It deals with differentials and clutch steering in lots of detail with great photos.

There is also a Parts Manual (recommended) and an Operator's Manual. On these it would be as well to specify which model you have. 4G, 3G or D, or 3G or D Series B.

John Schwiebert · April 27, 2012, 01:03:05 AM

One thing you guys have not covered and I need to look, but if they are like the wheel tractors there is a detent system to hold the gears in place. This could be nothing more than a broken spring. It it rains this weekend I will look. Chris, by the way Clark made those little transmissions for over 20 different O E manufactures.

hotratz · April 27, 2012, 06:30:51 PM

If it's a detent issue you should be able to identify it by the feel of the shifter. It will not want to rock into position firmly and you should feel a little resistance to pull it out of gear.

crawlin · April 27, 2012, 08:47:15 PM

the transmission engages well and feels like a solid shift, the only indication that it does not work is when it pops out of gear as soon as you let out the clutch.

hotratz · April 28, 2012, 02:11:31 AM

ianoz · April 29, 2012, 08:46:23 AM

I don't know about Olivers ,if they are the same as Caterpillar.They have a linkage from the clutch lever that goes to a locking mechinisum in the gearbox that stops the gearbox jumping out of gear .If Oliver is the same maybe the lockout is not being activated . Worth a look .

yorkyjer · May 07, 2012, 12:03:40 PM

There is a seller on Ebay that is parting out old Cletracs.. Don't want to spread his name all over this Forum without his permission, See my post in the parts department .

oliverchris · May 07, 2012, 01:59:35 PM

That's me. Don't hesitate to ask me for what you want. Send a message through this site. I will have a website soon...OliverCrawlers.com (not up yet). But I am now just going away for three weeks in Africa. I have just about everything for HG, OC3, OC4. But, as others will attest, the big stuff can sometimes take me a while to get out, as the crawlers are just a hobby. I mail everything from NY 13637, or freight from Syracuse, NY.
Chris