OC-3 update

[Blake Malkamaki]

Ok, if you can't get the linkage rod ends from a junk yard, you can buy garden tractor tie rod ends that are a little bigger than what you need, but would probably work. That engine has two oil pans - a big aluminum one with a steel sump pan below it. There is no gasket on the aluminum pan, just a machined surface that mates so tight oil should not leak. There is a gasket on the steel pan.

[Jim W]

Blake,

Yes it appears to be the front of the lower pan. Not a big deal to repair. I am in luck I guess. I found a fellow down South who had some OM 621 parts. I was able to get the vacuum line, some of the linkages and the valve cover bracket assembly along with a few other pieces. Hopefull they will be here this week. I can then redo the IP with the vacuum set up. Even the though the used IP I picked up had the same model number I have to hope the internal set up is the same. There are a few parts between the vacuum diaphragm and the plunger that appear to set the stroke/response. as the used pump has three small discs used to space this part I have no way of knowing what the original used. But if this gets me going I will be happy. Sent message to Chris to inquire about a roller and bearings. Also need to look at pictures to see if tracks on the machine are facing the right direction? Not sure if they can be reversed but did read something about that.

Jim

[Blake Malkamaki]

Did Anthony ever say why he took the vacuum diaphragm off the pump? I know he was going to diesel school, so someone - perhaps a teacher - must have given him the idea to rig up what he had. I've just been wondering about that.

[Jim W]

Blake,

He did not think it was needed and as he had swapped out the intake for the short version the linkages etc no longer worked. He did tell me early on that he knows now that was wrong and it needed to be returned to some form of governing. That's where John had come into the picture but I have yet to talk direct with him. The thinking was that some other form of governing could be done. He works for Ohio CAT now so the schooling and work have taught him a lot. Need to get this machine running to put it to work, started grading for the live steam railroad using the Ford and the box grader, not being able to angle makes that job a bit tougher. But with weather in the 60's yesterday could not pass the chance to get some work done.
Thinking about the tracks does it really matter which way they are mounted other than reverse them to even the wear?

Jim

[Blake Malkamaki]

As far as the tracks, the grouser bar goes toward the front. It won't hurt to run it backwards for a while, but the grousers won't clean if they are not toward the front and will load up with mud/dirt.

[Jack in NB]

There's seldom a day goes by without picking up a new bit of info.

Blake - I've always wondered why the tracks were sensitive in orientation.

You just explained it!

Now.... if I can just remember this tidbit next time I need it.....

[Jim W]

Progress   while waiting on the 621 parts I got the alternator wired up and was able to start and operate the machine, Motor is still rough but was able to drive it around on two occasions, Yesterday the linkage and vacuum line arrived so I can get to putting the IP control back to how it was (or close enough I hope). I did try to fine tune the IP timing but was only able to retard timing a little (could not get it to rotate the other way to advance it). Fixed several nuisance water leaks as well.

Jim

[Jim W]

Hard to believe its been almost a month however several things have been done. Pulled the IP and found it was 2 teeth off (retarded wise) and when reinstalled could get her to light right up. Added the vacuum regulator back in the IP as well and built up the control rods and was also able to connect to the original throttle handle for speed control and was able to take several test drives. Spent the last week working on other items but found that when it ran long enough I have a coolant leak around a previously home made gooseneck for the upper radiator to head connection. This part needs to be reworked/rebuilt so now added to the list.
Installed a Delco single wire alternator and have oil, water and soon amp gauges hooked up
Have a roller on the way from Chris however when taking a closer look at the track and track frames I see I have two different types on the machine. It also appears the left side may have a week or broken spring as well. Need to understand how to tell the frames apart. The left side frame has a smaller diameter main spring and spring pad on the frame mount and large diameter (1 .25") spring rods for the front idler wheel. This side also has a rectangular cutout with a bolted on cover just above the middle roller. On the other side the spring rods for the front idler wheel are smaller (1" dia) and are both bent a little downward just before they enter the spring. The main spring on this side is larger in diameter than the other side and has no dust cover. The spring pad on the frame mount is also a larger diameter than the other side. The wear plate on top of the frame mount on this side is a bolted on plate where as on the other side the frame mount casting has the wear plate as part of the casting. The bent spring rods are also causing the idler slide bars to cock over a bit so I do not expect this bend is normal.

So to me it sure seems like the side frame and frame mount have been changed at some point. Do I need to replace the bent spring rods and if so are they all the same on the through holes where they bolt up? Also may need a main spring for the left side but not sure yet how to check this one. For sure that side of the machine has a lot more clearance between the upper track and the wear plate (about 2")even though I have both tracks set to about 2" of sag as per the manual.

The machine has real good slow speed with the dual transmissions!

Blake you were right though she wont light up with out the glows!

Once the motor issues are all settled I will pull it to redo the motor and trans mounts  and then when back in get started on the hydraulics.

Also need to get an input shaft seal for the main transmission as this one is leaking. Will need to replace when I pull the drive shaft to replace the U joint. Anyone have part numbers for the oil seal and u joint?

Jim

[oliverchris]

Eeek! You have the dreaded mix of HG and OC3 track frames. Its surprisingly common. You'll have to decide whether to stay with that. The OC3 undercarriage set-up is stronger, with better idler support rods, better track frame idler guides, better mainspring etc. Let me know if I can help. I have everything in stock, including OC3 track frames, large mainsprings etc. - but at this time no HG mainsprings (the smaller one of your two). I assume your diesel weighs more than an IXB so an upgrade to OC3 undercarriage would seem like the way to go if you don't want a mongrel  

And and to answer your question. The OC3 track fame has the larger mainspring and two square-stock strengthening bars along the front side. The HG has the smaller spring.
Best of Luck.

[oliverchris]

One more important point. Do you have an HG mainframe or an OC3 mainframe? HG will likely have some form of U-bolt over the rear axle spacers attaching to a bracket welded to the rear of the mainframe rails. An Industrial OC3 mainframe has plates extending back beyond that alongside the transmission case. The transmission to axle spacer studs go right through these mainframe plates.

[Jim W]

Chris,

Parts arrived today! Have not checked them out yet though. Ok to be sure the side in my photo is the side I believe you are saying is the OC 3 side frame. This one has the larger main spring however has the smaller idler spring rod shafts that have the bend in them perhaps this was exchanged when the frame was done? I need to check the main frame as well. As there was no builders plate I cant verify the frame however the previous owner Anthony had it listed as a 56 OC 3. He did have the motor etc so I figured he got the info then. The broken roller is also on this side with the larger main spring.

May have to do a road trip your way this summer!

Jim

[oliverchris]

Yes of course, why didn't I look at your profile pic
Yes, the right hand side is an OC3 track frame.

[Jim W]

After more test runs last week end I decided it was time to get the motor off the chassis so the new mounts could be fabricated and the drive shaft rebuilt. A little behind on the rebuild but making progress. Need a few parts and working with Chris on those to solve the main spring issue and a worn track support arm. As the weather has become more moderate progress with pick up.

Jim

[Jim W]

Its been a while but also some work has been done! Motor is mounted with a combo of home made and commercial mounts and a new rear trans mount was built. Radiator is mounted and almost done with the drive shaft. I was able to secure a brand new old stock drive shaft so had new donor parts to fab up a replacement. Using the spline  and u-joint and yokes for the trans side of the new shaft I have them mated to the Mercedes output shaft. Final welding to be done but several test drives have been ok well almost, tonight I put her in 3rd gear to start off after a drive and the temp weld let go. I do have the front original U joint and yokes left over from the new old stock drive shaft and will offer it up for sale. Both yokes are splined and have the set screw taps in place. The u-joint also has the zerk fitting. Have the dozer blade bracket mounted and soon will begin the hydraulics rebuild. A few more parts from Chris soon to be on there way and the track support and spring will be replaced. A few other odds and ends but looking a lot better. Bad thing is the live steam track work needed to get started so a buddy brought an IH dozer over and some of the work the OC was to do is now done. Bad news is that while using the Case 1740 to prep the roadbed I lost a chain tensioner bearing, so its apart now as well waiting on parts. Of course no sense doing one side only and after opening up the other side found that one just about gone as well!