OC3 engine overhaul

[Bill Seal]

Is it possible to sneak the pan off an OC3 42" without pulling the engine, or does the strainer plate get in the way. Looks like only about 1 1/2 inches clearance ovet the track brace.
I found out the hard way that there's no back end on the pan, oil puddles all over the place.

[ozzy]

Bill,  Im not positive about what you mean about 42". Is this the width? Last summer I pulled the pan and head and did a rering job on my OC-3. The hardest thing for us was getting the pan back on. You know trying to keep the gaskets in place. I have aloader on my tractor and the hyd. hoses run under by the oil pan. All in All everything turned out great.  OZZY

[Bruce_Bouton]

Bump this topic as I have the same question. I have a '56 OC3 with 42" track-base (Model OC-3 42). That means I have a tie-bar as shown on page 30 of the service manual; not the simple threaded rod used on OC-3 31", 60" or 68" as shown on page 29.

When I drained the oil it came out in clumps. Previous owner did the classic "throw the stem away" trick on the oil filter so for some unknown number of years this engine hasn't had a working oil filter. I imagine the screen in the pan is a solid mass. The drain plug had brown solid cake on the inside face. Problem is there are two frame member in the way of dropping the pan. One is a beefy 2" tube that came off the frame with four bolts. The other is the tie bar. The picture in the manual doesn't do it justice. There's no way the oil pan comes off while that tie bar is still on.

The directions to remove the bar sound deceptively simple, except this bar holds the track springs in place. I don't find any documentation about alignment.

1. The manual says about reassembly,  "Be sure support spacer is installed under main frame between support brackets." As it is now, the spacer is loose ... has about 1/8" play between the main frame members. I'm thinking this is OK as there's no way I can make the main frame members move inward. OK?  PS: that 2" bar mentioned above was just in front of the tie bar, making that part of the main frame solidly tied side to side.

2. The manual says about disassemble "<jack the front of the tractor up> just enough to relieve the weight of frame and engine from track frame main springs."  I'm guessing the actual amount is "just right" so the tie rod isn't bearing any weight (via the track springs) or suspending the tracks. Sound right?  Are there any gotchas for driving the rod out? Or back in?

Thanks.

[1956oc3]

Hi Bruce, the 2" tie bar sounds like it is not original factory. I just went thru the same thing, the tie bar is very easy to remove. You only have to pull it out 3/4 of the way to clear the pan. Use a bottle jack to support the frame. The hardest part is getting the pan back on while keeping the gaskets in place. best to glue them to the pan, Scottie

[Bruce_Bouton]

Next weekend I'll give it a go.    Thanks.

[commandotom]

When there is a chance that the gasket is going to be displaced as the parts are being positioned I grab some sewing thread and tie the gasket in place.  Don't have to tie every hole just enough to hold the gasket in place.  Use a couple of the holes without the thread to start bolting whatever in place then cut and remove the threads as you run in the remaining fasteners.

[Bruce_Bouton]

OK, this did not go as planned. Nuts are seized. 2 days of getting spritz with ATF / Acetone every hour (daylight hours) while I did other tasks and they wouldn't budge using 4' wrenches. Next I guess I'll have to borrow an air impact wrench.

Two days of waiting for the nuts to loosen let me spend quality time with the rest of the OC-3:

Got the Track Roller oil buttons uncovered. Very likely they've not seen use in a couple of decades.

Other points on the track assembly have zerks where the Service Manual clearly shows buttons. The crud I chiseled away from the zerks tells me they've been using grease, not oil, meaning there's probably no lube getting to all points in the part.

A number of nuts are "backed off" so that I can spin the lock washer with my fingers. The nuts are corroded in that position such that I can't get them to move with hand tools + cheater bars.

The right idler assembly ran in to something stronger than the Oliver. It's been straightened so the idler lines up with the rear, but the track tension fork-assembly is curved. The adjusting nut has been bubble-gum welded in place (looks like about 8" of rod was used).

The fan belt tension adjusting ... call it a sleeve, I guess ... is corroded. Two weekends of regular doses of ATF / Acetone hasn't convinced it to move. I guess the next step is to pull the water pump and carefully use heat on the sleeve.

The electrical system isn't providing any juice. Need to get the engine running (fill full of oil; air cleaner reinstalled) before I can trouble-shoot that. Was hoping to get better tension on the fan + generator belt before doing it.

On the plus side a friend that rebuilds old cars looked at the drawing of how the throwout bearing gets oiled while I asked him for a good local source for oil cup caps said "use a drinking straw until you rebuild the clutch". Brilliant. Better than no oil at all.

I think it's time to retire so I can spend the necessary amount of time stripping this thing to the frame.