Greetings All,
Let first say what a great site this is!!!
I've inherited my Grandfathers 1949 HG-68, Serial #44GA642, Engine #2429362, and his oliver #21 two-way plow. He wrote on his instruction manual that he purchased it on 19 Sept, 1950 to replace his team of horses. His 100 acre farm was located in the hill country of Susquahanna County Pennsylvania. The farm terrain was a mix of steep side hills and low flat land that a small creek meandered through. This little crawler was ideal for this diverse terrain and serve the family for many years.
My backround was as a Band Instrument Repair Technician in the Marine Corps and not as a tack vehicle repairman. But none the the less I've charged head and put her up on jack stands. I have disassembled the undercarrige and now need some help going forward:
1. Track Rollers - All my rollers spin freely, but they have side play (thrust) and can be wobbled on the shaft. All the dust covers on the right side have been worn through probably from mowing hay on steep side hills for many years.
-Are new bushings and seals all I should need for these rollers?
2. Front Idler Wheels - The left front idler had 2-3 inches of play so I purchased a new shaft , bushings and seals from Landis Zimmerman when I visited him this fall. The right idler has only minor play so I'm hoping that only bushings seals should correct that problem.
3. Rear Drive Sprockets - Both sprockets seems to have more side to side play than they should have. The outer laminate came unlaminated from the right rear sprocket this fall while plowing snow and will need to replaced. Yes I said fall, the snow started in early November and hasn't stopped since.
- Can the sprockets be tightened up or are the bearing shot?
4. Track Frame Supports and Trunnions - When I disassembled the inner and outer frame supports no spacers were present. The inner support studs on the final drive cases are out of round.
- Can the inner support studs be re-rounded and larger spacers machined to take up the play?
5. Tracks - The pins and bushing seem to be shot. When the tracks are laid out flat on the floor they can be bent into a serpentine.
6. Are there any members on this site from Northern Michigan?
I guess the good new is that the engine was overhauled a few years go so I will only have to sell one of my children to pay for the undercarrige parts.
"1. Track Rollers -
-Are new bushings and seals all I should need for these rollers? "
They sound good, but you don't know til you get them apart. You may find the axles need replacing. The good news is that Zimmerman's prices are considerably less than my last quote from Oliver - about $290 each!!!!! (I built them up with weld and turned them back down to size.)
I don't know that the dust shields do that much, but they shouldn't be expensive.
When you put the seals in, orient them to keep mud out and let oil out to flush the mud away. The seal lip should face the outside of the roller. That's backward from normal practice where the lip faces the oil cavity. All other seals are installed with the lip facing the oil.
And speaking of seals, it's probably a good idea to replace the seals where the axles come out of the transmission. You'll probably have the final drives off if you build up the bosses, so they are easy to get at.
"3. Rear Drive Sprockets -
- Can the sprockets be tightened up or are the bearing shot? "
The sprocket bearings can be tightened - there are shims behind the outer track hangar trunnions. If the final drives have oil in them, the bearings could be ok, but I'd check them anyway when you're into the job this far. And I'd check the bearings on the drive axles as well.
It would help to have a manual to cover bearing preload shimming procedures. I have an OC-3 one, but the HG could be different.
I built my sprocket teeth up with 6013 rod and ground them into rough shape. The track bushings finish the shaping process. Have to watch tooth height - too long and they can hit the frame or the center of the rear track roller.
"4. Track Frame Supports and Trunnions - When I disassembled the inner and outer frame supports no spacers were present. The inner support studs on the final drive cases are out of round.
- Can the inner support studs be re-rounded and larger spacers machined to take up the play? "
Those spacers were a classic engineering mistake! Wouldn't last any time, especially since two of the track hangar brackets had no lube on the front (high pressure) side!!!! I fitted grease fittings to the front of all of them and used grease rather than oil - every couple of hours - to blow dirt out.
Inner supports can be fixed, but it's a labour of love! I pressed out the axle (pushes to the outside of the tractor) and built up the bosses with braze.
Turned an axle to push back in the hole, extended 6" away from the sprocket side. Served as an axle for a fly cutter driven by belt and pulley with a 1/2" electric drill. Fed the cutter in with a bolt tapped into the axle. A real buckshee lathe! Remounted the final drive castings on the tractor to hold them steady.
Used a fly cutter in a drill press to recenter the track hangar hole, with a larger ID. (Could have built them up with braze and brought them back to the ID of the original bushings, but didn't. Why? Just because!)
Then turned the boss down to match the new hangar ID with 1/16 or so clearance to allow for mis-alignment. Removed the axle and replaced the original axles. Bit loose, used locktite and pulled them tight with the two inner cap screws and retaining plate. It's held for 20 years, and really got rid of the slop.
The outer ones are MUCH easier. You can get the trunnion block in a real lathe.
Track pins and bushings - Zimmerman! Last ones I did, the guys with a press and jigs for a 310 case were able to do them.
Good luck; hollar if I raised more questions than answers!
Jack
Thanks for the reply Jack!
1. Track Rollers - I've got the rollers out of the frames but I don't have them completely disassembled yet. When I do, I'm assuming that a worn axle will be pretty obvious, but how about the center raised shoulder of the axle? Is there a measurement of how wide that should be? I wonder with all the hill use this machine saw, that the center shoulders might have gotten worn as well.
3. Rear Drive Sprocket - Yes, I see that my Grandfather's HG Manual Instruction Manual covers reassembling the bearings:
"(NOTE - Drive pinion must be removed to make the following tapered bearing adjustment). Place trunnion and nut on shaft and tighten. Pry ring gear and bearing back on shaft as far as possible and measure clearance between trunnion and tapered bearing with a feeler gauge.
Remove trunnion, and for test only, install sufficient spacer shims on shaft to add up to the measures clearance plus one .012 shim. Again install and tighten trunnion. Test rotation of the ring gear for a definite drag of 2-4 pounds pull at the ring gear teeth. Add or remove shims until this correct adjustment is obtained. Add shims to tighten, and remove shims to loosen bearing adjustment."
How do you think they measured the 2-4 pounds of pull, a torque wrench on the trunnion castle nut? Any thing else they may be leaving out?
4. Track Frame Supports - Your definitely right that the inner support engineering is the weak link. The left inner support stud has worn the support bracket right down to the cover plate mounting hole. When I showed Landis a photo of this area, he advised me to replace the support bracket as well. I like your idea of a grease fitting on the inner support. With no seal to hold in any oil it just quickly runs out.
How's old man winter been up in your neck of the woods? In Northern Michigan we're running out space to pile all the snow.
Thanks Again.
Good morning, Paul.
Snow - we're not quite out of room yet, but the next one!!!!
On your axles, the bushing carriers are more likely to be worn than the axle rib. My notes show 0.6" for rib width. If the rib isn't worn to the oil channel, I wouldn't worry about it. The bushing carriers can be driven in until they take up side play.
There are oil grooves in the bushing carriers where the end (thrust)surface butts against the axle rib. These can be renewed with a file or grinder. Those grooves and the flat on the top of the axle maintain oil circulation for lubrication.
That two to 4 lb pull is a guestimate! I did use a hanging milkhouse scale originally, but then - kinda like a tourque wrench - you get the feel of it.
Have fun!
Jack