How exactly does the drive work on my grader? My Dad says there are chains inside the housing on the axle.I know when I was plowing last winter I got stuck and the left front dirver and the right rear driver were the wheels spinning. It has a flat tire right now and fixing it isn't high on the priorty list right now but he did want to move ot from where it was.He was afraid that it would snap the chain inside if he moved it too far(tire is junk so no other damage there to worry about).

Yes, they have a separate chain drive to each wheel....sounds like you have a couple broken.

That's what I was kinda wondering after thinking about it.All the wheels should have spun right?It's a 212 by the way.8T model.

Hello,
I have a 212 9T that I was plowing with, all four wheels spin on mine. as far as hurting anything with a flat I had to drive mine close to a quarter of a mile with two flats (bad rims) without hurting anything. one rim actually came apart on the way! getting those rims off the machine whole nother story.

Rob, an 8T is a #12 grader and a 9T is a # 212 grader as dardd2 said.

Thanks for the enlightenment.

Hi, Rob Balfour.
The Cat tandem drive system had no differential. There was a solid cross shaft which ended with drive sprockets inside each chain case. From those sprockets, chains carried the drive forward to the front drive wheel and back to the rear drive wheel on each side. Replacing the chains is not the easiest job you will ever do on a Cat grader but not the hardest either. There is usually some involvement with pieces of wire and/or rope to pull chains out and in - and maybe a little cussing too, depending on your temperament.

It doesn't hurt to have the wheel whose chain you are replacing jacked slightly off the ground so that you can turn it by hand, both to hjelp in winding the chain on and to enable you to get all the slack out of the bottom to assist in connecting the new chain. When you pull the slack out of the bottom, have a timber wedge handy to shove under the tire to stop the wheel turning back and letting the slack go again.

I don't know about the 212's but you could jack up any wheel you chose on a standard, front scarifier-equipped Cat 12 with just the blade and maybe a chock or two.. If you want to jack up a rear wheel, keep the blade square across the machine, lift the front wheels off the ground by maybe 10 - 12" (Usually only the left will come off the ground because of the weight of the lean wheel drive on the right.), then PULL BACK the blade control on the side AWAY from the side that you want to lift. The causes a weight transfer that will lift the rear wheels on the opposite side from the blade control that you pulled back on.

Hope this helps.

Thanks for the info.

Be very careful about driving with broken chains. The chains could get "bunched up" and it the right position, be ruined and or crack the tandem housing. That would NOT be an easy repair.

Hello all!
Looking through posts, this one seems a pretty good one to spin off of, albeit the title says #12 grader vs a 212 9T I’m working on getting home. I kept it on this as Deas’s description of the tandem drive is helpful.

A couple of things-
1. Both rear chains are broken, one is dropped off sprockets but the other is bunched. No sign of broken case. Front chains are intact.

2. When I looked at it, the transmission shifter was stuck tight, but in neutral, I think. I’m not 100% sure on neutral because when I looked at it the owner had drug it from its outside parking spot about 30 feet with tandem wheels not turning and moldboard down.

3. It’s got over 7,000 hours on service meter, but used by same family since early 1970’s.
Current owner has both motors starting. After a little working with it, the shifter has movement to where it will drive forward in two gears, and in reverse. Movement is limited and I asked him not to push it as I think it’s due to the bunched chain. When I pick it up, I’m hoping I can get the bunched chain out of there entirely. Also, the left side gear box has a small rust hole, leaked fluid out.

Couple of questions:
1. Does lack of shifter movement put up any red flags other than for having sat outside for 20 years? Parts book shows shifter forks-maybe it’s like my F/A 560 that hangs up occasionally, (no Torque Amp on this to help out).

2. How does the wheel lock function? There is very little foot clutch pressure and wondering if that’s a cause of the stickiness.

3. I’ve found a couple used 7B1447 chains. Wondering if new are available and if used, what should I be looking for. What new length spec? I think those are 29 links, same chain all around for each drive wheel.

I have picked up a #12 OM and Parts Book; #12 8T1 Parts Book; 212 9T tandem drive parts book; 212 tandem drive 1R1 parts book. Haven’t found 212 grader service manual but have seen 311/212 diesel service manual but not ordered anything yet, too expensive.

I’m hoping to get that bunched chain freed up and use the front tandem rear wheels to get on trailer, or at least get it out so I can push the machine on and off.

I’ve got a couple of projects for this machine this spring and hoping to use for any snow we get this winter.

Thanks in advance, as always and keep safe,
bernie