D6C final drive problem

[JEVANS]

Hey Guys,

I got a guy who asked me to have a look at his D6C that he was concerned about, because the final drive oil level kept dropping, but he didn’t see any signs of external leakage. When I got there I noticed immediately the sprocket looks crooked. And there is a massive gap between the sprocket and the housing/Body it runs on. Then He showed me a chunk he found when took the guards off, which turned out to be a hunk of the Toric ring as far as I can tell. A big fat hunk of O-ring about 4” long. Theres also oil all over the inside edge of the track and all around the area. I just was wondering what kind of adventure Im signing on for with this job? I suspect there is likely mass carnage going on behind the scenes, just hoping its not too far gone already. I figure its better to fix it because he knows the machine. He has ran it enough to know the engine and torque are good. Trans is working good and he likes it overall. If a guy auctions it off and buys another machine, who knows what new problems you might inherit.

Anyway, hoping to get a little insight so Im not going in totally blind. Hes gonna pull machine up close to his shop, giver a good washing and then we’ll get at er.
Hoping I can borrow the press to pull the
Sprocket, might not need it though if its worked loose? Anyhow, thanks in advance for any help, advise, or pointers.

 

[OzDozer]

You've got major final drive surgery in front of you. The bearings on the sprocket shaft have more than likely collapsed, or the sprocket has come loose on the sprocket shaft.
You need to break the track, unbolt the outer hub support, unbolt the inner diagonal brace caps, and jack the tractor up and secure it on solid supports, so the sprocket can be pressed off.

You'll definitely need a press to put the sprocket back on, it needs at least 50 tons to ensure it's properly tight on the splines.
The track frame needs to be out of the way to allow the sprocket to come off.

If the sprocket is still tight on the sprocket shaft, ensure you leave the nut on the shaft to prevent the sprocket from flying across the shop when it lets go.
Stand to one side when pressing with serious pressure, it can sometimes take up to 70-80 tons plus a whack with a 14lb sledgehammer, to get the sprocket to pop off.

 

[JEVANS]

I kinda figured as much. I guess I won’t truly know until the evidence is revealed as to what all happened. Hopefully it doesn’t turn into too much of a gong show, but that can be fun too ! Lol. I remember doing a final on a 8K years ago with a guy from Union tractor, we had around 90 or 100 Tons and the sprocket still wouldn’t budge. Had to wail on it with a sledge to get it to pop. Damn near ruined a good set of pants that day! , what a BANG!
The Guy has a skid steer and decent size Hoe at his place, so should have enough support equipment to manoeuvre the big chunks around, I doubt my crane is big enough to lift the track frames. Lol. Do you know if those tracks have alligators on them or will I have to pound out a pin? I kinda looked but It was dark and I figured it might be underneath where I couldn’t see it.

Is there a pile of other special tooling a guy will need for this ?

 

[OzDozer]

If it's got alligator master links, you will spot them quickly and easily from the zig-zag join line - otherwise, you're going to have to find the master pin with the recessed hole, and do some pin pounding!

No need to lift the track frame, just roll the track forward out of the way of the sprocket, and then just jack the tractor until the sprocket shaft is well clear of the track frame.

You will need screw-on pulling/pushing adaptors to fit the end of the dead axle, 3 puller legs with adaptors to pull the sprocket, and a big tube collar that fits over the sprocket shaft that fits between press and sprocket, to enable you to push the sprocket on.
Of course, you'll need the Cat press cylinder with the ears to enable attachment of the sprocket puller legs.

Holding the sprocket up with the crane will assist in reducing sprocket shaft and thread damage.

Check for condition of the woodruff key and its machined recess in the end of the dead axle that locates the outer hub, and check the dead axle for bend. Surprisingly, they often bend in a forward direction.

 

[JEVANS]

Awesome. Thanks for the information. Im sitting here thinking about the dead axle bending forward and it kinda makes sense that it would bend forward the way Im thinking of it.

 

[.RC.]

I found it a reasonably easy but time consuming exercise when I did one side of my D6D. And I have now done a grand total of one. I even did the top pinion seal and bearing which can only be removed via the steering clutch compartment.

You can read about it starting here -->> https://www.heavyequipmentforums.co...er-final-drives-d6d.92115/page-2#post-1054686

 

[Dave Neubert]

you can jack the back end up high with the track frame unbolted from the rear and get enough clearance to remove sprocket with out removing track frame completely. I just did a D7 a few weeks ago look back at my post to see some of the tooling you will need

 

[tctractors]

The D6 C/D/E final drives are not to bad to tackle, I never leave the frame in place and do the jack up thing because I find it just makes it a pain and takes longer to do, this is no slight to Dave as we all do things our own way, if the blade is off it helps things as then you split the track at the sprocket end and leave the frame sat on the track and pull it free off the equalizer bar out and away, or remove the top roller mount and just push the frame forward (bit more work) I would easily have the track split, frame pulled, sprocket pulled off, and outer case away in less than 8 hours, in a good yard with a concrete patch and no puddles probably 6 hours by myself, there is always a few case bolts that have wear that can take a few moments to remove but there is fancy sockets for these that you beat on and they work well, I have done probably a 100 D6 final drives in my life and find them fairly straight forward to tackle, I don't get many F/Drives to do now in a year due to the High Drive thing, I do plenty of them and they are easy, although I did do a D8H F/Drive a few weeks ago, best of luck with your repair.

 

[JEVANS]

Thanks everyone for your helpful advice! I will be getting after this fairly soon, but mostly in my “spare time” ( , spare time) guys not in a huge rush and my Day job keeps me fairly busy.
What would you guys figure would be a worst case scenario for price? If it ends up being all bad, everything is toast kinda thing. Just curious if it would be stupidly expensive or somewhat reasonable? Im up in AB Canada so I have finning available if need be, but likely would try to source somewhat cheaper parts if possible, like through union tractor type of thing.

 

[OzDozer]

The Italian aftermarket parts such as ITR and CGR Ghinassi are probably the best value and the most readily available parts. Genuine Cat parts pricing will set you back on your heels.

RC said his final drive overhaul ended up costing him US$5500 in parts alone, and I think that's probably a reasonably good average repair parts cost.

RC didn't include any of his labour cost for the repair, as he did it all himself - and as a poor ol' cattle baron, we know he always works for no financial reward!