Repairing older style dozer final drives D6D

[.RC.]

I am tossing up whether to repair or replace the hub. I got the inner bearing off and while it was tight, the surface area is well worn with evidence of previous oxy gouges from cutting bearings off.

I have not got prices for repairing the surfaces but I know it is not going to be cheap, in fact I expect it to be over half the price of a new one.
There is also fretting where the bull gear bolts to the hub.

 

[.RC.]

OK the cost to repair is substantially more then a new general duty one from Cat. I guess it is what happens when you live in a mining area.

 

[tctractors]

The bearing might have been tight to remove but that would have been only over the unworn area of the hub, the bearing looks to have spun a good bit on the hub, here it would be metal spray treated and cut to standard size for less than half cost of new non OE part. tctractors

 

[.RC.]

Metal spraying is pretty expensive stuff to get done here. Maybe it is the labour side of things. I did not expect $3000 though, but I thought it would not be worth it compared to a new part of CTP brand for $1250.

What is the replacement for the 7M7260 gasket goo. The Cat website which I find is pathetic just says contact dealer.

 

[Nige]

What is the replacement for the 7M7260 gasket goo.

Cat got out of the sealants & adhesives markets years ago. All their products were manufactured by Loctite anyway,
The replacement for 7M-7260 was 9U-5839 (tube)/138-8436 (can w/brush) Liquid Gasket.
The equivalent Loctite product is Hi-Tack Gasket Sealant

 

[.RC.]

What to do here? It is the retainer that holds the thin metal sleeve.
Nothing?
Fill with nickel weld and turn it back?
Fill it with devcon?

 

[.RC.]

I think I have all the parts now. Probably a bit disappointed at the finish on the gears. There does not seem to be any finishing on them after cutting. They look to be cut by the sunderland process. They were not ground finished. But if I do 3 thousand hours in the next ten years I will be surprised.

Can the final drive case be welded. Down where the drain plug is a deep gouge has been worn into the case from tens of thousands of hours of work. I suspect the final drive guard that was on there funnels the rocks and dirt to this area and it needs some buildup done.

 

[56wrench]

As far as i know, they are made from cast steel, so no problem welding. I once welded a patch to a housing where a bent track pad had worn a hole through the case on an old d6c

 

[Dave Neubert]

Yes you can weld them

 

[.RC.]

Thanks, got the case repaired. I also got the bull gear bolted onto the hub. Bolts were a b*****d to do up as they have to go so tight.

 

[.RC.]

Still getting there. A lot of labour in this job. Nothing that is very complicated though.
Got the cab tilted and pinion out. Bearings are all installed except for the outer tapered roller. Steering clutch and brakes are like new.

 

[.RC.]

Slowly slowly does it. Got the sprocket all pressed on today. This loctite tacky gasket goo looks like plum jam.

 

[D5Dan]

.RC. really appreciate the photos/update...having never been that “deep” into a dozer repair it’s VERY helpful to see the before (aka damage), during (heres how I fixed part xyz), and soon the after (I assume it’ll be the video of it pushing!! ; ).
Big fan of this thread...keep up the great work!!

 

[tctractors]

The D6D top pinion is common to see with an extended stump before the thread section needing a longer adapter to be used? tctractors

 

[.RC.]

I had to make an adapter to push the pinion hub back on. The one that came with the puller the thread was too big to fit the pinion.

There is no video of pressing the sprocket back on. It was very unmelodramatic. It just went on.

 

[tctractors]

You look to be pressing up with the 74 Ton cylinder??? also you have a few bits missing off the outer case, lets hope the Duo-cone seal stays put. tctractors

 

[.RC.]

When that picture was taken, only the brand new shiny yellow half guard had not been put on. The guards on the sprocket were all in good order.

 

[.RC.]

Well I tried installing the outer duo cone seals today and seem to have failed. I can get them in no problem. The toric ring sits up against the the outer lip of the seal ramp. I adjust the toric ring so they are well within the 1mm height difference tolerance. I put oil on the faces.

Then I put everything together and the seals butt up together about 5/8" to 3/4" short of where I need to be so the outer plate and nut can not be put on.

How much are these seals supposed to squash up? I know the ramp is pretty deep and if the toric ring was sitting in the bottom of both sides there should be plenty of room but the rings will not go to the bottom, nor will they ride up the metal sealing bit either, they sit in a groove on it.

Or is it a case of brute force needed? I have just been going gently. I used the trick of some electrical wiring held on with zip ties as explained in the installing duo cones seals thread. https://www.heavyequipmentforums.com/threads/installing-floating-seals.36971/

 

[Bluox]

Well I tried installing the outer duo cone seals today and seem to have failed. I can get them in no problem. The toric ring sits up against the the outer lip of the seal ramp. I adjust the toric ring so they are well within the 1mm height difference tolerance. I put oil on the faces.

Then I put everything together and the seals butt up together about 5/8" to 3/4" short of where I need to be so the outer plate and nut can not be put on.

How much are these seals supposed to squash up? I know the ramp is pretty deep and if the toric ring was sitting in the bottom of both sides there should be plenty of room but the rings will not go to the bottom, nor will they ride up the metal sealing bit either, they sit in a groove on it.

Or is it a case of brute force needed? I have just been going gently. I used the trick of some electrical wiring held on with zip ties as explained in the installing duo cones seals thread. https://www.heavyequipmentforums.com/threads/installing-floating-seals.36971/

I measured one of the plastic gauges that used to come with the seals and the installed height .450 to .5 inches above the carrier.
Bob

View attachment 264188

 

[tctractors]

Firstly you do not put any oil on the rubber bits of the seals and the land they sit in has to be dry and also retain the seal complete without the Zip things, the hub adjuster needs to be backed right off so the inner section with the bearing cup slides in. tctractors