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Repairing older style dozer final drives D6D

.RC.

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Joined
Nov 27, 2012
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Location
Qld, Australia
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.

20220627_112415.jpg 20220627_112452.jpg 20220627_112505.jpg
 

.RC.

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Nov 27, 2012
Messages
730
Location
Qld, Australia
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.
 
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tctractors

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Oct 9, 2007
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Worc U.K.
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.

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Nov 27, 2012
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Qld, Australia
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.
 

.RC.

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Joined
Nov 27, 2012
Messages
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Location
Qld, Australia
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?

20220701_121547.jpg
 

.RC.

Senior Member
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Nov 27, 2012
Messages
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Location
Qld, Australia
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.20220706_171548.jpg
 

56wrench

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Dec 4, 2016
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alberta
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
 
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D5Dan

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Sep 29, 2021
Messages
119
Location
Oxford, Maine
.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

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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.

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Messages
730
Location
Qld, Australia
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.

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Joined
Nov 27, 2012
Messages
730
Location
Qld, Australia
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/



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Bluox

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Jun 19, 2010
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WA state
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

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Oct 9, 2007
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Location
Worc U.K.
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
 
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