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Cat d6c final drive leak

keith-50

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Joined
Oct 12, 2012
Messages
90
Location
Elgin,TX
I have a d6c, 10k-3438 leaking on back side of sprocket,ck oil level and found very low..I added four gal,s of oil and noticed oil pouring out of seal on back of sprocket, Blocked up tractor, removed outer cover and found, dead axle nut loose, proceed to dissemble right side,final, found holder support pulled off by hand.Pressed off sprocket,, removed cover, and found bearings pitted but still intact,, My concern is dead axle key way is at 7:00 instead of at 12:00. I don't know if axle has turned, or if last repair someone ser axle at 7:00, Also big nut under tractor had no wire ring, but it did have lL shape pin on top side of dead axle holding nut in place. IT does not appear that axle has turned or pin would have fell out.please help thank you
 

.RC.

Senior Member
Joined
Nov 27, 2012
Messages
1,154
Location
Central Qld, Australia
I have seen an experienced mechanic pull a turned dead axle and just replace it, I have also seen the same mechanic pull a turned dead axle and he got in a line borer and bored and bushed the dead axle housing as the taper was damaged.

Either way you will be pulling it. As you probably know, there is a dimension there to measure as to how far in the axle goes.

And that is about the limit of my knowledge on them.
 

keith-50

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Joined
Oct 12, 2012
Messages
90
Location
Elgin,TX
I took a measureme1000004947.jpgnt before I pressed axle out, My service manual says from case, steering clutch to support on end of alxe inner edge, should be 13" I have 12",which makes it shorter, which should tighten final drive, not loosen and cause a oil leak at seals.I attached 1000004954.jpg1000004945.jpg
 

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keith-50

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Oct 12, 2012
Messages
90
Location
Elgin,TX
COULD THE OUT SIDE end of axle with taper end and key way be worn, allowing support to go on too far, and maybe I LOOSE AN INCH there, I verified with cat tech, I am taking measurement at correct locations.
 

LCA078

Senior Member
Joined
Sep 29, 2019
Messages
450
Location
Austin, TX
Does anyone know the size of the taper on these shafts? And what the thicknesses are supposed to be at the start and end of the tapered area? Knowing this should inform you if your deadshaft if the correct one at least. Losing and inch is a lot of wear but I don't see it being worn that much from the pics.
 

pittsburgh cat man

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Joined
Oct 20, 2024
Messages
123
Location
saltsburg pa
We always measured from flat at outboard side of shaft behind outboard threads to machined surface of the clutch housing. The questions that pop into my head are was the outboard hub tight when you took it apart did you have to use a press to pull the dead shaft and my other thought would be was inner nut tight? To be short a inch I would think you would be close or out of treads on inner nut
 

keith-50

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Joined
Oct 12, 2012
Messages
90
Location
Elgin,TX
both out side and inner side nuts were loose, also outer holder assembly pulled off by hand on dissembly, I did not have to press if off. I did have to use press to remove sprocket and I had to use press to remove axle assembly
 

pittsburgh cat man

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Joined
Oct 20, 2024
Messages
123
Location
saltsburg pa
A couple more thoughts If I remember right most of axle/dead shaft instalation instructions tell you to press dead shaft in hold pressure on shaft tighten inner nut then drill new hole for lock If you only have one hole I would wonder if it was put in right last time also I would be looking for a part number on dead shaft/axel to make sure it right one for your machine who knows what was done to it in 60 or so years
 

.RC.

Senior Member
Joined
Nov 27, 2012
Messages
1,154
Location
Central Qld, Australia
In the circled yellow in the attached photo below, is that a wallowed out area from wear?

You can see the original machining marks on the taper on one side, but they are worn away on the other.

As for the inch. I think it may be you were given the wrong measurement or measured from the wrong place. An inch less then it should be would mean massive track frame misalignment, and I doubt you could get an inch out without the diagonal brace bearing hitting on one side of the machine frame.

I do not know what the D6C manual says, but the D6D manual says to install the outer support hub and you use that to measure from.

1000004947.jpg

 
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.RC.

Senior Member
Joined
Nov 27, 2012
Messages
1,154
Location
Central Qld, Australia
A couple more thoughts If I remember right most of axle/dead shaft instalation instructions tell you to press dead shaft in hold pressure on shaft tighten inner nut then drill new hole for lock If you only have one hole I would wonder if it was put in right last time also I would be looking for a part number on dead shaft/axel to make sure it right one for your machine who knows what was done to it in 60 or so years
I thought it was only the later machines with threaded holes to attach the pressing tooling to you pressed them in. The two bolt holes in this D6D final drive are for attaching the tooling to.

20220623_111620-jpg.262361


I remember reading a D7F service manual and it said to flog them in with a hammer (you flog a tool threaded onto the end, not directly onto the threaded end) with someone tightening the inner nut with each blow until a dimension was reached.
 

keith-50

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Joined
Oct 12, 2012
Messages
90
Location
Elgin,TX
I think I have found cause loose adjustment nuts on final drive bearing.I had posted that on dissembly outer holder pulled off by hand, The key way broke allowing support to turn on axle ,support is pinned to inner bearing adjustment collar, there fore backing off bearing preload,, Looks like I need a new axle and holder assembly
 

JEVANS

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Joined
May 7, 2023
Messages
129
Location
AB,Canada
Im also currently working on a D6C, and having issue with the bearing adjuster nut is contacting the guard on the sprocket before Im able to get the Nut tight that holds the holder to the dead shaft. The machine does Not have threaded holes to press the dead shaft in, so we pounded it in. My manual only gives measurements that require the pressing tooling to be installed to make a measurement. Would It be quite easy to pound the dead shaft in way too far? Going by how much threads stick out under the machine compared to the other side’s dead shaft it looks very similar. How to measure it to know of its in the right depth?

Any help is much appreciated.

76A 419 SN.
 
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pittsburgh cat man

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Oct 20, 2024
Messages
123
Location
saltsburg pa
You need to pull the outboard hub off and adj back they are a little confusing they don't turn the way you think they would to tighten the bearing load. first you tighten dead shaft nut at out board hub making sure it is not loading bearings After dead shaft nut is torqued at outboard hub and adjustment nut still turns you can now adj bearing preload. As far as the dead shaft as long as bore in case is not all screwed up it would be pretty hard to go in to far I beleve the old ones told you to have someone tighten inner nut while you sledged shaft till you got to spec I would thing they are the same pressed or sledged
 

JEVANS

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Joined
May 7, 2023
Messages
129
Location
AB,Canada
Thanks for the reply, the problem Im having is as I try to tighten the outer nut down to tighten the hub the adjuster to set bearing preload is essentially getting clamped between the steel wire guard on the sprocket and the hub. So before the outer hub is tight, the bearing adjuster is jammed tight. See pic
 

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