I've got a loose dead axle on one final drive. By marking the position of the outer hub and checking it I can see that the axle has turned some a couple of times. The last time I had it worked on it was very marginal on the taper so they tack welded the inner end of the axle to the case in hopes of keeping it from moving. The weld didn't hold and now I'm back to figuring out a repair.

The good way to fix it is to bore out the case and put in a bushing to renew the taper. I talked with Cat a while back, and to make a bushing, bore it, and install was quoted at $8,500....ouch.
Rather than have them do all the work, I thought I'd use a local independent shop, make up the bushings myself, and have Cat come out and just do the bore.
Well, that'd be fine but Cat doesn't have the bushing and won't let loose with any info on the bushing itself.

Does anyone out there know of a source for the bushings, made up their own bushings, or have dimensions for the ones Cat used to supply? Short of getting a new dead axle, taking measurements from it, and making up my own bushing I'm not sure where to go from here.

Edit: If I knew how far the axle is normally pressed in after it contacts the taper I could probably come up with a bushing on my own. The thickness of the bushing would be dependent on the taper angle and wouldn't be extremely critical.
Did the bushings have just a straight outside diameter that was designed to bottom out in the bored out hole?

Here is a link to my D4 repair that may be of some use to you.
www.acmoc.org/bb/showthread.php?25802-Problems&highlight=

If you can find an older engineering shop with portable lineboring gear and somebody that knows what they are doing its not too difficult and a hell of a lot cheaper than cat.
They made the sleeve using the outer most tolerence on the distance the shaft needs to be pressed in to, if that makes sense.
Aftermarket dead axles from CTP are relatively inexpensive.

EddieB has the info with sleeve specs for this but it is for the older 8/9u series with different dead axle. But the basic idea is the same, just need to do your own measuring, unless you have better luck getting some technical info from cat than I did.

"Glum" wrote:

Here is a link to my D4 repair that may be of some use to you.
www.acmoc.org/bb/showthread.php?25802-Problems&highlight=

If you can find an older engineering shop with portablelineboring gear and somebody that knows what they are doing its not too much difficult and a hell of a lot cheaper than cat.
They made the sleeve using the outer most tolerence on the distance the shaft needs to be pressed in to, if that makes sense.
Aftermarket dead axles from CTP are relatively inexpensive.

EddieB has the info with sleeve specs for this but it is for the older 8/9u series with different dead axle. But the basic idea is the same, just need to do your own measuring, unless you have better luck getting some technical info from cat than I did.

Looked at your link...good info. I actually have an automotive boring bar similar to the one that was used on your machine. Might be able to rig it like that and get it done.
If I understand you correct, you made the bushing so the axle would sit at the max length distance when installed by hand. I might go just a bit tighter just to be sure it didn't press in too far.

Yes, aim for the maximum distance possible. Remember that there are three taper fits on these cat final drives, which can create quite a track alignment problem when they stack up.
As a side note, my D4E has done just shy of 2000 hours since that work and appears to be holding up well.

Shame you are not in mt, I fixed a lot of then for cat, hole is straight bored 3/8 to 5/8 oversize. new bushing made from 4140 with a recessed shoulder on the lathe ( so the bushing cant fall in.) fit .005/10 tight, froze with liquid n2. Taper would be machined oversize to match the fit into the tractor frame. We would freeze the dead ax with the n2 as well and pressed it lightly in, the shrink fit would do all the work. the hard part was the removal of the track parts and final drive and also setting the boring bar square.....WA7OPY

Hi Team,
in answer to a PM here should be a link to the above repair we did many times over many years for all size machines using Tapered Fit Sprocket Shafts.

www.acmoc.org/bb/showthread.php?22193-Co...4&highlight=bulletin

Hope this helps, along with data supplied above or keep asking questions.

Edit,
I should also add that the dimensions given are for machines back to pre-mid. 1950's.
From memory, I think some machines axle sizes went up one size of machine.
You will need to use this as a method guide but you may find a machine size data that suits also.

Edit 2,
getting the rear face flat and square was the biggest problem with the rig shown here--this is what we used--so as the split sleeve could butt up against it and not move due to contacting ridges and grooves that might compress in severe use.
Using the engine cylinder borer was used to until it died then we resorted back to the Cat Boring rig, I think with a clamped on sleeve on the bar to act as a consistent stop point for the tool.
I guess your experience may be different with the equipment available.
Been a few years now and a lot of other experiences to confuse things.

Cheers,
Eddie B.