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Cletrac Tractor Discussion => HG, OC-3, OC-4 & General => Topic started by: Jim Leap on November 01, 2018, 07:25:19 PM



Title: HG track support bushing question
Post by: Jim Leap on November 01, 2018, 07:25:19 PM
Hello everyone,

I am doing a little work on my HG 68 that I rebuilt about 10 years ago. I removed the inner track support brackets to check the bushings because the button fittings had plugged up on both sides on the inside. Surprisingly the bushings are in good shape. The bushings fit rather loosely on the housing stub and in the support bracket. Seems to me like they should be a press fit into the bracket. I am weighing options about how to modify them but wanted to get some expert advice before I proceed. There is an oil groove inside the bracket and a hole in the bushing but if the bushing is loose enough to spin then there is no way for oil to get the the surface between the housing stub and bushing. The bushing can't be a press fit onto the stub since there would be no way to remove it. Any advice or suggestions would be greatly appreciated. The wear on the bracket is on the bottom end which bears the weight so using an oversize bushing is not an option. Not sure if I could find two track support brackets that don't have any wear. I suppose my main question is this: is the bushing supposed to be press fit into the support bracket?

Thanks!


Title: Re: HG track support bushing question
Post by: Robert Barbour on November 04, 2018, 10:30:01 PM
The sleeve is a press fit onto the sub shaft.  They usually wear through on the bottom and split. The support bracket will wear out of round as you say. They can be repaired by boring them out until round again then adding a sleeve to fit.


Title: Re: HG track support bushing question
Post by: mikegt4 on November 06, 2018, 09:53:34 AM
How thick are these bushings? Mine are no more than shim stock thick (maybe .020") and there is a lot of clearance, 1/8" all around.


Title: Re: HG track support bushing question
Post by: Robert Barbour on November 06, 2018, 12:09:25 PM
They are about 1/8" thick. which is not much. There are grease fitting in the support bracket, but most that I have come across have never seen grease.


Title: Re: HG track support bushing question
Post by: Jim Leap on November 07, 2018, 01:01:07 AM
It makes sense to me that the bushings would be a press fit on the stub shaft since there is a grease flow groove cut into the support bracket allowing for lubrication between the support bracket and bushing. There would really be no way for any sort of lubrication be get between the bushing and the stub shaft. I ended up purchasing two slightly used support brackets but I still have the issue of a loose fit on the stub shaft even with new bushings. There has obviously been some wear on the shaft. Landis Zimmerman told me they sometimes build up the shaft with weld and grind it off round so the bushing fits better but he also told me it is not really a press fit to either surface. Making up a shim could work except that the shaft is worn at the bottom and is not "round" anymore.  Any suggestions more than welcome. Seems to be a problem area on these machines.

Jim


Title: Re: HG track support bushing question
Post by: Robert Barbour on November 07, 2018, 12:03:29 PM
The outside part of the stub shaft is cast iron. That does not take weld very well.  I would clean the stub shaft well with a wire brush. Then get some JB weld or similar epoxy and use that to glue the bushing to the shaft.


Title: Re: HG track support bushing question
Post by: Jim Leap on November 07, 2018, 08:12:43 PM
Just bought some fresh JB weld this morning. Seems like the best option to me short of building a special bushing.
Worth a try anyway. Am wondering if I should switch out the button fitting for a standard grease zerk and start using grease on those inside track support bushings as opposed to the 50 weight I use on the other button fittings (rollers, idler, spring and outside track supports).

Thanks,

Jim


Title: Re: HG track support bushing question
Post by: Robert Barbour on November 07, 2018, 09:19:24 PM
Yes. I would use grease there, as there are no seals to hold in oil.


Title: Re: HG track support bushing question
Post by: Jim Leap on November 07, 2018, 11:42:50 PM
The 50 weight seems to be doing a good job of lubricating the outside track support bushings. Wondering if I should switch to grease on those too for the same reason.

Jim


Title: Re: HG track support bushing question
Post by: Jack in NB on November 08, 2018, 05:11:57 AM
Went through three tractors with the problem 30 - 40 years ago.  Built all up with brazing, Machined with fly cutters driven by electric drill for the casting (Pressed out the axle and inserted a stub armature) and drill press and jigs for the brackets. Added grease fittings to the 2 brackets with none on the the front. Not a precise job by any means (lots of holes from insufficient brazing) but hey - they hold grease and stop the flop and toe-in!

And it's likely given the ages they'll outlast the rest of the units - as well as me ! !


Title: Re: HG track support bushing question
Post by: Robert Barbour on November 12, 2018, 02:35:23 PM
Well Jack, that is a lot of work! But it should last a long if kept greased.