Brake Disc Sprocket Wear

[Mitchell]

Hi folks. I was cleaning up the idler chains and associated sprockets on my Big Foot the other day, when I noticed sever wear on the right side brake disc double sprocket coming out of the transmission. I do mean sever (see pic). About half the sprocket is worn away from the right (outside) side. The left side the transmission has a little wear in the same way (outside edge of sprocket) but I can live with it. Has anybody experienced the similar wear on the right side, and does any one have an opinion on why this would happen? I bought the machine used with 250 hours on the meter. Also the service manual to replace the brake disc seems pretty straight forward, but I would like to hear from anyone who has gone through this maintenance procedure. Always enjoy your thoughtful replies. Thanks.

[Rock Doctor]

Seen it a couple times. Both times it was due to the idler shaft sprocket being installed backwards.
Same thing could happen if the idler sprocket is locked in the wrong spot ( misaligned ).

I don't lock the idler sprockets down on my machine, letting them float is just fine.

RD

[lewis]

This may help.

[Mitchell]

Thanks for the replies and information. The idler shaft sprocket seems to be installed correctly as per service manual for my serial number of BF, which is with the set screw hole facing outwards towards the outer bearing, minus set screws (for free floating design). The set screws in the outer and inner bearings are not missing, so it seems the idler shaft is not misaligned in or out (baring closer inspection for machined indents on shaft with removal of set screws). However, the sprocket is supposed to be free floating on the spline shaft, which it is definitely not due crud and corrosion. This is probably the source of misalignment between brake disc sprocket and idler sprocket. Thanks for your replies, as they have been very helpful in solving this problem. Now, Back to the varsol bath!

[Mitchell]

Idler axel modification

I have been to some chain maintenance on my BigFoot, and found that the idler chain on the right has been wearing out the brake disc sprocket (earlier post). I suspect the cause is too much travel of the idler sprocket (not stacked to the axel) to the left towards the transmission. Machines manufactured soon after my serial number, had a groove cut in the axle with a retaining ring installed to limit travel of the idler sprocket. In fact the replacement axel for my machine is the newer version of axel. Has anyone with older machines taken the trouble to machine a groove and install retaining rings or otherwise modified (say installing a gear clamp on the axel) the idler axels? Can anyone tell me haw far from the axle end the groove should be? As always, I appreciate any feedback. Thanks

[Slimpickin]

There are set screws in my sprockets. Set the sprocket where you want it. Then use a drill bit smaller than the set screw hole. Drill through the set screw hole into the shaft just enough to make an indent for the set screw to hold on the shaft
The first bearing I changed I didn't get the srocket on the shaft so it lined up with the indent in the shaft. Rather than take it all apart again, thats what I did. So far, so good.

Slim