I just did a similar task to a new-to-me Max IV. It was well worth the time and money to take the frame out, de-rustify it, weld a few spots, paint it and then replace all the bearings/collars etc. When I bought it, it appeared that it had never really been maintained- chains were shot and had been run out of alignment. This also caused damaging wear to a sprocket and tensioners. The bearings appeared good (and they ended up being good when I removed them), but I figured I'd replace them while I was refurbishing the whole unit. There was about 3 inches of grease, leaves, twigs, shotgun shells, electrical butt connectors, an old spark plug and various other items in the tub. I highly recommend (my local dealer suggested this) that you add "L" brackets to the rear part of the frame to strengthen the t20 mount. There are photos below that show the brackets and where I had to weld some cracks (the brackets should prevent future cracking).
12 bearings w/ collars, entire new set of chains, 1 rear sprocket, 1 new/used axle (to replace one that was bent when I bought it), 2 new solid (not pressed) tensioners, and 6 new zerk-fitted inner bearing carriers totaled about $1200. My time is priceless with new twins, but I managed to get it done in time for the Alaska caribou and moose seasons!!
I already mentioned this on another thread but "Mike" is a helluva help on this kinda stuff and the video is truly priceless. I'm going to try to add some photos here to show what I did.
A buddy and I are also building a new aluminum roll cage/enclosure to replace the tube steel one that came on it. I will try to post some photos of that as well in the future.
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