1980 Max IV restoration

[hornellfirefighter61]

Well after many years on hold I'm finally going to start work again on my 1980 Max IV serial #6448. Years ago I removed the frame from the body doing so I had to cut the original axles, two (2) of which were bent anyways. I'll need to source or fab new axles. I'm going to replace all the bearings on flanges, currently the outer bearings are the 62mm size, does anyone now if I can upgrade them to the beefier 72mm size or do I have to stick to the 62mm size? While i have to frame out I'm going to measurements and use the frame as a template to make full length outer rails w/ integrated plow mounts. I plan to do the T20 split shift mod, replace the front bench seat w/ a single suspension seat and reinforce / beef up the frame side of the rear hitch. Once the frame is back in the body and the body halves are together I'm going to fabricate a body band w/ winch mount. Any other mods or changes that I should consider during my restoration?

Thanks,
Mike

[AndyL]

You would have to modify the chassis to accept 72mm outer bearings. You will probably want to stick with the 62mm. We have them available at www.maxatvs.com/store.

[hornellfirefighter61]

Modify as in how? Is the bolt pattern the same? If so would it just require increasing the size of the hole to accept the bearing? I'd like to add bearing cages too to be able to run tracks safely, but I can only find bearing cages that work with the 72mm bearings.
Thanks,
Mike

[AndyL]

Modify as in how? Is the bolt pattern the same? If so would it just require increasing the size of the hole to accept the bearing? I'd like to add bearing cages too to be able to run tracks safely, but I can only find bearing cages that work with the 72mm bearings.
Thanks,
Mike

Bolt holes are spaced differently as the 72mm flange is ~3/8" larger in outer diameter. Of course the ID is larger too since we're talking 72mm vs 62mm bearings. The bearing holes in your chassis are cut for 62mm. You would have to enlarge each hole to accommodate a 72mm bearing, and re-drill holes for the bolts. And you'd have to cover up the holes that are already there.

Why don't you want 62mm bearings? Even know the 72mm's are larger/stronger, they ran 62mm bearings for 30 years, and many of those machines are still being used today. Maintenance is key more than anything else.

Requiring bearing cages, we only make them for 72mm out bearings unfortunately. The old 62mm bearing cages haven't been made for new machines since the mid 1990s.

[hornellfirefighter61]

The ability to run bearing cages for strength with tracks is the main reason. I guess I'd have to weigh my options, modify my frame while I have it out to accept the 72mm bearings vs fabricate costum bearing cages to work with the 62mm bearings.
Thanks,
Mike