Wmmayer1973

I picked up a early Ross mt hood and has some play in the crankset.Where can I buy the bearing kit for this?How hard is it to replace?I am a mechanic by trade.

dsbrantjr

Per this ad: https://budgetbicyclectr.com/1987-ro...n-bicycle.html it appears to have a standard square taper bottom bracket. It originally had a serviceable type of bottom bracket but over time it may have been replaced with a cartridge type. The serviceable type can have the bearing balls replaced (if the bearing surfaces are on good condition) and be lubed but the cartridge type must be replaced.
Here are some articles on servicing them:
https://www.sheldonbrown.com/tooltips/cotterless.html
https://www.sheldonbrown.com/tooltips/bbcups.html
https://www.sheldonbrown.com/tooltips/bbadj.html

dedhed

You're either buying loose balls from a bearing house or bike shop and replacing or the common method of measuring existing and replacing the old loose ball setup with a sealed cartridge unit.

https://www.parktool.com/blog/repair-help?area%5B%5D=47

WizardOfBoz

A couple of things. dsbrandtjr found that ad: it shows it originally had a standard solid axle, angular contact bearings with adjustable races, and with the the crank arms attached using a square taper. Regarding that taper, think Morse taper, only square. Be sure to ensure that its really the bearings that are loose, and not the crank arm on the bottom bracket spindle. If the crank arm is loose, I'd bet that the arm is toast - when the arms loosen it takes only a few minutes - or less - of riding to destroy the taper effectiveness. If the arm's loose on the spindle, you need a replacement arm.

If its truly the bearings that are loose, you'll need to start by removing the crank arms properly. You do this with a little tool called a crank puller, which is a little like a bearing puller. Take the caps off the crank arms. There should be bolts holding the arms in place. Remove those. Then the crank puller is screwed into where the cap was, and you can easily remove the crank by turning the crank arm puller. Per the above, please note that if you don't put the cranks back on properly, they'll loosen and wear so that the taper won't hold. This happens rapidly. Go online to find methods to replace the cranks arms - this is important.

You may have the original bearings. If so, there's a lockring (notched locknut) on one side. Loose that with a proper lockring wrench. Then you should be able to remove the bearing cone from that side. Then you can remove the spindle and bearings. They're either loose or in a cage. I'd also pull the cone from the other side, to allow inspection. Being a mechanic, you'll be able to degrease the bearings and races and inspect for wear and/or brinnelling. If they appear good, clean em up and grease them. Put grease or anti-gall on the threads. Install the fixed race with pretty good torque. Then install the adjustable race so that when you tighten the lockring you have no play, and perhaps a little bit of preload. The adjustment, within reasonable limits, has little effect on performance. You want it pretty good, but remember that it's not a 10,000 rpm turbine with 0.00005" runout. No play, with a little bit of common sense preload. You'll be ok.

Alternately, the bottom bracket was replaced with a cartridge unit (sealed bearings in an integral unit). If so, and if the bearings are loose (or if your OEM bearing races and bearings are degraded to an unacceptable extent), find a replacement cartridge and follow the mfrs instructions.

I go through all of this to emphasize the importance of checking the crank arms and replacing them properly. And to note that if you adjust the bearings, your mechanic's experience will likely get you to a preload that's pretty darn (and acceptably) close to correct.

curbtender