Rear wheel bearings

#1
I pulled the wheels off my mtd trail flite to get ready to replace the tires, tubes, and bearings. The front wheel makes sense to me, but the rear had no seals or covers or snap rings. When I took the axle bolt out, a dozen or so balls fell out, but there were no other bearing IMG_20240710_143907229.jpg IMG_20240710_143907229.jpg parts besides the two metal cups in my picture. What do I need to buy to put new bearings in? I'm confused... At the least I think I need a spacer to go on the axle, between the new bearings. I doubt there's a parts diagram, but if anyone has any info or photos, let me know please!
 

pomfish

Well-Known Member
#2
MTD made bicycles as well and this is a bicycle style bearing set up. Stupid I know but it's what they did.
Take some of the bearings you didn't lose and go to an old bike shop if possible. Worked for me when I had the same thing happen.
I didn't lose that many but enough that had to get some. When they are properly packed with grease they stay in place but you are dealing with a 50 year old bike.
The ones that were already missing were chewed up into small bits and got past the cups. No grease = heat, etc.
HTH
 
#3
Finding a bicycle shop nearby is going to be pretty tough. I'm in the middle of nowhere, about a half hour from a town of 1600 people. I can order parts and pick them up at the post office though. Am I understanding correctly that I can pack it full of loose ball bearings and grease when I reassemble? The metal cups keep everything contained ? Or did the shell of the original bearings disintegrate over time?
 
#4
I will advise you to follow the advice from @pomfish . It makes sense.
While you are waiting, what is the inside diameter of the hole in the wheel? What is the diameter of the axle bolt?
Maybe there is a sealed bearing that you can push in there to avoid this problem in the future.

I have several big old school bike shops in my little town if you need my help.
 
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pomfish

Well-Known Member
#5
As memory serves it just uses those cups and Acorn Nuts on the axle, there was no dust cap like a sealed bearing has.
My MTD is in storage right now so can not go look.
Kinda think there might be a workaround to modern bearing deal but may involve also changing out axle?
They are strange that's for sure.
 
#10
I had the same problem when I pulled mine apart a couple months ago, I pulled the wheels apart outside on the tailgate of a pick up truck and the ball bearings went everywhere in the bed of the truck and I didn't round them up right away and unexpectedly sold the truck the next day and sold my BALLS with it??? I found a couple and was able to measure and order these, I'll be repacking mine in the next week or so when I start putting the bike back together, here is what you need , I forgot the number needed I think maybe 16-18 each side, I need enough for the front and back which leaves about half, you can order some yourself or I will send you what you'll need if you want?
 

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#12
Thanks minbikefever! Strange, the front and rear wheels have different size openings. The cups for the rear are too small to fit tight in the front. That's ok with me, because the front wheel had two traditional bearings with a spacer between them. I need to find my calipers (in a box somewhere from moving). Hopefully the axle/bearing hole isn't worn out, it was slightly bell shaped, not a straight cylinder. I just ordered new tires and tubes :(
 
#13
Front wheel pic with normal axle, bearings, spacer. Not pictured: wayyy too many washers and nuts haha. The guy who sold it to me was known as the kind of guy to not spend an extra penny on repairs for his truck. It seems he learned his craft on this bike . IMG_20240711_131925833.jpg IMG_20240711_132016934.jpg
 
#14
Rear wheel is an odd size to me... Axle bolt is .525 inches, at the smooth part, but the threads are taller. Not going to be easy to get a 1/2 inch ID bearing on there. OD looks like 1 1/4 . Looks like I have to go with the loose ball bearings, unless someone has an idea. IMG_20240711_140357558.jpg IMG_20240711_140405974.jpg IMG_20240711_140231223.jpg IMG_20240711_140310742.jpg
 
#17
I believe those axle nuts are tapered to better support the "cups". They have a thin nut that goes on top to lock them in place. I think It's not rusty in that area because it's in tight contact with the cups, and I poorly/quickly hand sanded all the parts as I removed them. I could be wrong, I'm just guessing
 
#18
I can't find 1.25 od x .5 id bearings online. I might try 13mm x 32mm, but I'm pretty sure it won't work. I'm going to wait to see if minibikefever can post a picture of him inserting and greasing his loose bearings.
 
#20
I can't find 1.25 od x .5 id bearings online. I might try 13mm x 32mm, but I'm pretty sure it won't work. I'm going to wait to see if minibikefever can post a picture of him inserting and greasing his loose bearings.
I'll try to pack those bearings this weekend if that will help and grab pictures, And I'm not 100% sure but I may have a front wheel axle with the tapered nuts and cups, I will have to look, I sold the wheels awhile back but thought I kept the axles???
 
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