Z-Force drive belt idler

OldMachinist · Jul 22, 2009

I just wanted to share a picture of what happens when the bearing in this idler failed. I have 30 year old Sears tractors that still have the original idlers pulleys on them but the idlers on the machines these days seem to fail early in life. They only put shielded bearings in them which does nothing to keep dust and mosture out. And at least if it wasn't made out of plastic I could have just replaced the bearing. The deck idlers I replaced the bearings with sealed ones when they failed and if the new idler comes in with only a shielded bearing I'll change it to a sealed one before installing. Well I just felt like ranting a little.

J_J · Jul 22, 2009

I don't believe you can replace the bearing in a plastic pulley. I believe it is made as a unit. If the bearing lock up for any reason, the belt will generate enough heat to melt it, and maybe destroying the belt.

OldMachinist · Jul 22, 2009

I know the bearing is molded in place but just like the stamped and riveted steel idlers I put them in the lathe and face off the material holding the bearing from being pressed out. On the steel ones I just press the new bearings in and stake it in a couple of places. On the plastic ones Loctite epoxy holds the new bearing just fine. I've done many of them this way for myself, relatives and friends.

J_J · Jul 22, 2009

OldMachinist ,

I should have known by the name . You have the advantage on most of us. I would just run to the store and hope someone had one in stock.

OldMachinist · Jul 22, 2009

I could also drive up to the farm store and buy a new idler but they get $15-$20 for a new one but I can buy american made sealed replacement bearings for $6.
I think most people with a grinder, bench vise and a couple of large sockets could do it also. That's how I did one a few years back before I had a lathe at home and didn't feel like driving to work on a weekend. You just grind off the lip that holds the bearing in, press out the old one, press in a new one and stake it a few times around the bore. Most of the lawn and garden idlers take a 6203 bearing and I always keep a few around.

JTKub · Jul 23, 2009

Good info OM. Must of made quite the smoke show. How many hours did you get out of that pulley. I've only got 130 something hours & 5 seasons on mine, but I'm always bracing for something. I'm still on the same chewed up pto to deck belt.

Joel

zzvyb6 · Jul 23, 2009

So, do you suppose the bearing went because its hidden under a cover and doesn't get any attention (cleaning or lube)? Or, because it get too much attention from a power washer or air hose nozzle?

I've heard of guys who use hypodermic needles filled with lithium grease to lube the bearings without damaging seals (if they have any). Or would you just squirt some 30w oil on them occasionally?

OldMachinist · Jul 23, 2009

JTKub said:
Good info OM. Must of made quite the smoke show. How many hours did you get out of that pulley.
Joel

I didn't see the show I don't use the Cub for my mowing I use the Allis CA with a Woods belly mower for my part. She uses the Cub for the areas around the houses and buildings and to trim up around the ares I cut so I didn't see the smoke show. I was working in the shop and heard her stop mowing suddenly. The cub has around 275 hours on it. The pulley is in a place thats hidden under the engine mount and doesn't get hit by washing. I think just the fact that they use shielded bearings instead of sealed the the dust eats them up.

OldMachinist · Jul 24, 2009

Update

Normally when I order parts from MTD early in the week I get them in a couple of days but for some reason I didn't get the new idler in this week. So I decided to go ahead and make a new one which is what I was going to do in the first place. I needed to get the Cub out of the shed because I had put it up on jackstands right at the door thinking that the part would be in before I had to work on something else. Well here's what the new one looks like.