250 Monza: rear wheel bearing collapsed

[cooperplace]

I'd be grateful for advice re this problem: today luckily right out the front of my house, the bike started making a horrible noise. it turned out that the outboard RHS wheel bearing had completely fallen to bits. It's the bearing outboard of the cush rubber. What was in there was the bushing, the bearing and the circlip. The factory manual shows additional parts that should have been in there: a disc, a felt washer, a cup, and a spacer. None of these were in there. The previous owner bought the bike after it undergone "complete restoration" but I think they left some bits out.

I had been worried about the wheel bearings but I now think that leaving these parts out caused a premature demise of the bearing. It was a FAG bearing, which should be a quality unit.

Any thoughts, anyone? Do these bikes typically have rear wheel bearing problems?

[ducwiz]

Hi,

the wheel hub has it's own two bearings. The bearing mentioned is not a wheel bearing, but it supports the cush drive/sprocket flange. To my knowledge, it is not known for frequent failure. I ran my 350 Desmo (wide-case model) over 20000mls, the bearing never failed.
For the 450 models only, DUCATI used a reinforced version of the flange, including two ball bearings.
If your bearing is a double-sealed type, at least the distance piece 0440.80.410 must be in place. For an open bearing the additional felt ring, washer and cup are mandatory.

cheers Hans

[cooperplace]

Hi,

the wheel hub has it's own two bearings. The bearing mentioned is not a wheel bearing, but it supports the cush drive/sprocket flange. To my knowledge, it is not known for frequent failure. I ran my 350 Desmo (wide-case model) over 20000mls, the bearing never failed.
For the 450 models only, DUCATI used a reinforced version of the flange, including two ball bearings.
If your bearing is a double-sealed type, at least the distance piece 0440.80.410 must be in place. For an open bearing the additional felt ring, washer and cup are mandatory.

cheers Hans

Thanks for the reply, part no. 0440.80.410 was missing. Luckily there was one on Ebay.

[cooperplace]

does anyone know how I get the old bearing outer out of the cush drive body? Just bash it out? heat it up?

[double diamond]

“Bash” is an unfortunate word to use to describe the procedure. Heat the sprocket drive plate to about 250 degrees F. Verify that the circlip that retains the bearing has been removed. After heating the plate, you can spray the race with an inverted can of compressed air used for cleaning computer keyboards. The liquid air in the can is very cold upon discharge and will cool the bearing race, making it easier to remove. Tap the outer race out. Heat the plate, freeze the bearing and reinstall the bearing by pressing on the outer race of the bearing. Install the circlip and seal arrangement. There’s a spacer that slips into the bearing and maintains correct spacing between the sprocket drive plate and the right side wheel bearing in the hub. The part number for this spacer in the catalog is 0440.80.290. If this was missing, it would account for your bearing failure. The .410 number is the outer spacer between the sprocket plate bearing and the swingarm, also necessary. I don’t see how you could properly tighten the rear axle if that spacer was missing. Matt

[Sam]

does anyone know how I get the old bearing outer out of the cush drive body? Just bash it out? heat it up?

If you have an arc welder (stick or mig) run a bead of weld in the inner face of the outer bearing shell when it cools it will contract then fall out. simple

[cooperplace]

does anyone know how I get the old bearing outer out of the cush drive body? Just bash it out? heat it up?

If you have an arc welder (stick or mig) run a bead of weld in the inner face of the outer bearing shell when it cools it will contract then fall out. simple

oh, I like that! I'll try it.

[cooperplace]

does anyone know how I get the old bearing outer out of the cush drive body? Just bash it out? heat it up?

If you have an arc welder (stick or mig) run a bead of weld in the inner face of the outer bearing shell when it cools it will contract then fall out. simple

it worked. Easy. I laid a bead of weld around the inner face, and the bearing shell just tapped out.

Fantastic!

[Sam]

does anyone know how I get the old bearing outer out of the cush drive body? Just bash it out? heat it up?

If you have an arc welder (stick or mig) run a bead of weld in the inner face of the outer bearing shell when it cools it will contract then fall out. simple

it worked. Easy. I laid a bead of weld around the inner face, and the bearing shell just tapped out.

Fantastic!

That was a tip from the late great world sidecar champion 'JOCK TAYLOR'

[cooperplace]

wow, he's been dead a long time: 1982. I saw him at the Isle of Man weeks before he died. He was amazing, he set a lap record. The IOM is incredible. I have no idea how anyone can lap there at >100mph, but he did. Hi time was 108.29 mph.