bevel box bearing

[Guest eddy]

hello

in the bevel box on the swingarm side there is a small needle bearing in the housing it is fixed there it is also a open bearing

i fail to see what that bearings pupose is the only thing passing through there is the axel that fixes the rear wheel it cant be turning the axel and the bevel box are fixet points so what is the point ?now it is a rusty bit of scrap so what is its purpose?

gr ed

[Guest ratchethack]

Eddy, its purpose is to allow the bevel box to "float" in the parallelogram formed by the swingarm on the bottom, the torsion beam on top, the bevel box at the rear, and the chassis at the front. This configuration allows the bike to accelerate without the tendency of the chassis to "jack" under torque loads with the force of the pinion gear "climbing" the crownwheel gear. Works pretty well, at that.

 

The needle bearing you refer to is small, because it only has to handle the "back and forth" rocking motion of the bevel box relative to the spindle as the rear suspension works through its range of motion. The bearing is normally protected by a flat washer between the bevel box and swingarm that fits into a neoprene recess pressed into the outboard of the bevel box casting. This flat washer seems to get lost quite often. The bearing is notorious for failing due to lack of lube and water intrusion from neglect of proper maintenance, particularly when the washer isn't present. This bearing is properly kept greased (I use boat trailer wheel bearing grease for its superior resistance to water intrusion) whenever a rear tire is changed.

 

It's not all that critical to have it fail, as it isn't nearly as important as a wheel bearing, for example. But not too costly to replace, and should be done after a proper clean-up, of course.

 

Hope this helps.

 

EDIT: FWIW, you can just see the flat washer between the bevel box and swingarm if it's there. By my measure with a caliper, it's ~41 mm OD.

[Guest eddy]

thank you

mayby its wise to drop the bearing and make up a bronze bushing no more rust

gr ed

[Guest ratchethack]

thank you

mayby its wise to drop the bearing and make up a bronze bushing no more rust

gr ed

This has been proposed before. I don't know that anyone's actually done it, but I don't see any problem.

[Skeeve]

thank you

mayby its wise to drop the bearing and make up a bronze bushing no more rust

gr ed

 

Maybe use Oilite [or whatever that sintered bronze stuff is called that specially developed for low pressure, inaccessible bearings...]?

[Guest eddy]

made one up today and drilled a small hole for a grease nippel in the bevel box on the bottom side ,i have to grease the shaft anyway i made the bush shrink fit so it stays in place the grease nippel locks it also looks as it might work made the bush from the same material as i use for propulsion bearings in boats [excuse the english i am dutch]

gr ed

[Skeeve]

made one up today and drilled a small hole for a grease nippel in the bevel box on the bottom side ,i have to grease the shaft anyway i made the bush shrink fit so it stays in place the grease nippel locks it also looks as it might work made the bush from the same material as i use for propulsion bearings in boats [excuse the english i am dutch]

gr ed

 

Your English is fine, it's your punctuation that needs help!

 

Please let us know how your experiment plays out. Pics of your installation would be nice too. Keep up the good work!

[Lamedog]

I've had the darndest luck with the simplest problems. My new needle bearing and inner race finally arrived. I'd planned to punch the old needle bearing out from the inner side of the bevel-box. With the drive removed from the bike, the stack inside the drive housing is loose enough to allow the spacer slide a bit so I can get a purchase for the punch. A couple easy taps didn't do the job and I don't want to use any more force until I'm positive I'm not driving against a fixed part (esp. a cast part of the box housing). The figure in the '02 Guzzi parts catalog "D3" is unclear and the manual isn't helpful.

 

Any tips on removing the needle bearing? (or I'm off to borrow a blind bearing puller....).

[belfastguzzi]

Some people have had a lot of difficulty getting this out. Some others have found it to 'slide' out easily.

I, of course, had great trouble with it and a MG mechanic in England who I spoke to said that they are often difficult. He dremels them.

 

See the posts here for previous woes, warnings and solutions:

(watch-out for that captive washer)

 

http://www.v11lemans.com/forums/index.php?...ost&p=48465

 

 

http://www.v11lemans.com/forums/index.php?...ost&p=49022

 

http://www.v11lemans.com/forums/index.php?...ost&p=50054

 

 

more in this thread:

http://www.v11lemans.com/forums/index.php?...ost&p=49457

[Lamedog]

Thanks. Surprised I didn't find the threads. Your work is definitive - just not the answer I'd hoped for. Oh well, I'll stock up on beer and expect it to spend some time at it.

[belfastguzzi]

Oh well, I'll stock up on beer and ...

...heavy hammer, drill, dremel, axe

and more beer

[badmotogoozer]

...heavy hammer, drill, dremel, axe

and more beer

 

I find this solid advice can be applied to nearly all of life's problems. With the exception of alcoholism.