5 Speed Main Shaft Thrust Bearing Cross Reference

[jwinwi]

Starting with 850T (?)  5 speeds use Guzzi PN 9225 8525 in front of the main shaft; it is a flat needle bearing/thrust bearing with 2 hardened races/washers. Following is the cross-reference info:

Bearing
OD: 42 mm
ID: 25 mm
Height: 2 mm
McMaster Carr PN: 5909K16

(2) Races
OD:42 mm
ID:25 mm
Height: 1 mm
McMaster Carr PN: 5909K76

Didn't find this info listed on Greg Bender's site so I'm guessing it's rare to have to replace this bearing but the one in my 96 Sport 1100's transmission lost all its rollers when the Main Shaft was removed.

[80CX100]

Starting with 850T (?)  5 speeds use Guzzi PN 9225 8525 which is a flat needle bearing/thrust bearing with 2 hardened races/washers. Following is the cross-reference info:

Bearing
OD: 42 mm
ID: 25 mm
Height:

Tks very much for posting that info, it may come in very useful 

Kelly

[jwinwi]

Tks very much for posting that info, it may come in very useful 

Kelly

You're welcome Kelly. Even more useful after I added all the info... I posted that first bit by mistake while I was still typing.

[Old Jock]

Very useful thanks for that

[jwinwi]

Very useful thanks for that

John, thank you for posting your Gearbox rebuild article. VERY useful as this is my first attempt at Gearbox rebuilding. Pete Roper's article on shimming the shift drum was tremendously helpful as well. 

[sib]

Seems like Harpers has them for $23.23.

[Old Jock]

John, thank you for posting your Gearbox rebuild article. VERY useful as this is my first attempt at Gearbox rebuilding. Pete Roper's article on shimming the shift drum was tremendously helpful as well. 

Glad it was of some use and my pleasure 

I am not fit to clean Professori Roper's boots.

I found Pete's write up excellent but a little lacking in detail for us mere mortals. When a buddy came around to help me strip the LM 1000 box he suggested perhaps an article could come out of it and as usual I overdid it. That said it's useful for somebody who has never been inside and gives anybody an idea of what they are getting into

Thank You for your kind words and sentiments, appreciated

[LesP]

It is a part that can be of varying quality along with the clutch push rod thrust bearings so might be a case of brand name cautious. (I replaced it in the G5 clusters I used)
I ended up with three of the later and one had fallen to bits in transit.

With the (after) shimming I checked the corresponding gears for equal dog depth engagement by having a look with a bore-scope.

[jwinwi]

It is a part that can be of varying quality along with the clutch push rod thrust bearings so might be a case of brand name cautious. (I replaced it in the G5 clusters I used)
I ended up with three of the later and one had fallen to bits in transit.

With the (after) shimming I checked the corresponding gears for equal dog depth engagement by having a look with a bore-scope.

According to the labels on the bags, the bearing I got was made in Germany, the races made in Slovakia for about 1/3 of Harper's price. No offense to Harper's intended. I wonder where the Guzzi OEM part is made these days... Since Piaggio took over fewer and fewer parts have been made in Europe.

[John A]

Where would I find your gearbox writing?  I like to print this stuff and put someplace safe so I can’t find it later

[Old Jock]

Where would I find your gearbox writing?  I like to print this stuff and put someplace safe so I can’t find it later

John you referring to the one I did?

It's on the Guzzitech.dk site hosted by Gregg Bender under Technical The Complex Stuff

Here is a link to that area, there is a lot of great stuff on there (& I don't mean my write up) the engine rebuild by Pete and the Gbx shimming also by Pete are recommended, my write up is Gearbox rebuilding - with pictures, jeez it's incredible to think that nearly 9 years have past since I did it

http://www.thisoldtractor.com/guzzitech.dk/gb_en_complex-technical.htm

Hope that helps

John

[John A]

Thanks,  I  haven’t been to that site since a hard drive failure a few years ago. 

[acogoff]

     I have found that the mcmaster thruster and races are of equal quality to the stock, or they may even be the exact same parts. It is also important that your mainshaft end float be checked to not to be too excessive. I have a box on my bench right now where a self appointed "mechanic" had installed a bogus end shim that was at least .030 inch too thin and a whole lot of slamming back and forth had occurred. The bevel gears are very tough and I could see no problems with them, but the 5th gear shifter fork had extreme wear on the pin that rides in the drum. The thing must have had to be forced into gear, or maybe even held there. Guzzi has about 4 thicknesses of end shims listed. For me, .005 to .012 inch mainshaft end float seems to work. Getting the drum and this shaft properly shimmed will make for a way better shifting and trouble free box.

[jwinwi]

     I have found that the mcmaster thruster and races are of equal quality to the stock, or they may even be the exact same parts. It is also important that your mainshaft end float be checked to not to be too excessive. I have a box on my bench right now where a self appointed "mechanic" had installed a bogus end shim that was at least .030 inch too thin and a whole lot of slamming back and forth had occurred. The bevel gears are very tough and I could see no problems with them, but the 5th gear shifter fork had extreme wear on the pin that rides in the drum. The thing must have had to be forced into gear, or maybe even held there. Guzzi has about 4 thicknesses of end shims listed. For me, .005 to .012 inch mainshaft end float seems to work. Getting the drum and this shaft properly shimmed will make for a way better shifting and trouble free box.

Thank you for this info! Guessing that incorrect Main Shaft End Float is what caused all the rollers to fall out of my original bearing when the shaft was removed from the transmission. I will be transplanting all the gears and shafts from a Helical gearbox and will check the Main Shaft for length and shim it properly.