Author Topic: Unique transmission bearing question!!!  (Read 4497 times)

Offline NCAmother

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Unique transmission bearing question!!!
« on: February 16, 2015, 01:41:57 PM »
I've been following the really good tutorial on rebuilding the gearbox on the "this old tractor" site.  I have all the case bearings, but what wasn't noted were the pressed on shaft needle bearings for the different gears!  All the bearings feel good  by hand, (but at 7K rpm might be a different story)  Is it common practice to replace these bearings before I assemble the transmission, if so does anyone have any part numbers?  Thanks !
Nate

Offline Wayne Orwig

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Re: Unique transmission bearing question!!!
« Reply #1 on: February 16, 2015, 02:24:06 PM »
The bearings under each gear?
I seldom do anything but look at them. I did have a gear 'explode' in a transmission. I replaced the bearing under that gear on general principal since it had to take a hard hit.
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Vasco DG

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Re: Unique transmission bearing question!!!
« Reply #2 on: February 16, 2015, 02:46:07 PM »
Bit hard to explain but I only replace them if they either look worn or there is excessive 'Rock' in the pinion.

I'm basic terms though they are rarely in need of attention, hence the fact that they are rarely mentioned in write-ups.

Pete

Offline NCAmother

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Re: Unique transmission bearing question!!!
« Reply #3 on: February 16, 2015, 09:21:46 PM »
Thanks fellas,  they feel ok, just wasn't sure if they needed service.

Offline sib

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Re: Unique transmission bearing question!!!
« Reply #4 on: February 17, 2015, 07:49:10 AM »
The 5-speed gearboxes on the recent V7s have only one needle roller bearing, which sits under 5th primary gear.  The Guzzi part number is GU92251028.  It is the only bearing on these bikes that I haven't been able to find a SKF or other equivalent for.  It's the only bearing that's missing from the comprehensive bearing cross reference list at http://guzzitek.org/tableaux_guides/Roulements_Spis_Toriques_MAJ18.pdf  Does anyone here know if there is an SKF or other equivalent bearing for it?

Not that I immediately need one, but I'm curious about why it seems to be so obscure.
Current: 2021 V7 Stone E5
Previous: 2016 V7II Stone
Previous: 2013 V7 Stone
Several decades ago: 1962? Honda CB77 Super Hawk

ksd124

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Re: Unique transmission bearing question!!!
« Reply #5 on: March 05, 2015, 09:19:37 PM »
Forgive me for jumping on the tail of this thread (please tell me if it’s not etiquette), but its subject matter matches very closely with what I am currently dealing with.  Perhaps a familiar story, but engine & gearbox (T3) are out to replace engine seals, so thought I’d utilise Pete Roper’s guide to minimise the brick-in-a-bucket syndrome of the gearbox.  Upon lifting shafts from box, torrington thrust bearing separated into 30 pieces (29 rollers - one missing completely - and the cage).  That got me questioning the other bearings.  Double row and other case bearings seem reasonable, but I’ve decided to change anyway.  There does, however, seem to be a fair bit of play in some of the pinion bearings.  5th, on the cluster shaft, in particular - which I estimate rocks by about 2mm at the outer edge of the gear.  I assume this is excessive?  I assume also (subject to there being no major visible wear), that I wont need to change the inner sleeve these run on - just the needle bearings themselves?

Any input would be most welcome and, in case you’re listening, thanks to Pete and John for your guides - they’re fantastic and very much appreciated.

Offline Muzz

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Re: Unique transmission bearing question!!!
« Reply #6 on: March 06, 2015, 12:22:50 PM »
The 5-speed gearboxes on the recent V7s have only one needle roller bearing, which sits under 5th primary gear.  The Guzzi part number is GU92251028.  It is the only bearing on these bikes that I haven't been able to find a SKF or other equivalent for.  It's the only bearing that's missing from the comprehensive bearing cross reference list at http://guzzitek.org/tableaux_guides/Roulements_Spis_Toriques_MAJ18.pdf  Does anyone here know if there is an SKF or other equivalent bearing for it?

Not that I immediately need one, but I'm curious about why it seems to be so obscure.

When my 5th gear hardening went south in the middle of a longish tour, that bearing (along with the rest from the hardened steel dust) pitted the rollers in that bearing and damaged the shaft.

I was off the road for over a year. There is no equivalent. :'( :'( :'( On the Stein Dintze site they also do not list an alternative. They were out of stock at the time. Pete R tried to get one but no go.  Pfaff on the site here saw when they actually came back in and whipped one over. I don't know who actually make it.  Could be like many of the Honda bearings where you can only buy from a Honda dealer; bearing suppliers are not actually allowed to sell them.
Muzz. Cristchurch, New Zealand
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