Just wondered if anyone has or knows where to get hold of replacement gears for a V50 monza
I think mine has had an issue where a shim may have decomposed and damaged gear 3. I know it is possible to get second hand gear boxes by mine has only done 10K and is like new other than this issue so would prefer to replace the damaged parts. Any comments welcome.
Cheers
martin
Hi,
You may have to resort to purchasing a s/h box if you can’t find any new bits. At least you will have plenty of spares for next time lol.
There are some good people out there able to overhaul your box. It might be worth getting a quote and compare the prices.
Steve
If you can find the part number of the damaged parts try googling Guzzi followed by the 8 digit part number. It usually comes up with a result Teo lamers or Stein Dinse are good places, assuming you have tried Gutsibits.
Thanks Both
I know motocorsa no longer work on older guzzi’s and I hear a lot of good things about NBS or someone up north bearing in mind i’m in cornwall so everywhere is up north. Was planning to do it myself. Gustibits may have second hand parts. Stein Dinse don’t have them listed but I have emailed to check and will try the Teo Lamers as I believe all motomecca’s spares went to them.
Thanks again
Martin
Have you stripped the box down to find out which part is broken as finding a secondhand box might not be as easy as it appears and new parts would be expensive
I have overhauled my own Monza box and they are quite sturdily built, what exactly is your issue
CHRIS P
Monza gearbox has its specific primary ratio - but that’s it - all the rest, all the gears are standard set up shared with all the other gearboxes. What you really need is
- make sure what number of splines on output shaft you got - 10 or 12.
- then find any other gearbox with same number of splines
3)then remove just bellhousing, making an access to primary gearing. Doing so, you do not interfere with secondary shafts and gears. All you need to swap is one pair of primary cogs. Well, by that way you can try to alter your gearing, making your Monza more capable to travel two-up, if you gonna use shorter set of cogs.
Your choices are:
13/24 in V35s
12/24 in V35 III, TT, NTX
13/23 in Imola II
14/23 in V50s
15/22 in MONZA
All the gearboxes for V65 and up have much thicker input (clutch) shaft - no chance to miss the difference. You could use them, but you would need to use corresponding clutch plate at the same time. The idea how to remove abovementioned set of gears can be found in widely accessible Breva 750 manuals. Although in case of slim input shaft(V35s-V50s) you DO NOT NEED to undo the big nut - it will slide through the sealing ring.
Its not quite as simple as getting another V50 gearbox as only the V50/3 will be a direct replacement with a marginal difference in the primary drive ratio (equivalent to 5KpH). The earlier V50/2s had smaller diameter input and output shafts and hence the clutch is different as are many of the internals. The later Mk 11 versions of the Imola and Monza will also be a straight swap but with slightly different gear ratios. If you choose to repair your box then its handy to know that the gear cogs themselves are mega expensive (around $130 each on Harpers site)
Good luck with it whichever way you go
CHRIS P
You might also try Nik’s Bits. 07980 639289. It’s often amazing what he comes up with.
Thanks all
I had been developing an understanding and came up with the Mk111 as a direct replacement option. Knowing that I get would get the same primary drive simply by re-using my original primary drive gear (i) in the manual and main shaft idle gear (57 parts catalogue) which are both fine on my bike is encouraging assuming the splines are the same which by all accounts they should be. Second hand V50 111 boxes seem a little more common than Monza boxes though I am pursuing one at present. new bits are very expensive. One further development. When removing the gear clusters from the end casing I discovered the crimped nut on the end of the shaft behind the bearing had sheered off and was lying in the bearing housing. Can not understand how any of this has happened. Thanks for all the pointers
Huh, I am foreigner and not entirely sure what did you mean “behind the bearing” and “lying in the bearing housing”. But take a look at my working tool, an album of pics from different MG projects happening in my garage
especially at this one, showing primary gearing
and this, showing two different input shafts, V65-up(L) and V35-50(R), together with locking nut:
Can you point out which crimped nut did you mention?