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General Category => General Discussion => Topic started by: Guzzidad on December 05, 2018, 07:08:57 PM

Title: First time transmission rebuild
Post by: Guzzidad on December 05, 2018, 07:08:57 PM
   I parked my 96 Sport 14 years ago because it started jumping out of second gear all the time. Now I'm retired and I want to get this bike back on the road. She ran 123,000 miles almost trouble free but I know she has some life left in her. I have no intention of pressing her into full time service but I'ld like to show her off once in a while.
   So I removed the transmission and disassembled it. I found exactly what I suspected. The dogs on the sliding sleeves had rounded off. I had the gears welded up and recut and they look like new. Installed some new bearings and seals. Now, how to install all five shafts into the case at once. Hmmm. So I dug out a copy of a tutorial about transmissions that I printed well over 14 years ago penned by Pete Roper. Everything was perfectly clear and made perfect sense. Went back to the garage and had that transmission back together in about an hour.
   There's still a lot of work to do to bring this beauty back to life but I see the light at the end of the tunnel.
Title: Re: First time transmission rebuild
Post by: guzzi4me on December 05, 2018, 07:13:09 PM
Good "retiree" project!

I for one am glad to have the knowledge of Pete Roper available. His guidance has helped me many times!

Of course there are quite a few others. I thank them all.

Best of luck...you will do fine!

Jeff
Title: Re: First time transmission rebuild
Post by: fotoguzzi on December 05, 2018, 09:05:07 PM
Guzzidad, you are the MAN !
Title: Re: First time transmission rebuild
Post by: andy-gadget on December 05, 2018, 09:38:28 PM
My sport1100 gearbox started making not nice noises years ago, it turned out to be the back output shaft double row bearing polymer cage (the forward row) in many pieces. But further inspection showed the shallow case hardening problem in spalled faces. And the output spline had a broken shaft spline, which I predict you will find as well as it has to do with the clamp type unit mount.

Bottom line was there was little in the box that I would re-use, so I started looking into a more ridable set of ratios rather than the "high first and second, close third, fourth and fifth" nature of the Sport1100 standard box.

After many discussions and careful reading of Guzziology, the Centuro ratios were the ones I decided I wanted, which proved to be useful as the whole box can go in the Sport with no modifications, no boot mount spigot.

A brand new complete box was found in Italy, for much less than a rebuild wound have cost, woohoo.
It was the Centuro silver rather than the sport silver, but Im care not at all for aesthetics, I believe in the form follows function school of thought, one of the many reasons why I don't now and never have, owned a highly dangerous, which is the epitome of function is entirely secondary to form :thewife:

Note the gearbox to crank case colour:
(https://photos.smugmug.com/Motorcycles/Sport-carbies/i-gRDcX6r/0/a1e7021f/X3/IMG_3526-X3.jpg)

Title: Re: First time transmission rebuild
Post by: guzzisteve on December 05, 2018, 10:01:40 PM
Guzzidad, you are the MAN !
I knew He could do it!!
Title: Re: First time transmission rebuild
Post by: Guzzidad on December 05, 2018, 10:27:11 PM
   Thanks Steve. Your advice gave me the tips and confidence I needed.
Title: Re: First time transmission rebuild
Post by: Muzz on December 05, 2018, 10:57:19 PM
Now, how to install all five shafts into the case at once. Hmmm. So I dug out a copy of a tutorial about transmissions that I printed well over 14 years ago penned by Pete Roper. Everything was perfectly clear and made perfect sense. Went back to the garage and had that transmission back together in about an hour.
 

With the smallblock (no Roper tutorials :cry:) I found that tying everything together with a heavyish zip tie worked for me. Guzzi's tutorial was up the Khyber as they quietly changed the pre-selector fork, and what Luigi made look easy suddenly become impossible.
Title: Re: First time transmission rebuild
Post by: pete roper on December 06, 2018, 12:39:23 AM
My sport1100 gearbox started making not nice noises years ago, it turned out to be the back output shaft double row bearing polymer cage (the forward row) in many pieces. But further inspection showed the shallow case hardening problem in spalled faces. And the output spline had a broken shaft spline, which I predict you will find as well as it has to do with the clamp type unit mount.

Bottom line was there was little in the box that I would re-use, so I started looking into a more ridable set of ratios rather than the "high first and second, close third, fourth and fifth" nature of the Sport1100 standard box.

After many discussions and careful reading of Guzziology, the Centuro ratios were the ones I decided I wanted, which proved to be useful as the whole box can go in the Sport with no modifications, no boot mount spigot.

A brand new complete box was found in Italy, for much less than a rebuild wound have cost, woohoo.
It was the Centuro silver rather than the sport silver, but Im care not at all for aesthetics, I believe in the form follows function school of thought, one of the many reasons why I don't now and never have, owned a highly dangerous, which is the epitome of function is entirely secondary to form :thewife:

Note the gearbox to crank case colour:
(https://photos.smugmug.com/Motorcycles/Sport-carbies/i-gRDcX6r/0/a1e7021f/X3/IMG_3526-X3.jpg)

Andy, before you installed it did you replace the 3205ATN9 bearings on the input and output shafts with 14 ball per race AC3's? If not they'll go tits sooner rather than later as well.

Pete
Title: Re: First time transmission rebuild
Post by: lucian on December 06, 2018, 06:01:20 AM
Nice work G.D.  Was the clutch all original ? If so what kind of shape was it in at 123,000?  Just curious.
Title: Re: First time transmission rebuild
Post by: Guzzidad on December 06, 2018, 08:35:16 AM
   Lucian, I'm not going to take the clutch apart just to inspect it. It was working fine when I parked it. It's the third clutch in there. The first failed at 5,000 miles. The friction material separated from the plates. I installed another clutch at 60,000 miles when the throw out bearing failed which also damaged the top hats ( whatever they are called ). I am using a new throw out bearing though.