900SS GEAR SELECTION

If you need technical information or help with your early crossover gearchange squarecase Ducati 860/900 engine - post your FAQs, comments & questions here.
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Kill2eat
Cucciolo - the Lil Pup
Posts: 2
Joined: Sat Dec 27, 2008 9:10 pm

900SS GEAR SELECTION

Post by Kill2eat »

I have a 1976 900SS. On my last 400km ride I lost 1st gear. I played arround with the adjustment to the gear selector but to no avail. I have even changed over spocket cover with gear selector as I had a spare, but I still have lost 1st. I have a false neutral. The gear selector spring seems to work fine. Does anyone have any clues here?
wdietz186
Cagiva Alazzura
Posts: 707
Joined: Sun Sep 10, 2006 5:40 pm

Post by wdietz186 »

Your description sounds like a shift fork or a dog problem. The good news is that the bike is certainly worth fixing. The bad news is the cases need to be split. Just to make sure pull the selecter box off and turn the shift drum shaft counterclockwise until it stops, You may have to spin the rear wheel a bit to get the gears to engage. If the wheel stops you have engaged 1st gear, If you try to spin the wheel backwards it should also lock. If the dogs are worn or broken the wheel can break free if the wheel is moved back and forth. I had the same problem with my 77 SS it turned out the shift dogs were rounded off due to excessive end play in the transmission shafts as set up from the factory. It started with it jumping out of gear occasionally and progressed to no engagement at all.
Lumpy
SD900 Darmah
Posts: 329
Joined: Sun Mar 25, 2007 5:49 am

1st gear

Post by Lumpy »

Can you engage 1st gear with the selector box removed using an adjustable spanner? I`ve found those selector units to be finicky little fellers. Be sure it`s not in there before you split her open.
Kill2eat
Cucciolo - the Lil Pup
Posts: 2
Joined: Sat Dec 27, 2008 9:10 pm

Post by Kill2eat »

Thanks to both of you for replying. If I stick a big screw driver in the gear shaft coming out of the case and move the wheel backwards and forwards I am pretty sure that I can get all 5 gears. The shaft rotates about 270 between 1st and 5th if I am correct. Ist gear being clockwise.

This loss of 1st gear was a sudden problem, I was not having issues gears slipping out. After taking the sprocket cover off and removing the selector mechanism I noticed that the adjustment screw and nut were lose ( that would be right). I tightened it and replaced it but I still had the problem. I noticed that the return spring looked slightly bent. I had another complete cover and mechanism with what appears to be a good spring, but again to no avail. I will give it another attempt tomorrow and maybe get a new spring if Gowenlochs are open. I had one sent to me but it was for a later model.
ozihotrod
Mariana
Posts: 48
Joined: Mon Oct 06, 2008 4:46 am

Post by ozihotrod »

Is your bike the model which had the first left hand gear change set up fitted. If so you may find that the cross over shafts are worn on the tongue and grooves were they fitted into each other. Notonight68 had the same trouble with his 76SS , he made his own new parts and repaired the problem, you may find some info on how he did it in one of his many interesting posts.
from little things -big things grow
duerosso
Cucciolo - the Lil Pup
Posts: 2
Joined: Sat Nov 27, 2004 12:42 pm

Post by duerosso »

Are You aware that the adjustingbolt has an excentric backside ?
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