The other day my ‘74 R75/6 got stuck in 3rd or 4th gear. Clutch works and shifter moves up and down but no gear change happens. Despite its low miles it has always been a bit fussy. It has a fondness for false neutral and is stubborn about going into first at stoplights when impatient drivers are behind me. I want to fix it but am also considering trying a later-model transmission. I am having trouble finding one though and am not completely sure which ones will work. Any tips or advice would be appreciated. EBay has some sketchy ones, Craigslist and Marketplace don't seem to have any.
Take Care, Rob
What you have there is a broken pawl spring in the shift mechanism. The '74 transmissions have a reputation for this particular issue. If you were to get your transmission rebuilt, the current updated shift kit would help with your shifting issues. With regard to swapping out your transmission, you are limited to pre-1980 model years. An incompatible transmission can be identified by the clutch release arm and the casting characteristics of the rear cover. Your transmission has a pivot pin and a circlip where the release arm is fitted. Later transmissions have a thru bolt and a nylock nut for the clutch arm pivot. These changes are associated with the change from a heavy flywheel to the lighter clutch carrier. Any early transmission will fit, including a 4 speed from a /5. If you fit a later transmission, it will bolt up ( I've seen it dine), but the clutch release mechanism does not have the leverage necessary to compress the clutch spring diaphragm of the early flywheel models. There is also and issue with the input shaft spline and the clutch push rod with respect to the depth of the input shaft interface in the early clutch driven disc.
former Airmarshal, IL.
@8053 you are awesome and I appreciate you taking the time to respond to my post. I am still trying to decide what route to go in, but I miss riding the bike. Your advice helps me in making my decision.
Take Care,
Rob
You did not give your location, but in the mid-west, the Indiana Airmarshal, Don Beverage is competent working inside a transmission. Somewhere on this website is a list of "airhead friendly shops." You might find some guidance using that resource. That list is clickable under the heading titled "ABOUT" at the top of the page.
former Airmarshal, IL.
I will check that out. I am in Longmont Colorado. Thanks again for the help.
Rob
The newer 80 or 81 to 95 Transmissions can be mounted on the back of the older bikes. But, it is an enormous pain in the butt and expensive to do so.
James is correct, the early five speed transmissions did have problems that did get sorted out with the fixes he suggests.
Good luck.St.
Beware! I do not suffer fools gladly! St.
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