Join Date: Sep 2006
Location: Austin, Texas, USA
I have rebuilt my '85 KRS transmission twice. Found it was cheaper to get a low mileage used unit, which I took apart to make sure it was in good shape. The guy was telling the truth as it was pristine inside- new seals and it is doing good.
What was going wrong was the shift drum, forks, and when it began jumping out of gear, the engagement dogs on the gears. Rebuilds cost $1200 each with me doing the work and using new parts. I found a used K11 trans for $700, plus seals when I took it apart. If you have an early K ('85, possibly '86), the transmission output splines will be different, meaning a later model driveshaft. If the shaft has 80+K miles on it, a change is just insurance.
Just another option for you.
'17 R1200RS, 2 yrs. 27,000 mi.
'16 R1200RS, 18 mo. 28,000 mi. (gone)
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'85 K100/1100RS, 34 yrs. 326,000 mi.
'05 R1200ST, 8 yrs. 57,400 mi.-3rd deer killed it.
'11 R1200RT, 2 yrs. 30,000 mi. (gone)
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'96 Ducati 900SS/SP, 12 yrs. (gone)
500,000+ BMW miles