So, just got the gearbox stabbed back into the '98 RT and here's what I think so far (main failure on this bike which has 280K miles on it was the throwout bearing):
- The clutch rod when being engaged moves forward to contact the diaphragm spring which then pushes the diaphragm spring away from the front half of the clutch disc pressure plate assembly which then allows the disc to spin between the two pressure plates. The rod rotates with the diaphragm spring which moves with the flywheel. The aft end of the rod fits into a bearing which is on one end of the throw out bearing assembly.
- The throw out bearing assembly is a cylinder with the the bearing on the front end and metal puck on the aft end. The whole thing moves fore and aft in a matching female cavity cast into the transmission. There is a spring which fits into the throw out bearing at the back followed by the rubber boot which keeps the puck exposed to contact the adjuster bolt in the actuator arm. The system is designed so that the throw out bearing pulls the clutch rod away from the diaphragm spring until it is pushed forward.
- The original throw out bearing was plastic, replacements are metal.
- I would replace the throw out bearing and clean/lube the cylinder it rides in at some interval but every other spline lube for sure. The failure mode of this part on this bike is total inability to use the clutch. Its a $35 part.
- The manual calls for lubrication of the diaphragm spring at the contact points to the front as well as at the drive plate where it contacts the main part of the spring. I did this on this repair.
- With a new throw out bearing and all parts of the system lubricated and adjusted properly the effort to engage the system is amazing low. I can tell immediately that there is a bit more friction in the '99 which is my daily driver. I am going to replace the throw out bearing in that to see if it the cause (not moving freely in the cylinder.
- At 280K miles all the parts of the assembly looked fine and I reused them except for a new disc. I compared all parts to a new assembly I had for this project but am now saving. I de-glazed the pressure plates and cleaned/lubed the spring. I will report on the end result on the road. The old parts looked just fine to me.
- Btw you can stab this transmission back into the bike without guide pins. Just used a small floor jack but you do have to pry up the battery/ABS tray quite forcefully to get the first/last inch or thereabouts.
- The clutch rod when being engaged moves forward to contact the diaphragm spring which then pushes the diaphragm spring away from the front half of the clutch disc pressure plate assembly which then allows the disc to spin between the two pressure plates. The rod rotates with the diaphragm spring which moves with the flywheel. The aft end of the rod fits into a bearing which is on one end of the throw out bearing assembly.
- The throw out bearing assembly is a cylinder with the the bearing on the front end and metal puck on the aft end. The whole thing moves fore and aft in a matching female cavity cast into the transmission. There is a spring which fits into the throw out bearing at the back followed by the rubber boot which keeps the puck exposed to contact the adjuster bolt in the actuator arm. The system is designed so that the throw out bearing pulls the clutch rod away from the diaphragm spring until it is pushed forward.
- The original throw out bearing was plastic, replacements are metal.
- I would replace the throw out bearing and clean/lube the cylinder it rides in at some interval but every other spline lube for sure. The failure mode of this part on this bike is total inability to use the clutch. Its a $35 part.
- The manual calls for lubrication of the diaphragm spring at the contact points to the front as well as at the drive plate where it contacts the main part of the spring. I did this on this repair.
- With a new throw out bearing and all parts of the system lubricated and adjusted properly the effort to engage the system is amazing low. I can tell immediately that there is a bit more friction in the '99 which is my daily driver. I am going to replace the throw out bearing in that to see if it the cause (not moving freely in the cylinder.
- At 280K miles all the parts of the assembly looked fine and I reused them except for a new disc. I compared all parts to a new assembly I had for this project but am now saving. I de-glazed the pressure plates and cleaned/lubed the spring. I will report on the end result on the road. The old parts looked just fine to me.
- Btw you can stab this transmission back into the bike without guide pins. Just used a small floor jack but you do have to pry up the battery/ABS tray quite forcefully to get the first/last inch or thereabouts.
