As promised, detailed clutch upgrade process.
Before I get started, this won't work on the latest clutches from Taiwan. Let me repeat....this process won't work on the latest clutches from Taiwan. This upgrade will work on clutches sold by Whizzer USA, and automatic clutches on new edition Whizzers except the 2001 Pacemaker II. This upgrade is for the automatic clutch only, not the CVT drives used on the Ambassador II [will work on Ambassador I] and NE-r models.
First & foremost the "heart" of the system is the one-way needle bearing, as the clutch uses this bearing for two purposes. One, to allow the rear wheel to turn the motor to start [pedal start], and secondly to support the clutch prior to full engagement. Once the clutch goes into complete lock it depends on the two small 6901Z bearings riding on the 12 MM mounting bolt.
Problem is: Every machinist, engineer, and anyone that knows anything about needle bearings knows they must ride on a HARDENED sleeve, guess Taiwan didn't get the memo!
During the process of upgrading a clutch for a customer I was able to take pictures for this post, and it is evident the original sleeve was grooved and needed replaced. It is also evident the original sleeve was soft, very soft, as the tool bit cut it off like a "hot knife through butter".
Having rebuilt hundreds of these clutches, only once did I see a hard sleeve, and it was hard in the middle and soft on both ends. Therefore it was no surprise how quickly the sleeve can be removed in a lathe. Once the original sleeve is removed, the surface must be cut down to allow a metric sleeve to be pressed on. I won't discuss the final size, as your machine shop should determine the press fit clearance. I don't want to be responsible if the machine shop breaks the clutch by using my numbers. The sleeve I.D. is 25 MM, so have the shop deduct whatever they think is a correct press fit and go for it. I broke two hubs in 2005 using incorrect press fit numbers, so best left to the experts doing the work.
Next the INA bearing sleeve has to be re-sized, as it is too long. BTW, you won't cut that sleeve with a tool bit. It must be ground to size. After arriving at the correct size, I apply Sleeve Retainer liquid on the inside and press the sleeve in place with a 12-ton press.
Many small bearings are destroyed by simply tightening the clutch mounting bolt to the arm. If tightened too tight the bolt crushes the centers inward and damages the bearings. A simple solution is to place a spacer between the two bearings to stop the bolt from pushing the centers inward. Now back to Taiwan.instead of accepting a solution they found it necessary to alter the design and it didn't work. Why you asked? Because they used some low grade conduit instead a real spacer, and as the bolt tightened, the spacer simply crushed and then the bearings were next. You will see in the pictures I make a steel spacer to make it impossible to trash the bearings during installation. A few minutes on the lathe and presto a real spacer, wonder how hard it would have been to make it correct the first time. Taiwan fought the idea of a good spacer to the point of installing 5 [that's right 5] bearings to stop them from crushing during installation. They had 3 together on one side and 2 on the other end, and guess what it didn't work as I often have to replace bearings in those clutches. The units with 5 bearings are most commonly the 70 MM version with all the little holes in the hub.
A close look will show where the small washer cut into the drive side of the clutch, I simply took a very large fender washer, drilled a 15.32" hole and pressed it onto the 12 MM shoulder bolt [don't be surprised if the washer doesn't need to be pressed on as 12 MM bolt isn't likely to actually be the shoulder size]. The washer needs to be "snug" on the bolt as it works better if stationary, and add a very small amount of grease on the inside.
Hopefully these photos will supply the information needed for the DIY group, and good luck. If done correctly the clutch will work well and last a long time. One of the clutches I upgraded in 2006 has over 20,000 miles on it and works like new, therefore it is worth the effort.
I normally paint the clutches low gloss black, however this one came in a light color scheme, so I painted it white to better match the front side.
I was charging about $110.00 to completely upgrade the clutch [more to do on the other side of some clutches], however after a few concluded I might be making money, I found I wasn't. Guess I need to raise my prices so they can be correct. Just joking, as I don't provide this service to make money.
As far as I know I am the only person crazy enough to spend hours making these clutches work, and would welcome someone else helping out. I always have a long waiting list for clutch upgrades, and always have plenty of work, so just think you can work about 4 to 5 hours on each clutch for almost nothing [less than $20.00].
If anyone has any questions please ask.
Have fun,
