Please Help: Driven Unit Trouble

[Johnnyboy]

Hey guys,
This is actually my first thread here, but I'm hoping that you'll be able to help me with an issue I'm facing with my Manco Rattler LXT. I bought it about two weeks ago, and it's only been working for about three or for days. Recently, the driven unit destroyed itself.

As you can see, the cam buttons are completely gone, and the spring was toasted so I pulled that out as well. I successfully removed the retaining ring in front of the cam to replace the spring, but I have absolutely no Idea how to get that thing off! It is part of a Comet Series 30 torque converter, and I don't believe it's ever been removed. Can someone please tell me how the cam can be taken off?
Thank you in advance,
Johnnyboy

 

[Hambone]

You can get cam buttons and a new spring on ebay for somewhere around $20.

It took me about 2 hours to get my driven apart, it's a REALLY tight fit. I used a rubber mallet and lots of wd 40. Don't be afraid to beat on it a little.

Good luck!

EDIT: pull it off the jackshaft before you try to take it apart.

 

[Johnnyboy]

You can get cam buttons and a new spring on ebay for somewhere around $20.

It took me about 2 hours to get my driven apart, it's a REALLY tight fit. I used a rubber mallet and lots of wd 40. Don't be afraid to beat on it a little.

Good luck!

EDIT: pull it off the jackshaft before you try to take it apart.

So I don't have to unscrew anything, only slip it off?

 

[Hambone]

So I don't have to unscrew anything, only slip it off?

After you take that clip off the end, it should just slide off.. with a little force

 

[Johnnyboy]

After you take that clip off the end, it should just slide off.. with a little force

Thanks Hambone! I really appreciate the help!

 

[Johnnyboy]

just went at it for half an hour or so. I must've emtied enough wd40 to make the thing toxic, but it still didn't move an inch. Then again it was really hard to get a good angle at the cam with the sheave right behind it. However, I'm still confused. How could the retaining ring have secured the cam? it didn't block the keyway or the shaft the cam is mounted on.

p.s. do I have to slide of the whole driven unit to get off the cam?

 

[qtband]

Here's what I have done.
Take the secondary off the kart and lay it on a slightly opened vise without the jack shaft. Place a shoulder bolt (like the pic attached) where the jack shaft was. You have to make sure the shoulder of the bolt is not larger than the squared part of the center shaft of the secondary. Then start tapping the shoulder bolt which will drive the center shaft out. I say tap, but I usually end up smacking it pretty good. When you get near the end and it's about to pop off, be prepared. The secondary has been preloaded and will spring on you. Not bad, but be ready.
When you do get it off, it can be difficult to put back together. I usually have to clean up any burrs and scratches on the shaft in order to get it back on. I've used sandpaper, file, 3M pad, anything to clean it up. Test the fit without the spring. When it goes on good, put the spring on, preload it and attach the c-clip.

 

[Johnnyboy]

Here's what I have done.
Take the secondary off the kart and lay it on a slightly opened vise without the jack shaft. Place a shoulder bolt (like the pic attached) where the jack shaft was. You have to make sure the shoulder of the bolt is not larger than the squared part of the center shaft of the secondary. Then start tapping the shoulder bolt which will drive the center shaft out. I say tap, but I usually end up smacking it pretty good. When you get near the end and it's about to pop off, be prepared. The secondary has been preloaded and will spring on you. Not bad, but be ready.
When you do get it off, it can be difficult to put back together. I usually have to clean up any burrs and scratches on the shaft in order to get it back on. I've used sandpaper, file, 3M pad, anything to clean it up. Test the fit without the spring. When it goes on good, put the spring on, preload it and attach the c-clip.

Thanks, man! I'll give it a try. Any idea how I could take of the unit, though?

 

[qtband]

Once you take off the secondary, the jack shaft sometimes is hard to get off, too. You can put it on the vise (as described above) and use a center punch or flat round chisel and punch out the threaded shaft. Then continue as stated above.
Let us know how it goes...

 

[Johnnyboy]

Once you take off the secondary, the jack shaft sometimes is hard to get off, too. You can put it on the vise (as described above) and use a center punch or flat round chisel and punch out the threaded shaft. Then continue as stated above.
Let us know how it goes...

Thank you so much, but how would I get the secondary itself off (ie. the cam and sheave.)?

 

[qtband]

You should have a nut on the other side of the jack shaft. You have the front side off, take the back nut off. Also, remove the chain and belt. You can then just slide the shaft out with the secondary.

 

[Johnnyboy]

You should have a nut on the other side of the jack shaft. You have the front side off, take the back nut off. Also, remove the chain and belt. You can then just slide the shaft out with the secondary.

You are the best! I'll see how it goes as soon as the other pats arrive.

 

[Johnnyboy]

Can you guys help me with one more thing, though? I understand that the keyway keeps the unit from spinning around on the shaft, but what keeps it from sliding off (left to right)?

 

[landuse]

Can you guys help me with one more thing, though? I understand that the keyway keeps the unit from spinning around on the shaft, but what keeps it from sliding off (left to right)?

You would have a bolt holding it on or have a setscrew

 

[Johnnyboy]

You would have a bolt holding it on or have a setscrew

In the last photo, no such bolt is present. Could I just slap a nut on that end?

 

[KartFab]

he meant nut. Its probably a 5/8" fine thread nut. get a NYLOCK nut if at all possible. If not, use blue threadlocker to hold it on. Do NOT overtighten the nut as it will cause pre-mature wear on your jackshaft bearings. The only reason a nut is used is to keep the driven from sliding back and forth, not to holt it 'tight' against anything. This is very important.

 

[landuse]

In the last photo, no such bolt is present. Could I just slap a nut on that end?

he meant nut.

Sorry, I meant nut. I feel as if I am going nuts....