Need some advice.

[easy rider]

I got a question. I bought an off road 1/8 clutch kit and 17 tooth clutch bell. The clutch kit came with three sets of weighted springs. I think it’s called VR pro clutch system.


Anyways, my issue is no matter how I shim it, when I snug up the crank bolt, it binds. Like I said, I’ve shimmed it with one. I’ve shimmed it with 4. It doesn’t need any shims. But, if I don’t put at least one it it, the clutch bell compresses so hard the clutch shoes get hung up in the clutch bell.

I’ve never had this problem. I tried a different clutch bell and it does the same thing. So, it’s not a faulty bell. I truly don’t know what to do at this point.

Should I prep the bell? I understand the roughing it up but, it seems these clutch pads are big as is. Also, is this normal? I don’t have much experience in nitros besides Traxxas. Needless to say this has never happened with the Traxxas monster trucks I’ve had.

I’ve ordered a new system but, I’d dang sure like to make this one work too. Thanks ahead of time and any and all advice is welcome.

 

[D3MON]

pictures would help alot, but it sounds like you need a shim kit that extends the crankshaft. again please post up some pictures to confirm, but it sounds like the crankbolt is tightening against the clutchbell bearings before its tight to the crankshaft so its clamping down on the bearing causing the binding.
something like this:
https://www.amainhobbies.com/protek-rc-1-8-scale-flywheel-nut-collet-shim-kit-ptk-7150/p222026
the metal sleeve "extends" the crankshaft so the screw tightens against that before the clutchbell and bearings.

 

[fstnd]

Sometimes the bearings in a clutchbell can go in one way and out the other way, so there isn't anything holding them other then clearance. When that's the case I just use a wider shim than the bearing

 

[ohsnap]

pictures would help alot.

Anyways, my issue is no matter how I shim it, when I snug up the crank bolt, it binds. Like I said, I’ve shimmed it with one. I’ve shimmed it with 4. It doesn’t need any shims. But, if I don’t put at least one it it, the clutch bell compresses so hard the clutch shoes get hung up in the clutch bell.

Definitely pictures.

I can't wrap my head around:
" It doesn’t need any shims"
" I’ve shimmed it with one. I’ve shimmed it with 4."

If it doesn't need any shims, then how can you get 4 in there and where are you placing them?
Are they under the clutch bell, on top of the clutch bell - both?

In my eyes, an ideal arrangement would look something like one shim on top of the clutch nut and supporting the clutch bell bearings and no additional shims needed because the top bearing was flush with the end of the crankshaft when I test fit the whole enchilada.
(or just so short of the end of the crank so that I could not or would not need to fit another shim on top)

Add shims if there's a gap between the outer bearing and the end of the crankshaft...

That bearing supporting shim (or shims if necessary) act as the buffer that keeps the clutch bell and bearing elevated above and not compressing the clutch shoes.

Stacking more shims than needed on top of the clutch bell and exceeding the end of the crankshaft results in binding issues.
Not having a sufficient gap between the underside of the clutch bell and the top of the clutch shoes results in binding issues.

I have at times needed to make a shim that I have on hand thinner.
A flat surface, 300 grit waterproof sandpaper, and a figure 8 motion with the shim getting pressed by the tip of the finger does the trick.

Find your Nirvana...

 

[ohsnap]

Did you check out the Clutch Installation and Rebuild thread?

Thread 'Clutch installation and rebuild'

Mar 23, 2008

RC Clutches 101

These stickies are to serve as reference pics for any clutch related problems. Just to keep the thread clean for any additional information, please post questions in the appropriate forums. Additional photos, info and advise will be posted in this thread as needed.

Savage 3 shoe clutch assembly:

A defective clutch can cause starting problems. The engine will start and run when you hold the car up, but it stalls when you apply the brakes or when you put it on the ground. Fortunately, you can quickly diagnose a faulty clutch...

• Rolex
• Replies: 1
• Forum: Nitro RC

• 

It has what looks to be an HPI Savage illustration, it might help you.

 

[easy rider]

I’ll get some pics or video up this evening.


Without shims anywhere, the clutch bell is flush with the crank. With 1 shim over the flywheel nut, it’s slightly longer. So, I put a shim between the spacer and outside bearing. But, it binds when I tighten it. Just like with only 1 shim over the flywheel nut.


So, I’ve added two shim over the flywheel nut. I then have to add two between the spacer and the outside bearing. Etc….


It gets better as I add more shims but, by this time I’ve exposed the back of each clutch pad, from the back side of the bell. Etc…. But, when I snug it up like it should be it’s binding shimmed like this as well.

 

[easy rider]

I want to thank you all. I figured it out. The spacer that goes between the crank and crank bolt came stock with this hobao .30. They run a bigger bearing in their clutch bells then standard bearing. So, the spacer was bigger than standard. When I was tightening everything down the spacer was getting into the bearings. You guys prompts is how I figured it out. Man, I was stumped last night.


Thank you all for the help.