My clutch is slipping, need help....

[bhwilder]

The reason I believe my clutch is slipping is I can hold the spur gear and give it light gas and the tmaxx doesn't move that much but the clutchbell really spins fast and it's almost as if you can feel the clutch spinning, know what I mean?
Don't get me wrong, when I start it and run it, it gets up and goes pretty good, it just seems that it should have more power than it does and from reading all the posts about the Sirio's, it should.
I read on another thread that's how you can tell if your clutch is engaging good enough and that would explain why it doesn't have the power it should.
Most guys with the Sirio .18 say they can willie on command and have tremendous power although mine doesn't.
Now before everyone says it's not tuned correctly, believe it is pretty darn close so please, for arguments sake, let's just say that it is the clutch slipping.
So how would you fix it to where it doesn't slip???
I currently have a 3 piece aluminum clutch and a 20t clutchbell.
I have also had the Mip clutch. It done the same too.
Sirio tx .18
big bore pipe
1 1/2 gallons through it
McCoy #9 plug
Trinity Horsepower fuel
Foc
:\

 

[SkyMaxx]

Based on what you are saying it might be the clutch...but it could be something entirely different.

1. You said that you were able to hold the spur gear with the clutch bell spinning really fast. Holding the spur gear stationary will not allow the truck to move at all. If you are doing this and the clutch bell is still able to spin very fast, then the mesh is not set. With power on the engine and adding throttle you should not be able to grab the spur gear if the mesh is set properly.

2. The above is most llkely the problem. Why? Because if the clutch shoes were slipping, you would be able to hold the spur gear...it would lock down the clutch bell....and you wouldn't see the clutch bell move at all....HOWEVER, the engine would rev, the clutch bell would get really hot from the shoes moving around the inside of the bell, etc, etc.

So, I would suggest checking to see if your mesh between clutch bell and spur gear is set properly. In the case that you need to know how to set the mesh, read below:

Originally posted by SkyMaxx
Setting gear mesh is very important to the longevity of both gears and the components driving and being driven by the gears.

Here's how to do the mesh check.
1. Loosen the screws that hold the motor mounts to the chassis plate (don't take them all the way out).

2. Make sure you have both spur gear and clutch gear on properly (since you've mounted the spur and the clutch is attached to the motor, you probably have little to worry about here).

3. Take the plastic bag that the spur gear came in (a ziploc bag will work just as well) and place one thickness of the plastic between the two gears.

4. Push the motor back into place so that the two gear compress on the plastic.

5. Tighten the motor mount screws (making sure that the motor mounts are as square to the chassis as possible...you want the gears to have as even a surface to surface contact as possible).

6. Pull the bag out. The gears should rotate freely and mesh together just right.

Hope this helps...

 

[bhwilder]

I wouldn't advise anyone to grab the spur gear under throttle! So let me make that clear.
After you start the tmaxx and It's at idle speed, hold the spur gear pretty tight.....
but anyway the mesh is pretty close to perfect, I already do the paper trick to check the mesh.
thanks, but it''s defenitely not the mesh.

 

[olds97_lss]

Maybe your clutch spring is to stiff? Or, you have the wrong flywheel/shoes/clutchbell combo?

It's hard to say. I run the MIP 2 shoe on my 21 maxx and the same on my wasp 18 sport maxx. Both hook up really well. I tried al integy shoes on my 21 maxx and they just melted and destroyed the spring. I stick with the composite shoes now.

 

[bhwilder]

olds97_lss
Never thought of that one...
But do you think that could be the same with the MIP clutch (2 piece) also????

 

[olds97_lss]

Don't know. Depends on how you hooked it up. Although, I've used both sets of holes on the MIP and both hook up fine.

Did you think maybe your flywheel is slipping and not the clutch? If your flywheel is slipping it will appear to look like your clutch is.

 

[bhwilder]

Slipping Clutch...

I'm using the springs that came with the clutch.
It came with the flywheel, clutchshoes and 2 springs,
all aluminum....

I'd say it's possible, but I don't know, probably not in this case,
I really had to hulk the flywheel nut down to get it to fit correctly, so it's really tight on the shaft, so I wouldn't think that, but it is possible I suppose....
As I get different answers, I check it out to see if that could be the problem, so I'll check that again...
Any other clues???

 

[olds97_lss]

I really don't know anything else that could help. All I can think of is the flywheel thing. You may have the nut tight, but that doesn't necessarily mean that the fit is tight between the flywheel and collet. You may be bottoming out on the crank shaft threads with the nut and be thinking it's tight. I have done the same.

Did you put shims behind your flywheel to hold it where you wanted it or are you just depending on the collet biting down?

 

[bhwilder]

just depending on the collet...
I'll check that out.

I took a good look at the inside of the clutchbell and can see where the clutch is definetly slipping... There's rings around the inside of the clutchbell and they have made grooves in the clutchbell, so it does definetly slip!!!
Now to prevent it????....
Even lightly sanded the inside of the clutchbell a long time ago and that didn't help...

 

[olds97_lss]

When running al shoes, you wear out cb's a lot faster. You may want to change to composit 3 shoe if you want the grip. I thought GA made one, but theirs is al as well.

Found a composite 4 shoe that's relatively cheap: RadRC 4 Shoe

 

[bhwilder]

I'm headed for new clutchbell and shoes anyway, tried the stock 2.5 shoes, the Mip shoes and now the 3 piece al, looks like the Radrc 4 shoe is next...

 

[SkyMaxx]

Originally posted by bhwilder
I wouldn't advise anyone to grab the spur gear under throttle! So let me make that clear.
After you start the tmaxx and It's at idle speed, hold the spur gear pretty tight.....
but anyway the mesh is pretty close to perfect, I already do the paper trick to check the mesh.
thanks, but it''s defenitely not the mesh.

I wasn't suggesting you to grab the spur under throttle. I was interpretting what you wrote in your original post. You implied that you were doing so.

Regardless, if the shoes are slipping around the clutch bell there will be a build up of heat and the bell will get pretty darn hot. That would be a real good indicator.

As you have already broken the clutch down and noted grooves on the inside of the bell, that is another indicator.

I'm going to concur with Olds on his suggestions.