cetme308

On my second tank of my new Savage X RTR, I noticed these black bits/shavings right under the clutch bell. The spur gear had no damage. I called HPI support and he said it sounded like the shoes were on backwards and was going to send me replacements. I took off the engine and blah blah. The clutch bell was full of the stuff and I do see wear on the shoes but is it melted or is it on backwards? I thought if it was on backwards then the clutch bell wouldn't rotate at all and I was having no issues with those wheels spinning. I can't find any dang info if the W is supposed to be against the flywheel or not. Anyway, I attached pictures so please look at them and tell me whats going on.

1QwkSport2.5r

They look like plastic clutch shoes to me. If they are, the little bits in the clutchbell are little melted globules of clutch shoe. The answer is to replace the plastic shoes with aluminum shoes.

cetme308

Yeah they are plastic but why are they melting? Is there something that needs to be tighten/tighten or adjusted?

Anthoop

Looks to me as though there has been a lot of slipping...possibly caused by oil.
I would just give them and the clutch bell a good clean up and try again....as said those plastic shoes do not last all that long...there are many different types of shoes available when the time comes to replace.

Rafael23cc

My Feedback: (6)

Take a close look at your assembly. If you look close at pics 3 and 6 there is a noticeable step on the clutch shoe closest to the flywheel. That means that the clutch is not being inserted fully into the clutch bell.

Rafael

nitroexpress

If you look at the first picture. Looks to be oil slinging out of the bearing or possibly an oil substance which was sprayed on or near the bearing. Looks like oil contamination of the shoes caused them to slip.

cetme308

Thanks for the response guys. Yeah I seen that 'step', does slippage cause that? I cleaned the bell and make sure it was totally dry. I didn't take the shoes off as I don't have my tool yet. I cleaned them the best I could and then put everything back together. Now, I'm still in the breaking-in phase, could I be running too rich and its causing fuel/oil to go places it won't when I lean it out?

RcNitroNerd

The only oils you should have coming out should be out the exhaust. That happens when you run really rich. if you have a clutch that is made out of plastic, that takes a lot of heat and rubs a lot, your going to have some kind of wear. The aluminum hop up lasts way longer, and can with stand more.

cetme308

So will the plastic shoes rub pretty much all the time and I'll be seeing some bits after reach run? I mean if thats normal then yeah, I'll upgrade to the aluminum.

cbaker65

I think its kinda weird,Ive ran the same shoes hard on Mgt for 3 yrs,even though they are of a plastic compound,they
are alot more durable then what people think.
1 or 2 things could be happening.
There was a subtance that got on them causing massive slippage like what was mention.
Or the idle is set to high on the engine causing the shoes to be half engage were they are dragging
all the time.
Those shoes still have plenty of life left on them,when the spring starts making contact with the
bell,then you should replace them.
Try checking the idle on your engine,you dont want it idleing so too high,an check an make sure
that the bearing seal is not leaking on the engine...

cetme308

When you say the idle is set too high, that would cause the truck to want to move when it should be stationary correct?

Bearing seal, is that the one which the flywheel would be right up next to?

cbaker65

Yea,on the idle,you dont want the truck trying to keep creeping forward,you want it to sit still on idling,also,
its really not good to putt the truck around.
An on the bearing,yes,behind the flywheel,but then,the flywheel sheilds the clutches,so that maynot be
the case.
As far as the shoes coming out of the bell alittle,that maybe just a shim problem,which the bell may need a shim
in the front where the screw or clip holds the bell on.
It might be a good idea to fine tune your linkage too.You dont want the brake engaged when you let off the
throttle,make sure with your radio on that your truck rolls freely with out restrictions.This would help save the
wear & tear on your clutch an other parts....

cbaker65

Oh,I also noticed that it only has 2 tanks of fuel ran through it,so there should be Q's on how you broke
the engine in.Holding the truck still on the ground,or did you have the truck suspended with the wheels
off the ground?
If you held the truck still on the ground,then that will fry the clutch shoes real quick,an you shouldnt
hold the truck still when its trying to move,or if you are revving it up...

cetme308

A shim you say, I'll make a note of that. I didn't notice any issues with the brakes besides being pretty soft but I'll do that test tomorrow. Thanks for the info.

cetme308

The first tank it was up on blocks and the second tank I was doing slow circles.

cbaker65

Yea,no problem..
Nitro rc's arent really ready to run out of the box,they require tuning an adjustments,like the throttle & brake linkage,
an even the transmitter has servo tuning adjustments.
But always make sure that you can hand push the truck,the truck should move freely with out no restrictions or
an binding.

proptop

My Feedback: (8)

This is what it looks like to me too...
The bearings in the clutch bell have a light grease in them...and sometimes, when the clutch gets hot, the grease oozes out and slings around in the clutch assembly, causing slippage.

There shouldn't be much grease left in those clutch bearings anymore, so chances are your slippage will be over...but you should kep tabs on your clutch bearings...w/o grease, they will wear quicker.

cetme308

Thanks for the info. Will the bearings start to squeak if they are getting too dry?

proptop

My Feedback: (8)

They might...I've never heard that...probably because there's so much other, exhaust and mechanical noise drowning them out?

Just go by feel...you will develop a feel for these things over time, if you haven't already...
When the bearings get to the point where you need to replace them, clutch bell starts to get a little bit wobbly...and the bearings will usually start to feel rough / grunchy...

By the time your clutch shoes need replacing, so will the bearings...it's common to replace them all at the same time.

cetme308

I'll make a note about that, thanks for the info.

1QwkSport2.5r

Grunchy... Now there's a new word for my vocabulary! LoL!

proptop

My Feedback: (8)

Ah yes...that's the, um, "technical" term...


Kinda sounds like the name of a granola bar though, huh?

1QwkSport2.5r

Haha! Indeed it does.. Kinda like a "snarky" or "squishy" carb prime. When the carb sounds "squishy" it's ready to fire. My buddy favors "snarky".

Anthoop

I just thought it was misspelt...graunch... http://www.oxforddictionaries.com/de...nglish/graunch

Also not sure if you guys have crunchie bars over there... https://www.cadbury.co.uk/products/Crunchie-2389?p=2389

proptop

My Feedback: (8)

Hi Ant...maybe that's the way you pronounce it when using "the King's English"?
Over here in the Colonies we ain't got no accent (except fer thoze down in Lawn Guyland)

Another thread has a question about Teflon shielded bearings, and IIRC that was a recommendation from some of the guys who raced on the Off Road track behind CRC Raceway, to use Teflon shielded Clutch bearings because they resisted the heat better. (Calandra Racing Concepts is based here in Rome, they are fairly well know for their 1/12 scale Carpet Knife series of cars, among other things)

Another thing that comes to mind is the use of just one or maybe two Aluminum clutch shoes, to tune the grab of the clutch.

I used to do a lot of Mr. Fixit work for a couple of local hobby shops, but don't have the time anymore, but something I often found useful was the advice I'd get from some of the racers.

I recall swapping the clutch shoes in a Savage over to Aluminum, and the first time I nailed the throttle, the clutch hit so hard that it did a back flip...