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Old 09-08-2006, 12:06 AM   #16
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I used to chew them all the time with the stock Mugen clutch, but since I went to the Werks clutch, I have almost 2 gallons on the set I have in there now...still fine. I think it's the heat that kills them. I was changing them every 6-10 tanks and they were blown out...now they live forever.
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Old 09-08-2006, 06:22 AM   #17
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We've been thinking at this point that it was engine bearings creating crankshaft slop, but my 528 is like brand new and it does the same thing. Is there a way I can try and reduce the heat? I thought about trying a vented bell. Right now I'm running stock Mugen bells. The last set I exploded moved the bell forward and it took out itself and the spur gear. Chewed them both on 45 angles.The shimming sounds about right. We've tried that a couple of different ways with no real differences. Mugen instructions call for shims that are 5x10x1 to contact the bearings but that would contact the inner race and outer instead of just the inner. Wouldn't think that would be right???
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Old 09-08-2006, 07:46 AM   #18
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Shims must contact inner race only.
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Old 09-08-2006, 08:03 AM   #19
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Although heat is not good for our bearings it is not really the problem. The problem is when the bell heats up it expands and if the bell is not shimed properly it will put the bearings in a bind. This along with the heat is what causes them to blow. You can sometimes reduce heat by using a softer spring. A softer spring will cause the shoes to not slip as much and will gererate less heat.
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Old 09-08-2006, 08:05 AM   #20
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So we are correct on that with the shimming also. Looking at my 528 clutch that I ran yesterday three tanks before smoking it seems as though it could be a heat issue. Is there any way of reducing heat? When I tried extra hard shoes from mugen or ofna they just melted and twisted. That is why I went to the Fiorni. No problems with the clutch itself anymore, just bearings.
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Old 09-08-2006, 08:06 AM   #21
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so possibly try removing one of the three springs on the slider and try that for less heat?
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Old 09-08-2006, 08:53 AM   #22
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"That is why I went to the Fiorni. No problems with the clutch itself anymore, just bearings."

IMO if you are toasting bearings using the Fiorni slider or the Werks clutch you either have very poor bearings or you are not leaving enough end play.

With a three shoe setup if one of the springs is weaker or the springs don't have the same tension any longer it will cause one or two of the shoes to contact the bell before the others and again will put the bearings in a bind. This does not happen as much in the slider and the Werks clutch because of the springs they use. The shoes in those clutches will most always hit the bell at about the same time causing less slippage and less binding which will prolong bearing life.

If you are melting shoes in the other three shoe setups you are using a spring that is too stiff for where you are driving which is causing a lot of slipping and with that a lot of heat.

What kinda bearings are you using? I only use Avid bearings and IMO they are about the best for what we use them for.

Here is a link..........Avid Bearings
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Old 09-08-2006, 08:55 AM   #23
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Quote:
Originally Posted by mugenchad
so possibly try removing one of the three springs on the slider and try that for less heat?
Actually less slippage which in turn will cause less heat.
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Old 09-08-2006, 09:55 AM   #24
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yeah thanks that is something I haven't tried yet. Does anyone know anything about softer springs or stiffer for Fioronis??? What about the turbo slider 4 shoe. At this point I'm up to trying things that I haven't yet. It's pretty crappy at this point. Almost ready to sell out and buy a bass boat Anyone know about a good vented clutch bell similar in width and size to a stock mugen???

thanks everyone you're heading me in the right direction
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Old 09-08-2006, 09:58 AM   #25
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Are you blowing out some of the grease from the clutch bearings before you install them in the clutch bell? As the clutch spins and heats up it will spit out some of the grease and may be getting on the clutch shoes causig them to slip which in turn could be the cause bearing to blow out due to heat.
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Old 09-08-2006, 10:01 AM   #26
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No, I clean the bearings first with motor spray. I have tried one drop of bearing oil and I have also tried with no oil because I thought it might cause slippage, like you said.
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Old 09-08-2006, 11:03 AM   #27
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mugenchad:

In my experience with clutch bearings most failures happen because of improper shimming or alignment. I can regularly get 2-3 gallons on my clutch bell bearings. Clean them first as you say you do. I run a Jammin CRT Pro completely stock. I run the Jammin Aluminum silver shoes with 1.1 gold springs. I shim my clutch bell to have about 1mm of side to side play. This keeps the heat factor low with aluminum shoes. After I set the CB properly on the engine I spin the CB and rotate the engine in my hand with the CB facing in all 4 directions possible. The CB should spin freely in any direction but a tad less only when the CB is facing straight up. This is because of centrifical force of the weight of the CB falling down. Make sure the CB teeth and spur gear mesh in the center of the teeth and not tight but with some play. The alignment is critical to take stress off the bearings. If possible get a 1 piece engine mount and set it properly. This will do 2 things. Strengthen so no flex can happen and assure proper alignment.

I just finished racing at a Canadian Nats in Canada won the 20 minute B main, bumped and came 2nd in the 45 minute A main with no time for clutch maintanence. That is 1 hr and 15 minutes including 5 minute warmups in racing conditions. I checked my clutch and bearings after and they are still in great shape. In fact, my clutch shoes, springs and bearings have about 11 - 5 minute heats, 1 - 20 minute B main, and 4 - 45 minute A mains on them. The whole clutch setup is still in great shape!

Please don't take this wrong, but I really doubt your bearings are imploding other than the above reasons. With this happening with 2 different engines that leads me to not believe that it is an engine problem at all. Also make sure that your chassis is/has been drilled properly for engine mounting. If it hasen't, there is your problem.

Goodluck....
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Old 09-08-2006, 11:14 AM   #28
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What kind of bearings do you run?? At this point we haven't overlooked checking any of the things that you have said. How tight are you setting your meshes? And what is the best way to be perfectly lined up? I'm running Mugen Prospecs with milled out underside for motor mounting. Once I think I've found a good mesh I pull the motor to do clutch maintainence, leaving the mount in the car. At this point I'm thinking of trying a vented clutchbell, seems like some of the guys are running them.

Thanks for your help, congradulations on your run last weekend
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Old 09-08-2006, 12:25 PM   #29
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mugenchad:

Thanks for the congrats!

As to setting mesh I lean to the little bit tighter mesh than a sloppy one. I've got friends that set a bit looser than me but I've not had any problems. I find that being on the loose side with the mesh makes the drive train a bit louder and I'm sure it causes more wear and tear (I haven't been able to prove it, but I believe that). I try my best to use something with a 90* edge like a clear plastic protractor when I align my engine so that it looks like its aligned properly looking from the top. When I believe everything is aligned I then tighten the engine bolts to almost tight but some slippage allowed. I then put my finger on the CB and rotate the spur gear to make sure that I have the same play/mesh thru out a full spur gear rotation. This sometimes cannot be perfect because either the spur or CB could be a bit out of round. Just make sure everything is close and go from there. Then I suck the engine bolts down tight and recheck the spur/CB to make sure nothing has changed or binding.

As to bearings I use rubber shielded from my LHS. I do want to try some Avid bearings tho. Can't go wrong for a $1.00 apiece.

I just re-read my first comment and I meant to say to check the alignment holes that are drilled in the chassis that they are straight. If not, even the engine mounts will be out of line. If possible try to find another Prospec chassis to lay on top of yours and check to see they (holes) are the same. Things can happen to make your chassis out of line just a bit but not really noticable, even from the factory.

I can also tell you that I race on rough tracks with big air jumps. I've been told that I need the Z brace for my truggy but like I say its stock and I've had no problems with chassis flex. And I've had some really bad cartwheel landings or landed completely upside down first after 35' of air after attempting a quad about 30' in length.
I shuddered everytime but was able to drive away as nothing happened. Obviously, that is a testament to the Jammin CRT Pro but I sure don't like that happening. But that has proven to me at least that if the chassis is braced well the cars are tough. I have no doubt that the Mugen vehicles, especially the Prospecs are tough as hell as much as my Jammin is. So that takes the flex problem out of the equation.

I have used the vented bells and I really like them. You can check your shoes without taking the CB off because of good visibility to the shoes to see if they need any maintanence. The Vented CB's also help to disipate heat to because of the less rotating mass.

Try these ideas out, I'm sure you'll find the problem.

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Old 09-09-2006, 08:27 AM   #30
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Thanks again for your advice. Its just getting frustrating at this point not so much expensive. You know $1500 to $2000 invested in each of two vehicles, plus a lot of time and homework and go traveling to a big race and lose a main because of $2 worth of bearings? I've been dealing with this all season and no one has given me any off the wall ideas. I'm going to try and use a straight edge from now on to set my initial mesh.

Thanks for your help everyone, it is much appreciated...
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