I have a 300/4.9 new engine. I had the flywheel balanced zero balance, as the 4.9 uses, and had the clutch balanced with the flywheel.

Now I'm replacing the clutch. Do I have to have the flywheel checked for balance?

 

I don't think the clutch and pressure plate figure into the engine balancing equation - as long as they are perfectly centered on the flywheel. And if the clutch set is balanced with the flywheel, the pressure plate needs to be marked so it can be installed in the same orientation, much like you should do with a driveshaft and its yokes, and the yokes which the driveshaft yokes bolt up to.

You could have the flywheel balance checked by someone other than who balanced it, but if the truck/engine wasn't vibrating, I wouldn't worry about it. You were experiencing a noise with the old clutch as I remember?

 

Normally the flywheel is zero balanced by your machine shop and the clutch comes zero balanced.

If it truly was balanced as a unit, which no competent shop would do, then your best bet would be to get the flywheel balanced and then install your new clutch.

 

Chalk another one up to my inexperience. The flywheel was balanced with the clutch, and I was given a mark on both to line up on installation. A noise caused by imbalance would get worse with rpm's, right? The noise I experience vanishes as the rpm's increase. I had the noise before the trans got rebuilt and after. The clutch stayed, so I am wanting to eliminate it as a source of the noise by replacing it. Does that sound reasonable? Thanks.

 

have you tried running the engine with the trans removed?

 

Oh, no, don't suggest that. The implications scare me. Trying to think it through. What on an engine would make a growling sound, and disappear when the clutch is engaged? The engine doesn't stop when the clutch is pressed, but the trans is disconnected from the driveline, from power, as is the clutch. It doesn't make sense to me that a noise in the engine would disappear with rpm's. And, since the trans worked fine on the shop drive simulation machine, then, it stands to reason that the noise must be coming from the clutch. Or?

 

Normally a clutch doesn't make any noise especially when it's engaged . are you sure your throw out bearing isn't bumping ? even slightly could cause a noise.

Chances are you can replace the clutch anyway without rebalancing the flywheel. probably they zero balanced the flywheel then just put the clutch on and marked it. I can't imagine them doing it as a unit. of course there 's no way to know this for sure it's just a logical assumption.

 

Hey there. The throw out bearing on the zf is a slave cylinder and the t.o. bearing rides on top of that and is always in contact with the prongs of the p.plate. My first reaction was that that was where the noise was coming from, but I can't tell anything with it together. There is some confusion at Summit with this Ram clutch as to whether it is for a 5.0 and a 5.8 only. So I've purchased a new clutch and will soon be installing a new p.shaft bearing, and slave/t.o.bearing combo. I noticed on RockAuto that there are two diameter t.o. bearings, so I want to eliminate guess work and get the two that are made to be together.

I didn't know that SACHS and ZF were the same company. But, it says so right on the box. Thanks.
Another member mentioned that I should try to start the engine w/o the trans on it. Since it was a new engine, I think I will try that just to eliminate another possible source of the noise.

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It's funny you mention that about the shop just putting the balance mark to line up clutch with flywheel, and not actually balancing them together. That's what I thought when I learned that one clutch can fit multiple engines with internally/external balancing. The only way could do that is to have the clutch zero balanced. Anyway, I'm sure it's not the first time I got charged for work that never got done.

 

The clutch should be zero balanced out of the box, so probably all they did was balance the flywheel. therefore you should be good to go. this would be the normal routine anyway.

I'm not familiar with the throw out bearing style you're talking about but it sounds like a good place to get noises and extra wear.

 

I would think that there actually are things in the engine that can make noise, then stop when the clutch is depressed. I don't know just exactly what those might be, but my point is based on the fact that when the clutch pedal is depressed the pressure exerted forward on the flywheel will tend to push the crank forward into contact with the thrust washers/bearings/surfaces inside the crankcase.

Again, what that might do to any possible noises coming from the engine I have no idea. I just wanted to mention that this relationship does change with the movement of the clutch.
A shop truck we had lost it's thrust washer (Toyota 22R so the thrust surface was in fact a free-floating washer design) because the driver was not very good at changing the oil regularly and rode the clutch constantly. The thrust washer wore out before the throwout gave us any trouble, and when it wore down enough to fall out of it's retaining groove, the crank free-play went from a few thousandths of an inch to over 1/4 inch! To paraphrase Bill Cosby, "And the damage, was tremendous!" Lots of funny noises on that one! Truck only had 40,000 miles on it.

Probably not your issue, but it's something to keep in mind anyway.
And along the lines of disconnecting the trans and running the engine that way, you could also remove any accessory drive belts from the front to see if it changes the noise, or eliminates it. Another test, and much easier to do!

Paul

 

You're correct, but as I understand it the engine is new. so unless something was really screwed up the thrust bearing would have to be fine. this can be checked by simply prying the vibration dampener back and forth.

 

Thanks for all the tips and replies. I confirmed that the growl at idle is coming from the bellhousing. I have purchased a new clutch kit and will be swapping it soon. I did notice that the levers or tangs/prongs that the throwout bearing rides on on the pressure plate are different on this p.plate. These are curved toward the trans, as though to cradle the t.o. bearing. The RAM set that is in there now does not curve like that. (In one place on their site Summit says "NO" it doesn't fit a 4.9, in another place on the site, it say it does fit a 4.9). I can see that the new set would apply more pressure on the throw out bearing and keep it from rattling—I hope! (This trans has a hydraulic slave cylinder that slides on over the pilot shaft and keeps the t.o. bearing against the p.plate tangs at all times.)

The noisy clutch is an 11" clutch. The 4.9 flywheel is drilled/tapped for either 10 or 11" clutch, so I went with 11". But I found that the 11" only came on vehicles over 8500gvw. That makes me believe that other things like the slave cylinder, master cylinder, throw out bearing and/or pilot shaft bushing were also different, depending on whether you had an over or under 8500gvw vehicle. I may have mixed parts. Using RockAuto to distinguish the applications, I've determined which parts may be crossed, and will be replacing those as well. I just want this to work correctly. The new clutch is a 10" set.

Thanks for all the help.