Clutch vibration

[tbone1471]

I am chasing a vibration and I think I have it narrowed down to the clutch. It's a Mack e7 with an eaton 8ll.

It has vibrated since the clutch install. Brand new eaton easy pedal. It seems to have gotten worse with a few miles. I think we have less than 3000 on it.

It doesn't matter if the clutch is pushed in or out it will vibrate. I removed the clutch to flywheel bolts and the vibration is significantly less. Possibly non existent and I just want it to be something other than the clutch.

Has anyone ever gotten a clutch that wasn't balanced properly? Eaton says no way it's the clutch....

My biggest concern is that it could break the crankshaft or take out the transmission.

Any other ideas?

 

[Tenwheeler]

I had that problem with a 3406 easy pedal. The shoulder on the clutch mounting bolts bottomed on the flywheel before the pressure plate was tight on the flywheel. Try shorter shouldered bolts or washers before you pull it like we did. We did have the flywheel surfaced and the bolts did not work anymore.

 

[funwithfuel]

Did you resurface the flywheel, did you do it yourself? Send it out? I got saddled with an exchange flywheel once that was bent. N14 15.5" , No vibe prior to clutch, horrible vibe afterwards. found it with a dial indicator.

 

[tbone1471]

I have my local truck shop resurface our flywheels. It was the same 1 that came out of the truck. They have done many for me with no problems.

The clutch works fine. No slipping. Everything is perfect except for the vibration. You cannot feel it vibrating in the clutch pedal. It just shakes the whole truck. This is why I am so concerned.

 

[funwithfuel]

14" or 15.5" If 14, any chance a drive lug is not set properly or perhaps missing? That's a big chunk o weight.

 

[tbone1471]

15.5"

 

[RZucker]

If you had your flywheel refaced I think you better check it with a dial indicator and make sure you don't have any garbage between the flywheel and crank flange. I saw a case where a guy put a new flywheel on a Cummins and didn't clean the paint off the crank contact surface. That was enough runout to ruin the clutch before it backed out of the shop.

 

[funwithfuel]

So that rules out the drive lugs. Pilot have the correct ID? I know that sucks to think about, OH CRAP ! did you use the 2znrj one with the snap ring on it? If you did , did you remove the snap ring? That thing has screwed more than a few guys.

 

[tbone1471]

I would think if there was an issue with how the clutch seated I would feel it in the pedal. Similar to a pulsing feeling. Also there is no clutch slipping at all.

 

[funwithfuel]

6306 with no snap ring for mack engines. If you use 6306 2ZNRJ you might have a problem

 

[tbone1471]

I never thought about the pilot bearing being right.

We have 2 identical trucks and both got easy pedal clutches within a week of each other. Same clutches installed in both trucks. One thing that does come to mind being that everything is the same. The truck we are having an issue with has a softer pedal than the other truck. But we are not missing any springs. Also I would think if a spring broke off a disk it would jam in the clutch. Had it happen...

 

[funwithfuel]

I get what you're saying. I'd check your parts list and make sure its a straight 6306. You could be putting undue strain on your engine thrust bearings. You could go through the inspection hole in the flywheel housing and pry the flywheel forward and back. You should have some travel .007"-.015", .015" being extreme. If she don't wanna move , you know where to begin

 

[funwithfuel]

typically , when a damper spring fails, your pedal falls to the floor the first time you disengage the clutch. That little booger drops out in between the plate and disc or flywheel

 

[tbone1471]

I took videos of the vibrations. Maybe they will help

 

[funwithfuel]

Well, that speaks volumes. Did you replace the input shaft? Were there steps in the splines? Clutch brake one, two or three piece? Ones and threes are trouble free, that two pieces pivoting thing has been a little goofy, but not like that. What about the shipping blocks between the throwout and pressure plate, were they accounted for? And you got your proper clearances? 1/2" at brake, 1/8" fork to T/O and 2 to 2 1/2" free travel?
I know you sound like you've been down this road before, but I have to ask.

 

[tbone1471]

I did not replace the input shaft. The splines were straight and it didn't have any appreciable wear.

I put in a 1 peice clutch brake.

Wooden shipping spacers were removed.

1/2" space btw the throw out bearing and the clutch brake and 1/8" between the ears and wear plates on the bearing. Free pedal is 2".

Am I just crazy or do you think I'm blowing this out of proportion?

Eaton doesn't have any interest in warranty. Our parts supplier stated that we would probably end up eating the clutch because eaton will say they can't find an issue... and we are not going to put the truck down for weeks while they inspect it.

 

[funwithfuel]

No , I don't think there's an exaggeration on your part at all. That video clarifies a lot. The water bottle shows all that needs to be seen. I still have concerns with the pilot, that said, I don't think that is your problem. It's almost sure to be in the pressure plate. Are those torsion leafs in place for the center plate? none broken or bent. Unlikely I know. IS it a button clutch? Are the buttons stacked like they're supposed to be? If they're staggered on the shaft , that 'll cause an imbalance on the shaft when clamped under the pressure plate. Stuff to kick around.

 

[RZucker]

Pull it all out and check the flywheel runout. If it vibrates with the pedal in or out, it has to be related to that. If the flywheel has no runout then... possibly the clutch cover is out of balance or the clutch was stacked wrong. You wont feel it through the pedal, the vibration is coming from the outer rim of the clutch, a few thousandths is all it takes to make that 175lb clutch wobble badly. Honestly I have never seen an Eaton clutch have any issue that wasn't installation related. On the other hand I've seen some cheapo rebuilds come apart fairly soon after installation.