Howdy I just recently put a new clutch in my 93 f150 with a 4.9L I put a new slave cylinder in so I wouldnt have to pull the tranny again when that crapped out I also had to turn the flywheel down and then shim the flywheel after I put it all together again there was significant vibration from the flywheel at a bout 2000-2500 RPMs. I have looked all over the internet to find so info on the subject but have not found anything. When I took the flywheel off I didnt mark it so I belive that it is out of balance because of it. but i have done clutches in chevys and toyotas and never mark the postion of the flywheel and I thought they balanced flywheels by themselves if anybody has info for me I would really appreciate it. Thanks.

 

The flywheel on the 4.9 is neutral balanced.

I just rebuilt my 4.9L. The new pistons were over 20 grams heavier than the originals. Because of the weight difference the machine shop recommended the rotating assembly be rebalanced. They did not need the flywheel. They only needed a rod bearing, the rods, pistons, crankshaft and front damper.

The service manual doesn't mention the need to mark the position of the flywheel in relation to the crankshaft before removal.

What did you shim out?

Is it a no name clutch assembly?

 

The Clutch Kit I got was just a napa one and I belive I shimed the flywheel out .025

 

Can you feel the vibration while you rev the engine with the transmission in neutral?

Can you feel the vibration while you rev the engine with the clutch pedal engaged?

Did you install a new pilot bearing?

Did the machine shop tell you to install the shim?

 

Yes you can feel it in neutral and when the pedal is engaged I did install a new pilot bearing and the machine shop did tell me to shim the flywheel before I had the flywheel turned I had the vibration and I though maybe that was the problem so I had it turned and I still had the vibration

 

Not sure I understand the problem.

You installed a new clutch disk, pressure plate, pilot bearing and clutch slave.
After the installation you had a vibration and the machine shop told you to install a shim.
You pulled the trans. installed the shim and had the flywheel resurfaced but that didn't cure the vibration.

If the vibration is there when the clutch pedal is engaged, that eliminates the pilot bearing and clutch disk.

With the clutch mechanism being hydraulic, I don't see the need for a shim.

If the flywheel is seated on the crank flange and you torqued the bolts in the proper sequence my guess is you need to remove the flywheel. Take it back to the machine shop to verify both the flywheel and the pressure plate are neutral balanced.

 

Yes - what exactly did you shim? It's not necessary on a hydraulic clutch truck to shim anything.

Also - the 4.9L flywheel is NOT neutral balanced. However, it only goes on the crank one way, unless you drill the mounting holes out.

 

O ok so I should marked the flywheel then when i took it off becuase it is not neutral balanced? Right

 

The flywheel bolt holes can only line up to the crank hub one way due to the way the holes are drilled so that's not your problem.

If the machine shop returned your original flywheel your problem points to the clutch pressure plate being out of balance. If they exchanged the flywheel you may have the wrong flywheel for your engine.

As for the flywheel balance, as far as I know it's neutral balanced and uses no fixed value external counter weights.

The flywheel on some Ford engines have a fixed value external weight either bolted to the flywheel or welded to the flywheel. I don't believe your year 300 falls into this catagory.

 

If there is no balance on the flywheel (I guess there wouldn't necessarily be one in a straight engine) then why does the flywheel only go on one way?

 

A question only Ford could answer.

The Porsche flat six engine is the same way. The flywheel can only be installed one way and it is a factory internally balanced engine.

I spoke with the guy at the machine shop I use. He said he has seen new clutch assemblies that are out of balance.

 

I am not used to flywheels being balanced on Fords, never had an issue on other makes but alas I removed my flywheel in the process of a clutch job, to put a rear main seal on (trying to do things right) and wouldn't you know It, I put the flywheel back on out of synch with the mounting holes, .. long story short. I drilled out 2 holes and tapped them to next larger size bolt to get the last 2 bolts in. After finally finding a Ford clutch man he tells me unless I realign back to original 6 hole bolt pattern, the motor will vibrate to pieces because of the flywheel being out of balance.. But He could not tell me without looking how to go back to that original pattern. Should I be worried or just let it go .. I just want to do it right (this time). So I figured this would be the place to get some straight dope on this situation thanx in advance for your help (and prayers) .. (I'm getting to old to do this in the dirt again,,, Lol God Bless Chas

 

Yes you screwed up and you need to take the flywheel off and install it correctly.

 

yes I know I screwed up now I confess it now tell me how to install a new flywheel correctly then someone please thanx God Bless Chas

 

Even though you drilled out 2 holes on the flywheel, you should still be able to tell how it should have went, I would think. But you might be better off getting a different flywheel so you don't have 2 loose holes, maybe a new one if available at a reasonable price.

Reading what you said under #12 I hope you didn't drill and tap into the engine crankshaft?

When you install the flywheel, make sure to tighten the bolts even so you get it square.