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Vibration problem after clutch install

12K views 11 replies 5 participants last post by  eschaider 
#1 ·
Alright, so I just got done installing a centerforce billet steel flywheel along with a Mcleod prostreet clutch kit.
Pilot bearing and throwout bearing are both Ford and brand new also.


Problem I am having is under no load and during load I am getting a vibration that fades after higher rpms. Kinda feels like an unbalancment of something and then it smooths out higher up in the rpms. Enough of a vibration that it shakes the steering wheel for a moment.


I also bought the clutch kit brand new, but the flywheel came from a guy on corral that had just been resurfaced. Also I noticed the flywheel was much heavier then my stock cobra plate. Would this throw off the balance if not matched to a harmonic balancer?
 
#10 ·
If you don't know the shop that resurfaced the flywheel, you may want to check out the parallelism of the flywheel. I had the same issues (actually the car had shook bad enough around 3500 rpms to make the mirrors blur) and it turned out that the shop I had do my stock fly wheel didn't set it up correctly and the pressure plate surface was .016" out of parallel from the crankshaft mounting surface. I had it blanchard ground and reassembled it with the same orientation and all vibrations were gone.
 
#11 ·
10 years ago, I resurfaced a OEM iron 2001 Cobra flywheel myself on a brake lathe and then I slapped it on my Cobra and ran it up until last month with out a problem. Likewise, I recently installed a McLeod RXT 1200 clutch and McLeod steel flywheel and everything was nice and smooth. I mention all of this because in my view, i would not fool around with trying to balance a clutch or a flywheel in a zero balance application when the correct way to go would be resurface or buy a new flywheel, that way, you don't have to worry about putting the flywheel back in the same spot. By the way, Ford also advises to either resurface the flywheel or replacing it along with the clutch rather than balancing clutch components on a MOD motor in order fix vibration problems.
 
#12 · (Edited)
If your flywheel was resurfaced and not surfaced parallel to the rear crank face you will have one half of the flywheel lighter than the other — because one side is thinner than the other. If there is sufficient material left to resurface it parallel that would be the first step in correcting your out of balance condition. If there is insufficient material to permit a corrective resurfacing, the flywheel will need to be replaced.

Once you have an in-balance flywheel, either through resurfacing or replacement, you still have to resolve the balance of the pressure plate and its cover. It is not necessary to balance the disc. The pressure plate is most easily balanced while bolted to the flywheel. When your shop does the balancing they should look for the light spot not the heavy spot.

Once you shop has identified the assembly's light spot, the balancer will tell them the amount of imbalance and the physical location on the clutch cover. Ask them to select a small steel washer of approximately the required mass and have them spot weld it to the clutch cover. Re-spin the assembly and verify the balance. If there remains a small imbalance repeat the procedure until you have achieved a satisfactory balance.

When you select the washer to replicate the missing mass if you choose slightly lighter than called for the weld material will bring you close to what you need. If you can get a little heavy then an air sander can be used to bring the balance right on. Once you have achieved a balanced assembly use a punch and put two or more prick marks on the clutch cover and the flywheel, adjacent to each other so you can reassemble them correctly later.

FWIW the reason Ford recommends replacement is usually twofold,

a) They sell parts. Like the old saying goes, when all you have is a hammer everything looks like a nail. When your business model includes selling parts there appears to be nothing a new part will not fix. If you have the funds to go down this path it is the easiest fix. All you have to do is R&R the bad stuff and replace it with good stuff.

b) Operating an engine balancer is not part of the training Ford provides for service department employees. Additionally I have not seen a Ford dealership with an engine balancer. The lack of balancing equipment and training in the use of the equipment makes the sale of new parts an easy solution to the problem at hand. An additional benefit is that new parts meet all of Fords OEM specifications so the dealer has confidence in the replacement parts' ability to operate correctly in the customer's vehicle.


Ed
 
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