Vibration/balancer problems

1st Official Post

    I have had a slight vibration at idle since I rebuilt my 289 hipo. Well, I finally took it to a well respected mechanic to fix a pesky oil leak. He noticed the vibration and offered to help with it. Well, he called me today to say that he suspected the balancer. He suggested I replace it with one of the newer fluid filled models. I explained to him that the balancer is one of the more noticeable and important features of a K-code. With that said, how can I tell if it is in fact the balancer. I know that they can slip. Is the keyway aligned with top dead center as marked on the balancer. If so, shouldn't I be able to tell if it has slipped by looking at the markings on the outside of the balancer relative to the keyway. Any other suggestions would be greatly appreciated. Thanks

    Ditto the recommendation for Damper Doctor. John's shop is right down the street from my house. He does great work for restorers all over the world.


    Damper Doctor

    1055 Parkview Avenue, Redding, CA 96001

    (530) 246-2984


    I would be a little suspect of a damper as the cause of slightly rough idle. A damper that is in need of repair shows some tell-tale signs like cracked or missing sections of rubber, and can be misaligned at the timing mark, though not always. The vibration will generally be present (or even worse) as you increase speed.


    Edited by - round2K on 02/05/2007 19:28:15

    • Official Post

    The keyway is not aligned with the TDC mark on the balancer. However, if you align the balancer TDC mark to the timing cover pointer the keyway will be at 12 'o' clock. Most vibrations that I have encountered relating to balance issues showed up at mid to high RPM. I had a vibration at mid and higher RPM's on mine. I too suspected that the balancer outer ring had slipped. When I went to remove it the balancer came off with no more effort than pulling on it with my hands. It turned out that the snout was cracked enough front to rear to break a section out of it. As long as it was bolted on it stayed together and still sealed without leaking oil. It was not salvageable once removed and the crack in the snout was making the balancer have a slight wobble causing the vibration. So much for a tough to find C5OE balancer. All this said, I realized that even if the ring had slipped, the only problem would have been the timing mark because it is the same mass all the way around. If your balancer has not been drilled for balancing on the outer ring, the position of the ring is not going to affect the balance. However, I see many balancers that are balanced after the original production during a rebuild that have been drilled for balancing the engine. Worse yet I have seen balancers drilled almost to the point of being ugly to create a balance without the front counterweight. Those would definitely cause a problem if they slip.

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

    FROM WORKING WITH NVH CONCERNS AT THE FORD DEALERSHIP ONE OF THE FIRST THINGS TO ELIMINATE FOR VIBRATION DIAGNOSIS IS A WORN OR LOOSE ENGINE OR TRANS MOUNT ,CORRECT FIRING ORDER, LOOSE PULLEYS.


    Edited by - chucks302 on 02/05/2007 22:11:36

    Thanks for the tips. I really don't want to have the balancer rebuilt only to find out it wasn't really the problem. So, has anyone had this kind of vibration and solved the problem? The vibration is most noticeable/visible in the steering wheel. The engine doesn't visibly vibrate (weird). Could be the greater mass. The motor mounts and transmission mount are new. It used to be worse, but I changed the transmission mount (stock) and that seemed to improve it. The vibration seems to go away off idle, but it could just be less resonant at higher rpms. Could timing (too much) cause a vibration? Any other suggestions would be appreciated?

    Check to see if any part of the exhaust system is touching or grounding,to the body or frame of the car transmitting engine vibrations,out of balance cooling fan, also a new engine or trans mount could also be a source of a vibration if it is not neutralized to the frame,bring the engine up to operating temperature ,losen the right and left motor mounts and rear trans mount, put the trans in ist gear power brake lightly, put trans in neutral goose the throttle ,put the trans in reverse power brake lightly, shift back to neutral and goose the throttle again, then retighten the motor mounts and rear trans mount, then recheck to see if it improved.

    Use CAUTION when using a Fluid Dampner!!!! In cold weather than can break or worse yet is break your crank!!! Ford Racing sells a very good balancer for your HIPO. It is almost the same thickness. You may have to modify a crank pulley to fit. They come with three bolt and four bolt pattern. They are 28 oz. units. Which bolt right on. Also did you have your pressure plate checked and was it rebalanced? The shop that rebuilds your engine can put the pressure plate on the balancer after he has balanced your crank assembly and check to see if your pressure plate is in balance. It should have been neutrel balanced already. When rebalancing your HIPO engines don't let them drill on the balancer or flywheel. Do all the correcting on the crankshaft. I have repaired cracked balancers! I weld them after they are taking apart and then machine them. Never had one break after doing that. I have also machined the end off the balancer and used a FE crank spacer machined to the correct lenght and use a full lenght key. That works fine also.DON'T THROW AWAY YOUR OLD HIPO BALANCER, I fix them if they are cracked. I leave the rest up to the Dampner Doctor.Hope this helps. Ron

    I am probably way off on this one, but I also had a vibration in steering when I purchased my 'K', along with steering being harder to turn than it should be. Found that someone had installed the clutch spring incorrectly and it was rubbing up against the Pitman arm. Installed the spring properly and it hasn't bothered me since. You're problem may be similar or totally different, but it's always good to look for the simple solution first.

Participate now!

Don’t have an account yet? Register yourself now and be a part of our community!

Register Yourself Login