I'd appreciate any help: Car: 235 6 cylinder, factory 3 speed overdrive, front harmonic balancer has been drilled and taped w/crank to accept a bolt to hold balancer on. Put car up for 3 years due to disgust over paint issue. Got it back out. Notice a vibration that I don't remember being there before. When I got the car back out, I installed a new clutch and turned the flywheel/pressure plate because it used to have a rear main leak that had soaked the old clutch and caused shuddering after it warmed up. New clutch fixed that problem (I had fixed the leak a while back). Car idles fine, but rev it just off of idle while sitting still (clutch in or out) and it has a bad vibration. Also, if you are winding it up to shift through the gears, it shudders, getting worse as the revs seem to go higher. Shifting into the next gear the vibration goes away until the revs reach a certain point. On the highway, I can be in 3rd gear and it will have a vibration until I shift into 3rd o/d. The lower rpm causes it to go away, or at least become unnoticeable. Could the new clutch installation have caused this? The flywheel will only bolt on one way, so I don't think it would be off. The carb is in need of an overhaul and is leaking some fuel and runs rich. One of the spark plug wires had a broke fitting (cut to fit) and I had to replace it with a new one. Could fuel or ignition cause this kind of vibration under these circumstances? One fear I have is that the bolt hole in the crank wasn't drilled exactly center and it could be a cause. I've checked and from what I can tell the motor mounts seem to be good. I'm afraid this vibration may be wallowing my main bearings or causing other issues. Thanks,
The hole in the crank is filled in most of the way by a bolt of the same density of the crank. Even off set, it is still very close to the center of rotation. I had a flywheel resurfaced once that came back with a tilted face, and thus unbalanced. I believe the flywheel was not sitting flat on the machine table and a cut was made and put a taper in it. It vibrated. could not see the problem but we measured the runout.
However silly this may sound you need to do a few checks before tearing back into the clutch. First remove the fan belt and run the engine to see if the vibration still happens. That would eliminate any vibration coming from the water pump, fan, or generator. Next using a timing light on each spark plug wire will tell if a cylinder is misfiring as the rpm's increase. A few simple checks could save a lot of unnecessary work.
From what you say the vibration is in time with the engine (drops off when you shift into high) which suggests engine flywheel or clutch and not driveline or wheels. As it only started when you replaced the clutch that points to the clutch or flywheel. I don't know what is wrong but that is where I would start looking.
He originally said..."Put car up for 3 years due to disgust over paint issue. Got it back out. Notice a vibration that I don't remember being there before. When I got the car back out, I installed a new clutch and turned the flywheel/pressure plate...." Sounds like the new clutch was installed after feeling the vibration.
From the state of the tune I would start there (you said the carb runs rich and plug wire problems) If it has been sitting how good is the gas?
Yeah, the sequence of events is unclear. Mostly if the vibration happened only after the refaced flywheel and different clutch was installed. Got a tach? If you rev it up in neutral does it vibrate? When driving at a shaky mph, what happens (vibration wise) if you step on the clutch and let the motor idle? If driving at a shaky mph, what happens if you accelerate (vibration wise) but before the speed changes?
Thanks for the replies. I'd never really thought about the bolt filling the space and only being offset like that before, but that makes sense. Would taking a dial indicator reveal if the flywheel is off, or would I have to remove it? Thanks for the advice Kentuckian. Man, it seems so obvious, but I have never thought to use a timing light on each cylinder before. Man, I can't believe that never even occurred to me. Thanks for the tip. I'll try that and also removing the belt. I don't remember the vibration being there before, but I cannot be 100% certain. In the past, there was a rear main seal leak, which had caused the clutch to become oil soaked. When the clutch would get hot, it would shudder real bad when I would release the clutch pedal. I fixed the rear main seal leak, but it didn't fix the shudder because the clutch had been soaked. I fixed the rear mail seal and had a guy mess up my paint, got disgusted and put the car away for 3 years. When I got it back out, before I drove it, I installed a new clutch and had the flywheel turned at an engine shop. The car will shudder when stopped with the clutch in or the clutch out. You don't really notice it when idling, but if you bump the idle up to like 1500 or so rpm it has a bad vibration. (I notice this because the rochester bc carb (original style 1 barrel) has a warn throttle shaft and will often stick at 1500 or so rpm until I stab the throttle, then it settles down to normal idle). Along with vibrating at a stop with the clutch in or out, it also does so anytime I rev the engine, like shifting through gears. What's strange is that the vibration is bad at idle when it's around 1500 or so, but if I get it out on the road in overdrive I can be over 1500 and it isn't bad at all until I get into much higher rpm.
Is the damper bolted on because it come loose before ? Surely it isn't crooked or you would have seen it. You can pull the plugs & dust shield to check for flywheel runout - screw a wire to any handy bolt as a steady rest & hook up a remote starter. My money is on clutch imbalance - if you kept the PP you replaced, try sticking it back in. You can run it on stands with the trans out & it'll tell you if you're on the right track.
Are 235s from '57 internally or externally balanced? I'm going to try to remove the clutch and pressure plate first. If that continues, I'd like to remove the flywheel and run the engine, but if this engine is balanced by the flywheel I guess that wouldn't do any good. I got a new harmonic balancer a while back, but the keyway on the crank wasn't as tight as I'd like it to be so I bolted the new one on.
When you replaced the clutch did you replace the Pilot Bearing (or bushing) in the end of the crank? If it is excessively worn, it will allow the front transmission shaft to be installed misaligned and thus the clutch plate is off-center.
Worn keyway may indicate loose balancer at one time. If it's still loose, that's a suspect. Back off your "balancer retaining bolt" a turn or 2 & check for looseness.
Look at the damper with the engine running to see if it wobbles. I did the clutch in my Ford and had the flywheel balanced with the clutch plate, new TO bearing and pilot bushing.
Seems this O.P. is not responding lately, but I'd like to know if the "replacement balancer" was a new balancer or just new to the O.P. Either way, the replacement balancer could be the problem, especially if the O.P. thought the balancer needed to be bolted to the crank.
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