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Rattle and Hum: Strange Vibrations

I seem to be getting a vibration when the car is between 3800-4200 RPM - the sweet spot. At first I thought that there was something loose behind the dash, but then I realized that the vibration was in the shifter. In other words, if I would put my hand on the shifter, the vibration could no longer be heard.

Any thoughts? does something need to be tightened, or is this leading to a more serious problem?

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Old 11-30-2003, 07:11 AM
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I've had this same problem roughly between 3500 and 4000. doesn't matter which gear so I know it's driveline related. I've discussed it on this board and the consensus is that it develops over the years and doesn't really point to any mechanical problems. I'll try to look for the thread and post the results here. I do think that I'll be re-doing the driveline once I start restoring the car. perhaps that might help
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Old 11-30-2003, 04:05 PM
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I would say, check your shift linkage first, CJFusco. It's easy to peek at and repair.

Ronin (and possibly CJ if its not the shift linkage), check your lower balance shaft pulley. I can almost guarantee someone installed the face of the pulley 180deg off. I had that same problem due to a JO of a mechanic, and it was making my car run horribly. Seriously, check it out.

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Old 12-01-2003, 06:20 AM
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I go along with the balance shaft pulley error. If you put your hand on the AFS while it is idling then you should feel a slight high pitch vibration along the lines of those huge back vibrators. This will get worse as the rpms are increased. Having one of the pulleys off by a keyway, about 170 degrees, will do this. Could also be the balance shaft belt off a tooth or two.

If this has come on recently then it's worth pulling the belt covers and checking the belt tension and the tension idlers.

Another pulley that comes loose is the cam pulley. There is a socket head screw under the rotor that holds it on.
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Old 12-01-2003, 09:16 AM
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hmmm
i was one of the ones to take part in the timing belt party a couple weeks ago. it started not long after that
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Old 12-01-2003, 11:04 AM
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Quote:
Originally posted by mrmunky
Ronin (and possibly CJ if its not the shift linkage), check your lower balance shaft pulley. I can almost guarantee someone installed the face of the pulley 180deg off. I had that same problem due to a JO of a mechanic, and it was making my car run horribly. Seriously, check it out.
that would be nice were it to be true. however, I have my doubts as the problem did not start right after the last timing belt change. it developed gradually a while afterwards

HOWEVER, as the saying goes, thou shalt leave no stone unturned. so I'm still going to check all possibilities
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Old 12-01-2003, 01:07 PM
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Shift linkage is more than likely your easiest/quickest route for a hopeful quick fix. Either way good luck and keep us posted!
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Old 12-01-2003, 09:07 PM
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Quote:
Originally posted by SoCal Driver
I go along with the balance shaft pulley error. If you put your hand on the AFS while it is idling then you should feel a slight high pitch vibration along the lines of those huge back vibrators. This will get worse as the rpms are increased. Having one of the pulleys off by a keyway, about 170 degrees, will do this. Could also be the balance shaft belt off a tooth or two.

If this has come on recently then it's worth pulling the belt covers and checking the belt tension and the tension idlers.

Another pulley that comes loose is the cam pulley. There is a socket head screw under the rotor that holds it on.
jeez. why didn't I notice your post before. seems like you were answering me before I posted. come to think of it, didn't this happen before?!?
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Old 12-01-2003, 09:43 PM
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CJ;

I wasn't looking over everyones' shoulder when your balance belts were put back on, but you saw how they were supposed to line up. There is a good diagram on Clark's Garage website, and perhaps you could relatively easily verify the balance belts before digging into them again. Seems to me you have the non-power steering white '83? It's a little easier to see, there are holes in the plastic covers that line up with the balance shaft marks as I remember. Get the engine to #1 TDC and sight thru the holes in the cover at the balance shaft locations.

I caught a nasty flu bug from nieces and nephews last week, and am still on the mind-altering drugs, but seems to me the early cars this can be done. Pay close attention to the instructions for checking the shaft positions in the Clarks' site, and let us know what you find.

I would tend to agree with the shifter linkage idea especially because as it gets colder(like it has in Boston), those bushings get hard, and pass along vibes. I would think that the shaft imbalance would have been there all along.

Do let us know!


EDIT:

I went back and re-read the entire thread, and seemed to remember something else. Weren't you the one with the stripped rotor screw? Did you get that replaced? While you're there, you could check the cam pulley, but be careful not to stress the belt. You're just looking to see if everything is tight.

Keep us all posted.
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Last edited by singpilot; 12-02-2003 at 05:38 PM..
Old 12-02-2003, 05:34 PM
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Thanks guys; I will check the shift linkage first, for obvious reasons

Singpilot - yeah, that was me with the stripped rotor screw... haven't had time to do anything about it yet, with work full-time and grad school... i will get to it soon, though...
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Old 12-03-2003, 06:53 AM
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Quote:
Originally posted by CJFusco
Thanks guys; I will check the shift linkage first, for obvious reasons

Singpilot - yeah, that was me with the stripped rotor screw... haven't had time to do anything about it yet, with work full-time and grad school... i will get to it soon, though...
do u need me and mike to look for kerosene again to work on ur car since it's damn cold....

Old 12-03-2003, 08:28 AM
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