djones66gt

I'm definite newbie and could use some help.66gtconvt with 4spd, A code. Restored about 25 years ago, appx 92K original miles.When I bought the car three months ago,knew about the "chatter" as the seller and two people who checked the car out (one club member and one professional) all thought very simple fix of either new clutch kit or turning of flywheel would do the trick. Based on records, clutch and pressure plate were replaced about 2000 miles/3 years ago, (not by seller but by owner who had done the restoration) so this is not a new issue.When releasing clutch pedal on any kind of an uphill incline,can get anything from mild to moderate "chatter" to a "violent shudder" bad enough to rub body panels together. Replaced clutch, pressure plate, throw out bearing, pilot bushing and flywheel...no change. Next recommendation was input/output bearings sohad re-build done (rebuilder indicated that original bearings were actually pretty good, but still replaced) and, at his recommendation did a second clutch kit (LUK) std equip , not Heavy Duty...problem is still there. Willing to listen to ANY IDEAS at this point. Problem only occurs in first gear (I can start in second gear with no issues). The car is drivable, but would obviously llike to get this corrected. Sorry for the long ramble.

67mustang302

What clutch did you use? Get a real one like a Centerforce or a Spec etc. Those weaker factory clutches slip/chatter quite a bit in some applications. This is of course provided that it's not from oil due to a rear mainseal leak.

djones66gt

Thanks for checking in. First clutch was a Sachs, second (current) one is a LUK. TRans guy"swears" by Luksaid a centerforce or very heavy duty clutch could have been part of the problem....found an old thread under search for "clutch chatter" and the symptoms were exactly like mine. Couple people have checked the motor mounts and Trans mounts and they checked out. Its been apart twice now and no one has said anything about leaks

Reverb

Could be oil on the clutch, that will cause chatter. If the crank oil seal is gone or if there was oil on the flywheel then that will cause chatter.

Oxnard Montalvo

I would check the motor mounts. Accelerate hard and see if the shifter moves to the right.

The possibility of "Operator Error" is also a consideration. The 289 is not really a torque monster so smooth engagement with some rpms, especially on a hill, is an "art."

Starfury

You still shouldn't get that kind of chatter.

As has been said, take a look at the motor mounts. Also, look at the shifter linkage, specifically the z-bar bushings. If the bushings are shot (or gone), the z-bar will be able to move laterally in between the block and the fender, causing exactly the problem you're having.

jravenea

I have a similar problem, not that bad though.

So far I have replaced the bushings and felt joins of the Z-bar. I also spent quite some time adjusting the clutch. It has improved but chatter is still there.

I believe the hard clutch linkage should be part of the problem. My next step is to replace bellhousing and install a cable linkage.

'Operator error' is indeed a parameter. I've been driving manuals all my life. Last time I let a friend of mine drive the car and he burnt the clutch... However even for me the clutch is un-easy to operate.
By the way, my car is a coupe 68 / 302 / T5 swap

67mustang302

Some clutches can just cause chatter in some cases simply because. I went to a Centerforce way back when BECAUSE of clutch chatter, and it went away. I've never met anyone with a Centerforce Dual Friction or a Spec that has had clutch chatter, even in insanely high horsepower applications. But yeah, engine mounts etc need to be checked as well. Also try checking the transmission mount.