409 Vibration at takeoff

[shaun1958]

:( Whenever the 409 gets driven, it shudders at launch. It does it most prominently in first gear but does it in all four. The car did when it was put away over 30 years ago and after being rebuilt last year it still does it. Everything in the car is new or rebuilt. Two new clutches were tried and the pressure plate looks good. Is it the shims in the rear. If so how much does the pinion angle have to be out to have a vibration.

[jim_ss409]

Quote"Is it the shims in the rear. If so how much does the pinion angle have to be out to have a vibration."

Shaun, The answer is not very much. I had a similar shudder in my 64 after a tranny swap. It took less than 1/4" of shiming under the trans mount to completely eliminate the vibration. If you've got a shop manual it will list the proper driveline angles.
By the way, I see you're in Thunder Bay Ont. That's where I'm from too, :cheers but I moved away about 20 years ago. I usually get up there in the summer to visit my parents. This year I'm hoping to drive up with the 62, if I get it done in time.

[shaun1958]

Quote"Is it the shims in the rear. If so how much does the pinion angle have to be out to have a vibration."

Shaun, The answer is not very much. I had a similar shudder in my 64 after a tranny swap. It took less than 1/4" of shiming under the trans mount to completely eliminate the vibration. If you've got a shop manual it will list the proper driveline angles.
By the way, I see you're in Thunder Bay Ont. That's where I'm from too, :cheers but I moved away about 20 years ago. I usually get up there in the summer to visit my parents. This year I'm hoping to drive up with the 62, if I get it done in time.
Hey Jim. When in September do you think you might come up? We have our annual fishing trip for 4 days the weekend after labour day. We wanna see the car if you do come up. We'll have one or two :cheers and maybe cruise a bit.

[jim_ss409]

Shaun, I'll be sure to contact you when I get a better idea of when I might get up there. I usually try to get there duing July or Aug. I'd really like to see that Impala I used to have one like it, but it wasn't as nice. I'm voting everyday but that Dodge is still in the lead. :cuss http://www.musclecarplanet.com/Show/Show.htm By the way, that "See you in Sept." is part of my signature and it refers to the 348/409 convention in kansas City this sept. I intent to get there too.

[MK IISS]

:( Whenever the 409 gets driven, it shudders at launch. It does it most prominently in first gear but does it in all four. The car did when it was put away over 30 years ago and after being rebuilt last year it still does it. Everything in the car is new or rebuilt. Two new clutches were tried and the pressure plate looks good. Is it the shims in the rear. If so how much does the pinion angle have to be out to have a vibration.

Shaun: Have you checked the split driveshaft center carrier?

[shaun1958]

Thanks for the reply Richard. All I can say is the center carrier and bearing were replaced but the driveshaft will be coming out in a few weeks to prep the car for summer. We will check the carrier along with pinion and trans angles to see if the problem can be resolved. Thanks again