Body vibration at 60 mph in the 71 cuda

[67Vette427]

I agree, the Mopar Performance springs leave something to be desired... made in Mexico.... Good tip on t he Eaton's! Thanks

The driveshaft is out and now the vibration is gone. I'll go grab my brother's driveshaft out of his 440 dana car tomorrow.

[Alaskan_TA]

Have you checked your drive shaft with a straight edge yet to see if it is bent? 

[Street_Challenged73]

I agree, the Mopar Performance springs leave something to be desired... made in Mexico.... Good tip on t he Eaton's! Thanks

The driveshaft is out and now the vibration is gone. I'll go grab my brother's driveshaft out of his 440 dana car tomorrow.

That sounds pretty good for you, 67Vette.  That driveshaft is most likely your problem. (if not, at least it's contained to just the rear end now.)  As for those MP springs, too bad you didn't looking into Eaton's or Espo's first.

[67Vette427]

The driveshaft is straight with a straight edge on it. The u-joints are spicers and look good. The only thing I could think would be wrong is maybe one of the yokes are out of alignment.

[Street_Challenged73]

Hmm, maybe Chryco or Shelbydogg will know of a possible problem with something back there.  I'm stumped considering the third member had been rebuilt earlier....Perhaps it is your axle bearings or possibly a bent axle shaft.  You wouldn't think the rebuilt part would be your culprit.

[ShelbyDogg]

Have a driveshaft place check your joints and indexing, before rebalancing it. A cheap u-joint not centered by a couple of thousands can cause that vibration.  Great Troubleshooting Vette.
Rob

[67Vette427]

Its got Spicer in it and they look and feel good. All the bearings are there. If there is a problem maybe its with the way they welded on the yoke but then you would have thought they would have picked that up when they balanced the shaft a couple months ago.

I found a good read on driveshafts and angles :http://trailer-bodybuilders.com/mag/trucks_thorough_driveline_inspection/index.html

Also, if any readers need the driveshaft dimensions for a Cuda the length is 43.60" 4 speed/auto car 340 and bigger motor with a 3.25" diameter. The Dana cars are just an inch shorter at 42.60" That Dana is a monster...

Thank Rob and all the others for the help...

[ShelbyDogg]

I guess you need to put you brother's driveshaft in to see if the vibration is there.  You did say in a prior post that you heard squeaking in the pinion area. If your driveshaft fits your brothers, get his car on the highway at 60 and compare the vibrations.  You almost have to tell the driveshaft company that the shaft is out of balance.

[67Vette427]

It looks like I found it. After Rob mentioned the U-Joints I thought I'd take a closer look at them, even though I did before and Bayshore truck did also when they balanced the shaft. Well there was a little bit of play in one. The front joint was a Spicer but not the rear. I replaced it with a Spicer today and put the shaft back in. Now the car is smooth, even with the wheels on but its still up on the stands. I found a broken muffler hanger thats been making a ringing noise at stop lights so I going to fix that now. Anybody got some Super Glue      Thanks for all your help, especially Rob. Without the extra ideas I may not have checked things again that were checked before.

[Oldschool]

Congrats 67Vette...       Hope it runs smoothly from now on.  You are living proof that perserverence pays off. 

[Bullitt-]

Amazing, how often it turns out to be the simplest thing. Glad you got off that easy.   

[Autophile]

Glad to hear it. Now go enjoy your smooth ride. 

[ShelbyDogg]

Glad you found it Vette.   But give credit where credit is due also.  You Omitted everyone else that helped in that last post. Bullit, Alaskan, Chryco, Autophile, Redtop, Street, and everybody else that posted suggestions also helped. We all kept saying the same things to check, that finally got it.   

Happy vibration free speeding....   

[Street_Challenged73]

Glad you got the problem figured out, 67Vette427!   Go have some fun with the car now without anymore problems.

[67Vette427]

Took the Cuda on its actual road test today and smooth as glass. With that 833 OD trans what a great road car. Here's a picture of the Cuda coming back. She looks much happier!  Thanks to all who took the time to offer comments!