hood shimmy

[Dibbons]

Noticed this on my parents new '71 RR back in the day and currently on my '72 SSP project car, at certain speeds/highway road conditions the hood starts to shake/vibrate a little left and right (when closed obviously). I was just wondering if this will be a constant "defect" or if anyone has eliminated it completely by balancing the front tires, rebuilding the front suspension, wheel alignments, etc. ?

 

[Grabinov911]

My '70RR did the same thing. I was unable to adjust it out after many attempts, and finally put hood pins on the car. It was only mildly annoying at 60, but at higher speeds it was concerning. I've seen a car wrap the windshield over the hood at high speed. Granted, in my case, that would require overcoming not just the hood catch, but the secondary hood latch which is there to prevent exactly that, still - unnerving.

I have no idea what causes that particular wobble, as I don't see or feel it anywhere else on the car.

That's a cool looking car. Love that orange...

 

[72RoadrunnerGTX]

That's why fender struts were added to big block cars in '72.

 

[Grabinov911]

Not to be argumentative, but on my car, the hood moves RELATIVE to the fenders. The fenders don't move. The hood does. I've never seen the fender struts though. Were THE FENDERS moving in that car?

 

[72RoadrunnerGTX]

Hood movement relative the fenders is controlled by the spring loaded wedges in the rear and the rubber wedges toward the front. If these are not in place and/or functional there will be excessive movement relative the fenders. If the hood to fender gaps are too wide, the wedges will not be effective. Fact remains there was a design change for this body platform beginning in ’72 adding cross bracing to the front fenders with some engine combinations to control lateral movement of the fenders and hood. As with any other production design change, the expense (however small) to make this change would not have been undertaken if a problem wasn’t perceived to exist. The struts were carried forward during the following model years.

 

[Bruzilla]

Those struts were on SB cars also.

 

[72RoadrunnerGTX]

Not in '72

 

[Bruzilla]

They were in 73/74.

 

[Dibbons]

Now here is a good question, do those with 73-74 small blocks experience the "shimmy" even with having the factory installed struts?

 

[Dennis H]

Do 71's have these bumpers?

 

[dangina]

Do 71's have these bumpers?

View attachment 331065

u betcha!

 

[idrivemopar]

Now here is a good question, do those with 73-74 small blocks experience the "shimmy" even with having the factory installed struts?

No Shimmy ever on my car, small block with strut rods, and the rubber bumper on the front location of the fender and the spring loaded one on the rear of the fender. This side view shows both, the spring loaded one is visible just behind the hood hinge.