Cowl shake

Funny thing I noticed now that I'm running the original rims. The car has much more cowl shake than with the low profile tires, which I think is weird.

One would think that the 255/60/15 would yield more thus reducing cowl shake. The ride is less bumpy and more comfortable but somehow cowl shake got worse.

Wouldn't it be logical that the 18 inch low side wall ratio tires would cause more cowl shake because they also make for a tougher ride?

I would think your 'shake' is more associated with the balance of the different tire/wheel combo.

Just my 2c,

Ray

harmonics may be different. It isn't as straight forward as you might think. Try adjusting your tire pressure 2PSI in each direction and see what happens

I also think harmonics: the tires are like another spring in series with the rest of the front suspension parts. Changing the spring rate between the different wheel/tire combos has changed the frequency of the system...

I also think harmonics: the tires are like another spring in series with the rest of the front suspension parts. Changing the spring rate between the different whedel/tire combos has changed the frequency of the system...

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And then you add in the engine and accessories spinning, the belts shaking, and transmission and driveline, and.....

Hmmm, makes sense.

I know it's not a problem with balancing the tires.

Hmmm, makes sense.

I know it's not a problem with balancing the tires.

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Try to balancing the wheels with this, sometimes it makes differences...

Hmmm, makes sense.

I know it's not a problem with balancing the tires.

Click to expand...

Try to balancing the wheels with this, sometimes it makes differences...

Click to expand...

Wow! I've never seen anything like this. I also don't know if anybody around here has one of those.

You could check the run out of the wheels and the tires. It could be the placement of radial cords in the tires causing uneven sidewall stiffness and therefore a vibration of sorts. Does it have less shake above a certain speed? You could reverse the tires front to back to see if the symptoms change. Just ideas. Chuck

It's not a permanent vibration or anything that you would expect from an balanced tires. Also not at certain speeds or whatever.

In fact they are balanced better than the 18 were after they were on the car for two years.

It's just that the road condition and potholes cause cowl shake although the ride is actually more comfortable now.

With the 18s the ride was much stiffer and rougher but it caused less cowl shake. It's somewhat kind of contradictory.

Anyway, I can live with that because a certain amount of cowl shake is more or less normal with those cars and the Magnums are on only temporarily.