Hey y'all!

[ShrinerKen]

New from South Carolina here. How do y'all like my rat rod toy? She's a '46 Ford on a '91 S10 frame. She scoots around nicely with that TBI V6 and the auto tranny from that S10. The bed is hand formed and she rides on early E.T. mags. Speaking of ride, has anyone dealt with the shakes and hops? I went in circles trying to rid this rat of it's trembles. From balancing and alignment, to shock and spring replacement and a steering stabilizer, to praying to the Voo-Doo gods....no avail. Then one day while reading motor head threads on rat bikes (go figure) I read a discussion about tire pressure. After experimenting with lower pressures I dropped the psi from 32 (which the local tire genius said they should be set at) to 22psi in front and 18psi in the rear sneakers....PRESTO! Smooth as silk. Anyone else used this fix? Sometimes it pays not to listen to "certified " specialists and rely on the good ole boys tweaking skills!

 

[rainman]

Welcome to the site!!

My guess is by lowering the pressure you're just masking the problem!!
With more info the guy's on here can probably help you solve it!!

BTW Nice truck!! Got a 46 myself!!!

 

[Gus]

Welcome to Triple R.. I agree ur just masking the problem with lowering the pressure. But as we say EVERYTHING is fixable.

 

[Sam_Fear]

Welcome to RRR! Cool ride.

 

[rustybeercan]

Welcome to the triple R!

Beercan

 

[ShrinerKen]

Masking?

Perhaps. I'm open to suggestions. First the wheels were checked for out of round and balance. Same goes for the tires. The front wheel bearings and rotors were also checked. The shocks and springs in front were replaced based on the lighter weight of the rat. The load bearing ball joints were replaced and the all bushings, steering and suspension parts were checked and a steering stabilizer was added. Still it hopped and shook like riding in a wash board road between 45-65mph and then smoothened out above 70mph. A different set of tires and wheels were tried and no change. The method used to lower the tire pressure was to run a line of powdered chalk across a level road and roll the tires over it. When the chalk was even across the tires that's the pressure I used. Amazingly, the front two did so at 22psi and the rear set did at 18psi. The ride on the first run was smooth all the way to 110mph. It has stayed smooth since. My guess is that the steel belts in the tires expanded at the problem speed and "bumped" the road with no give. By lowering the pressure the tire expands evenly. (?)

 

[Snake Farm]

Welcome aboard, I think you'll like it here.

 

[Old Iron]

Welcome aboard Nice ride

 

[jfg455]

welcome to the RRR

You could have a bent rear axle or something like that. Lowering the pressure in the tires will eventually just ruin your tires. they will run hot due to sidewall flex and eventually it will kill the tire. There is a reason for the pressure rating. You could also have a "frame Beaming" effect. Basically you will get to the resonate frequency of the suspension and frame at a certain speed. Due to the changed rake of the chassis and different loads than stock it will magnify the bounce right at the certain speed. Try putting the tire pressures back up to normal and drop 250- 300 lbs in the bed. If the shake goes away then that is what it is.

 

[rainman]

Perhaps. I'm open to suggestions. First the wheels were checked for out of round and balance. Same goes for the tires. The front wheel bearings and rotors were also checked. The shocks and springs in front were replaced based on the lighter weight of the rat. The load bearing ball joints were replaced and the all bushings, steering and suspension parts were checked and a steering stabilizer was added. Still it hopped and shook like riding in a wash board road between 45-65mph and then smoothened out above 70mph. A different set of tires and wheels were tried and no change. The method used to lower the tire pressure was to run a line of powdered chalk across a level road and roll the tires over it. When the chalk was even across the tires that's the pressure I used. Amazingly, the front two did so at 22psi and the rear set did at 18psi. The ride on the first run was smooth all the way to 110mph. It has stayed smooth since. My guess is that the steel belts in the tires expanded at the problem speed and "bumped" the road with no give. By lowering the pressure the tire expands evenly. (?)

Makes a lot of sense, I've seen tires do that before also!! It always scared me into thinking there must be a bad belt!! Only thing is, that wouldn't really explain why a different set of tires didn't change it!!! Anyway, that tire pressure is not that far from what I run on my truck!! I did the same just played with it to get the feel I wanted!!

 

[GJunktionMike]

Welcome to RRR