Air pressure will definetly affect ride. The "radial pull" that you were describing is actually referred to in the tire world as radial force variation. Basically think of the tire as a series of coil springs around the wheel. When one of the springs is stiffer than all of the others, you get a vibration once per revolution. Radial Force Variation (or RFV) can be corrected by "grinding" the tread in certain locations to eliminate the "high spots". Regarding air pressure, the more air the stiffer the spring (or tire in this case), resulting in a stiffer ride and more vibration if there is a RFV problem.

Regarding the vibration that you are feeling. If the vibration is coming from the tires and wheels, you may be able to narrow it down. If you are feeling a vibration at speed in your seat and the floorboards (similar feeling to flatspotted tires) than you have an RFV problem, specifically Radial First Harmonic (1 disturbance per revolution, lower frequency). If you have a vibration in the steering wheel (steering wheel shimmy) than the problem is more likely caused by balance.

Another thing that you can try is to change the positions of the tire / wheel assemblies on the vehicle, try to put the front tires on the rear axle and rear on the front, this may help you to determine which set is causing the vibration.

If it turns out to be tires, I would definetly be complaining to Interco.

 

Hm, the bouncing feeling seems to be coming from all over. I'll need hard evidence that it IS the tires before I can get Interco to replace them. I'll need a shop to analyze them and note on my bill that the tires are screwed, then I can get 4wheelparts.com to replace them under warranty.

Tom

 

Also, are you suggesting that I lower my tire pressure from 35psi so that I feel the vibration less? What pressure to you recommend?

Tom

 

Your truck requires a hub centric wheel. Using a standard lug centric wheel will almost certainly cause the problems your describing.

 

nobody make a hubcentric wheel for my truck. I've been investigating this forever. I called every single wheel manufacturer and asked them and the all tell me that the wheels for my truck are not hubcentric, except for my stock rims. I argued with all of them about how my stock rims are hubcentric, but they all continued to insist that the 5 on 135mm bolt patter ford rim does not have to be hubcentric and that they do not make a hubcentric spacer for it. I spoke with Mickey Thompson, American, Weld, Keystone, they all said the same thing.

I agree with you 100%, however nobody agree's with us.

Tom

 

Tom, you should ask about hubcentric wheels on the tire/wheel forum and see if anyone there has more insight but I'm willing to bet that's where your problem is. Newer Fords are not designed to center themselves via lug nuts, they do it with the hub. It might have felt fine before the lift because you just happened to get the wheel mounted relatively close to center. When you took them off to install the lift and remounted they got off-center. You could experiment with this by loosening lugnuts, re-tightening, and seeing if that changes the shake for better or worse.

I'm not an expert on wheels but everything I've read regarding the newer trucks says if you change rims you HAVE to use a hubcentric rim.

 

Actually Ivan I've already visited quite a few sites that sell hub centering rings. I just need to give them the ID and OD of the rings and they make them for you for 18 bucks.

This morning, I've called EVERY SINGLE rim manufacturer that I can think of, and NOBODY makes a hubcentric wheel for my truck, except for Weld. But they only make the one hubcentric wheel in the OEM size, which I cannot use with the larger tires because of the lack of proper backspacing.

Otherwise, I need to have the hub spacers made up.

I'm calling Mickey Thompson now to get the center bore measurement, then I'm going to order a set of rings. I think this will fix me up good.

Thanks everybody.

Tom

 

Sweet, hope that solves your problem. I can't imagine $60 rims are centering themselves too well.

Btw, nice looking truck!

 

My thoughts exactly Ivan!!!!!

Thanks for the compliment. It's still a work in progress. The M/T aluminum rims will dress it up some. Needs bigger tires also.

Dude, that Quiznos commercial give me the creeps man. I think the ad agency was on acid when they thought of that

Tom

 

It cracks me up. I started a thread in the General Forum about it and people were talking about how much they hated it so I had to make it an avatar for a while. Yeah, I'm a jackass.

 

Ivan,

Awsome intake manifold!!!! What's all that white stuff on the ground around your truck???? Packing foam or something?

 

Bwahaha! That there white stuff is the reason I bought a 4x4 in the first place. I drive in mud for fun, snow for work. I was supposed to be enjoying the sun in your neck of the woods in another month but ticket prices went up and I decided I'd rather spend the money on the truck . . . to combat more snow!

 

But not, as was stated, with the air pressures he is running. If your tire pressure is within spec and even between tires (as he stated it was) lowering the pressure will not alleviate his symptoms. His problems lie elsewhere.

 

yes, and I'm running into brick walls here with these hubcentric spacers.

There are dozens and dozens of websites that sell these spacers for cars and chevy trucks. However, none of these hub spacer manufactures make them for Fords.

They have suggested to me that the reason might be because (as Mickey Thompson stated) that the Fords do just fine Lugcentric and that a hub spacer is not needed if the wheel is of good quality.

However, they did say to try the new wheels WITHOUT the spacer and If I still had a problem, to buy a 1/4 inch thick sheet of nylon plastic and take it to a machine shop and have the spacers machined.

If anyone knows someone who can make them for me, the measurements are 84MM inner bore and 105.5MM outer bore.

Tom

 

Do you have a buddy with a truck that you can screw those rims/tires onto? Might be interesting to see if the same problem occured on another rig...