WELL,

I INSTALLED 315/70R/17 BF GOODRICH AT'S LAST WEEK ON STOCK 17" RIMS AND ALSO CRANKED THE TORSIAN BARS. CHECKED ALIGNMENT AFTERWARDS AND ALL IS GOOD THERE. HOWEVER WHEN DRIVING DOWN THE HIGHWAY ABOUT 65-85 MPH I AM FEELING ALLOT OF VIBRATION IN THE TRUCK. YOU CAN ACTUALLY SEE THE PASSENGER SEET VIBRATING AND FEEL IT IN THE FLOOR BOARD. SO, I WENT BACK TO BELL TIRE AND HAD THE TIRES REBALANCED AND STILL HAVE THE SAME PROBLEM. A WHILE AGO BEFORE I GOT NEW TIRES MY STOCK TIRES WERE WORN UNEVEN AND IF I ROTATED THEM MY TRUCK WOULD PULL TO ONE SIDE. BELL TIRE AND I BOTH NOTICED WHITH MY STOCK TIRES IT ALMOST LOOKED AS IF ALL 4 RIMS WERE SLITELY BENT. SO I TOOK THE TRUCK TO THE DEALER UNDER WARRENTY AND THEY CHECKED THE RIMS AND SAID THEY ARE JUST FINE AND THAT IT IS JUST THE UNEVENLY WORN TIRES MAKING IT LOOK LIKE THE RIM IS BENT. NOW WITH THE NEW TIRES ON THE RIM STILL SEEMS TO WOBBLE UP AND DOWN A LITTLE ON THE BALANCING MACHINE. SO, ARE THE 315'S TO BIG FOR STOCK RIMS?? ARE MY RIMS BENT?? SHOULD I TRADE THE TIRES BACK IN AND GET 285S??

 

ANYONE HAVE ANY SUGESTIONS?????

 

Just a guess, but I'd say it's a combo of the large tires and possibly too narrow of a rim. If they are the stock rims, then I think the 17" ones are 7.5" wide? I've seen where even 285's have a recommended wheel width of 8" minumum.

Other deal is that there's a lot of "mass" in those big meats. Larger, oversize tires have always been hard to balance pefectly and people just live with it or have to find really specialized places that can handle balancing large tires and even have them speed balanced.

Good Luck!

 

Hello mz6j3y,

I looked on BFG website and to see what the recommended rim widths are and this is the scope, your stock rims are 17/7.5's, you got the wrong tires. By the way I know you will get a lot of opinions on this but, I would never crank up my torsion bars you will throw the toe out which can cause a number of problems, including the one you described.

Link to specs.
http://www.bfgoodrichtires.com/asset...rain_ta_kd.pdf

BFG A/T
285/75-16 (7.5-9.0)
285/70-17 (7.5-9.0)
315/70-17 (8.5-10.0) *

 

I just put a 3" body lift and 35 12.5 16.5 on mine and have the same problem. My rims are 16.5 x 9.75. I was hoping it was balancing. I guess I'll start looking into alignment.

 

Thanks for the replies so far,

I did get my alignment checked after cranking the torsion bars and it was right on the money.

Any other suggestions?

 

Try installing a steering stabilizer, they cost about 45 bucks. I've heard that with big tires(35's and bigger) it's always a good and cheap mod.

 

Off the subject, but on the subject of steering stabalizer can you put that on any F series truck?? I thought it would just be something good to have.

 

There is nothing wrong with cranking your t-bar's as long as your front end is alighned properly. The toe in/out will have to be adjusted along with the all the other adjustment's which a good shop will do. If you take it to a bad shop or dealer they just have to make sure it's with in the spec's and really don't care about anything else. Lot's & lot's of t-bar's get adjusted without any problem's.

My guess would be to big of tire on to small of rim.

 

steering stabilizer are good for over-sized tires, they absorb alot of the vibration from the large tires. If you look at them, all it is a shock.

 

Well,

I am going to Bell Tire today to return the 315's and have 285's installed. I think the 7.5" wide stock rims are just not wide enough to handle the 315's. Thanks for the replies and i will let everyone know how the 285's work.

 

I have the 285's and they are great. Good luck!!!

 

try getting your tires road force balanced. If you do a search, you will get all kinds of info on road force balancing.

 

It is NOT the tire/rim combo. I have 35s on my stock rims and the truck rides great! In balanced these things with an old fashioned bubble balancer with the weights all on the inside edge. I have no shimmies, etc on this truck and I run MTs.

7.5" is plenty for a 35" tire!!!

I'd try another balancer first, I'd also check all your suspension parts, get a good alignment, etc.