OK i need question answered from someone that knows the answer and has first hand experiance with this. I just bought some new wheels that are 16x8 with a +14 offset which is a bout a 5inch backspace and I am going to runa LT285/75/16's on them. Truck is a 1997 F150 4x4 ORP i need to knwo if my tire is going to hit the upper ball joint once the tire is mounted onto the wheel? My current wheel tire combo is 16x8 with about a 4-1/2 inch backsapce and the same tire and it apperas as thought it is clearing the balljoint by about 1-3/8 inch .
So is anyone running a 16x8 witha +14 offset and the LT285/75/16's? Can't wait to get my new wheels on they are sweet I will post a new picture of my truck since i have done many upgrades since the pic that is on page one in the owners gallery.

Richard D.

 

Richard OEM offset is 14mm. I am running 305s on the OEM wheels and I have no rubbing on the ball joints.

JMC

 

Ok but isnt the OEM wheel only 7.0 inches in width so the tire theoreticlly doesnt sit in as far and maybe you can help me with anotther question i have.I am going to need new tires in the near future and see that Pro Comp makes a LT305/70/16 is that tire going to fit on my truck since you say that is what you are running . Also what is the diff between the 285/75/16 and the 305/70/16 i have been told the 285 is 33inches but also that the 305 is 33 inches so whcih is which?The Pro Comp 305/70/16 tire says it is 33x12.50.16 and my BFG 285/75/16 are supose to be 33x11.00.16.

Thanks,
Richard D. Nice to hear from you by the way beena long time

 

Richard,

I am not sure about the ProComp but the BFGs are the same dis. The only difference is the section width. The 285s are 11.3 inches wide on an 8 inch rim and the 305s are 12.2 on a 9 inch. I have friends running 305s on 10 inch rims. I can ask them what offset that their wheels have. They do have rubbing on the front valance so a trim was needed.

JMC

 

Thanks i would appreciat knowing about that i am not concerned about the front valance i can alway trim that my major concern is that right now with the Centerline wheels i am currentl;y running with my 285/75's i have about 1-3/8 inch clearance from the upper ball joint . When i test fit my new 16x8 wheels that have roughly an inch more in positive offset i am worried that my tire once mounted to this new wheel is goign to hit the upper ball joint due to the fact that the new wheel sits back in further and that when i move up to the 305/70 it is only going to make that worse.

Richard D.

 

Richard,

I see your point. If you clear by 1 3/8 now with the 285s when you mount the new wheel your 285s will only clear by 3/8s. If you mount a wider tire you will rub. What wheel did you purchase? Is is hubcentric like the OEM or lugcentric?

JMC

 

It is a Cragar Tease16x8 with +14 offset Hubcentric It is a really sweet wheel. JMC what is the rim width of your stock wheels isnt it 7.0 inches?

 

Well i just got off the phone with the manufatcure of the wheel and all there applications guides show the F150 takes a +14 stock like you said however they cannot gaurantee that once i mount the 285 they will fit and once i do mount a tire I can no longer return the wheel sort of a catch 22 damed if you do damed if you don't. So i decide to call my local tire guy Americas Tire and talked with them about it there computers say i need the +14 also and thata 0 or Negative offset is not recomnede as it will cause damage to drivetrain componets and rubbing. They said the 285 will fit on the 8 inch wide wheel but that i need a 8.5 inch wheel to fit a 305 because the side wall will then bulge out to far when on the 8 inch wide wheel. So here i am stuck in confusion land once againF#$K

Richard D.

 

I would still like to hear from anyone who has the combo i have mentioned and am concerned about so here it is.I need someone who is Running a 16x8 wheel with a +14 offset and a 285/75/16 or 305/70/16 and running it on a 1997 thru current F150 4x4 with ORP. My concern is that once the tire is mounted it is going to hit the upper balljoint.

 

Richard,

Did you measure the backspaceing on your new rims? According to my calcs it should be 4.5512 in. 14mm is .5512 in.
An 8 inch rim has a center line (CL)of 4 inch. Add a + 14 mm offset to that and you add .5512 inches, so the back spacing is 4 in + .5512 or 4.5512 inches.
you say your 285s have 1 3/8 inch clearance from the ball joint then the new wheels should have the same clearance. So if you go to a 305 which is about 1 inch wider, then the clearance is ½ inch lesss or 7/8 inch.

JMC

 

Richard,

I just thought of something. Have you checked your 285s for signs of rubbing on the frame when the steering is cranked all the way to one side? If they don't rub measure the clearance.

JMC

 

Thanks for the info . As far as the 285's rubbing this is my second set of 285's and I have never had any sings of rubbing what so ever with the current wheels i am running which are Centerline 16x8 with a positive offset but it is less than the new wheels i have. Decided to just go ahead andcheck the lock to lock clearance on the frame and there seems to be roughly 3 inches dependong on what and where you measure so no issues there my main concern is the balljoint but it seems as though they should be fine according to The Wheel manufacture and Americas Tire. So we will see I should be getting a replacement wheel for one that was damaged cosmeticlly tomorrow then it will be off to the tire shop Tired of running around on the ugly black spoke spare i am using now.

Richard D.

 

Well I finallygot my question answered today after installing the wheels and tries on my truck .THEY CLEAR

There seems to be just about 1/4-3/8" less clearance than the previous wheel so all is good however I don't thinkl a 305/70/16 is going to clear so i guess I won't be able to upgrade to those when i need new tires. JMC thanks for the help .

Richard D.

 

Richard,

When you decide to get new tires ask them to trial mount a 305. If it fits, you ere laughing. If it doesn't, just have them put on the new 285s you choose.

JMC

 

Yep that's what they said they would do for me .
Thanks for all the help by the way,and I have anopther question maybe you can answer or at least direct me in the right direction.Do you know whee to locate replacement Braided stainless Steel Brake Lines? I am upgradeing my Rotors to Powerslots and HAWK brake pads and i would liek to get SSLines also. I tow a boat up and down some hilly areas and i tend to get alot of brake fade and it gets really bad come summer time when its 100 plus degrees outside.

Richard D.

P.S. I will post some pictures of my new wheels and my updated truck pics in my owners gallery once i get my film developed so you can see the wheels i got