What is the largest tires you can stick under a '79 Bronco without a lift kit? I currently have 31's under it, and I think I could fit 33's. What do you guys think?

 

33x12.50x15 is about the max. Any more and you will rub in the turns.

 

I was just into a tire store tonight to get tires on my car, and I asked them the same question, and they didn't think 33's would fit. I know how much clearance is there, and I think they will fit, honestly.

 

33X12.50X15 only rub when making sharp turns other then that dont rub at all. When they do rub there only rubbing my radius arms.
Hope this helps

 

I had 33s on my 79. They fit fine, as long as you don't cycle the suspension hard. Then you'll run into the front tires grabbing the fenders and pulling the lips down. I had that problem on my pickup out tooling around in some rough terrain.

Zero issues out back.

 

Also, tire stores aren't going to be real savvy with fitment. If it's anything other than the stock size, they can't and won't guarantee any fitment. You have to research and determine what will fit, and tell them you want them put on. Now there are 4x4 shops and other specialty places that would have more insight and knowledge from dealing with this. But most tire stores have people in and out just needing new tires. Many times, they don't even pick the size. They just, at most, pick the style or price, and the shop puts either the same size on or the factory size in the tire the customer selects.

I had a shop tell me 33s wouldn't fit on my 77 pickup. I told the to put them on, because I knew they would. He said that once they were mounted, they were mine and he would not be responsible for any fitment issues, even if the truck was undriveable.

So anyway, to make a long post not so long, this is the right thing to do by researching for your answers.

If you plan to be off-road a lot and have a good probability of cycling the suspension very far, I'd hold off on 33s until you got some sort of lift or cut fenders with fender flares. I personally took the 33s off my 79 until I get my 4" lift kit. I'm just worried about the 33s looking too small with 4" of lift.

 

My uncle has a 79 (super nice dream truck). He has 33x12.50's. They are fine. When he turns real hard you can feel rubbing, but thats it. He recently put new coils and new leafs on it and it is the same, no problem unless you turn all the way. My advice, don't do donuts and you'll be fine. Also, he does zero off roading and almost zero on roading. I'm not sure there would be any off road issues.

 

Tire Size Chart

<TABLE border=5 itxtvisited="1"><TBODY itxtvisited="1"><TR itxtvisited="1"><TD itxtvisited="1">Years</TD><TD itxtvisited="1">Lift</TD><TD itxtvisited="1">Max Tire Size</TD></TR><TR itxtvisited="1"><TD itxtvisited="1">87-96</TD><TD itxtvisited="1">0"
2"
4"
6"</TD><TD itxtvisited="1">32"
33"
35"
36"</TD></TR><TR itxtvisited="1"><TD itxtvisited="1">80-86</TD><TD itxtvisited="1">0"
2"
3"</TD><TD itxtvisited="1">32"
33"
35"</TD></TR><TR itxtvisited="1"><TD itxtvisited="1">78-79</TD><TD itxtvisited="1">0"
4"</TD><TD itxtvisited="1">33"
35"</TD></TR></TBODY></TABLE>hope this helps

 

Cdy1, thanks for the chart. I'm plaining on getting new wheels in the future.
Kirk

 

Is there a chart somewhere for an '06 with factory 20" wheels?

 

You would do best to check with the guys in the F-150 forum for that information. Bronco production ceased in 1996.

Maximum tire diameter will be the same regardless of the wheel size. The chart and those numbers represent maximum nominal tire diameters. That said, the wheel diameter can grow as much as you want but the sidewalls have to get smaller as you go so you don't exceed the numbers shown in that chart. Just one note about the chart... 92-96 owners can use the 80-91 numbers as long as they shim the front bumper 2-3".

 

There are a couple of things you guys havent mentioned.

If the tire is only rubbing the radius arm, you need to adjust the stops. They are located on the back of the axle neer the ball joints. These should be adjusted out till the tire doesnt hit the arm. This does not increase your turning radius, it just makes the bolt stop you turn instead of your tire. This will not solve the tire rubbing the fender espeacially when cycling suspension.

The other thing that needs to be mentioned is backspacing, wheel spacers and wheel width. If you run wheels with less backspacing or wheel spacers or wider wheels, It will move the inner tire edge out. This can help with tire rub on the radius arm or inner fender parts. It has the added benifit of allowing you to run taller tires without increaseing turn radius.

I'm not a fan of wheel spacers and there arnt much choices for back spacing, but I like the wider wheels. I'm running 38" tires and my turn radius is the same as stock because I'm running 14" wide wheels.

But everything is a compremise. Because all three also make the outer edge move out, you will have more problems with rubbing the outer fender. The other issue going this route is increased ware on the ball joints due to the added laverage.

 

Personally would never run anything bigger than 36's on the D44 axle. Unsprung weight plays a factor in component wear and the kind of pressures that much unsprung weight applies to balljoints, bearings etc. just decreases the service life of these components. I hate replacing parts that frequently.

Adjusting steering knuckle stops will change turning radius... anything that reduces the rage of motion of the knuckles increases turning radius. The stops are set based on the use of stock tire sizes. (Stock tires sizes don't rub with the stops in their stock setting but would if the stops were run in further than they are). Adjusting the stops outward so that tires with a larger section width won't rub, reduces the range of motion of the knuckles. It won't keep your turning radius the same diameter as it was in stock form but it will save the shoulders of the tires that were rubbing the radius arms though.