im looking to put Interco Super Swamper SSR's (35/14.5/16) on my 98 f150 im gonna put a 4" suspension lift on it will the 14.5 width tire fit? how much turning will i have?

 

I just put 35" tires and a 6" Fabtech suspension lift on my '98 F150 4x4. Worked out really good. For your turning; it might be close with just 4 inches lift.. don't know. (www.fabtechmotorsports.com)
What gears come in a '98 F150 4x4 rear end? (can't read my tag) --and what gear ratio would be best for 35" tires? Y'know?

Mark

 

Hi Mark and welcome to FTE

On the VIN tag on the door post is an axle code. If you post that here someone will decode it for you or you can do a search on here and you will find the code information.
The most common ratio is 3.55.
If it was my truck I'd go with 4.10's.
There are a few posts on here about good lift kits. If you're bored you might want to give your input on them

 

With a 6" suspension lift on my '98 Ford 4x4, I'm running 35" tires on 8x16" rims. I'm looking to find out what gears I have (from factory) in the rear end.
On the door post, the axle code is 19. Does that help?
Also, hey I'd recommend Fabtech and BDS Suspension kits (esp. the 6") to anyone with that style truckwho wants a little lift on it!

Thanks for your help,
~Mark

 

Code 19 — 3.55 non-limited slip.

 

i knew the 35" diameter would fit but i wasnt sure about the 14.5" width tire anyone know if that will fit?

 

The width of the 14.50 tire will require that you get wheels with less backspacing.

I do not know what the backspacing measurement is on the "stock" wheels but you can use the following example to help you figure out what new wheels will be required.

"If" the stock wheels have an offset of 5" and you can run a 10.50 wide tire on them without rubbing when turning then...

You would need a tire that had a 3" of offset to run a 14.5 wide tire.

You get this number via the following...

(14.50 - 10.50 = 4" 4" wider tire means that the inside half of the tire would be 2" wider and the outside half would be 2" wider. So you could run a wheel with 2" less back spacing to prevent rubbing and allow you to have the full turning radius)

Also, for a 14.50" wide tire you would need a 10" wide rim at a minimum and a 12" wide rim at a maximum.


Tires this wide will cause the truck's handleing to be different. The truck will tend to wander and follow grooves out on the road and also the steering will feel sluggish. This is because you now have 4 tires that have a total of 8" more contact patch with the road and have also increased the track width of the truck by 8" over stock.

Running tires this wide and needing to use wheels with less offset places more stress on the powersteering box, steering linkage, tie rods, ball joints and wheel bearings.

It's not that these components will all fail right away, it is just that they will all have to work harder to run those sized tires.

Not to mention what the brakes and the suspension are going to have to deal with from all of the increased weight and width of the tires.

If you are going with the tires based on looks and not performance, then living with the tradceoffs is up to you.

If you are going with larger tires to increase performance offroad, then you may want to consider tires that are narrower and will allow you to run wheels with more backspacing.

Usually, for general wheeling, a 12.50 wide tire with wheels that have a moderate amount of backspacing allows you to maintain your turning radius as much as possible and reduce the overall amount of stress to all of the related systems, (steering, suspension, etc) while realizing an increase in performance.

 

thanks a bunch. will i see a major diff in offroading by getting the 12.5 instead of the 14.5?

 

Depends what your offroading is.

If you spend a lot of time in sand dunes then a 14.50 tire would provide more floatation, but you would need a "lot" of extra horsepower to take full advantage of them.

For Rock Crawling, the 12.50 seems to be a much more poular choice.

For general woods/ trail running the 12.50 would be better. It will help get the truck thru narrower trails, require less backspacing for the rims, maintain a tighter turning radius, weigh less, put less stress on the steering and suspension and allow for an increase in performance.

For full competition mud bogging, the 14.50 would do as well if not better than a 12.50, but again, a serious addition to the engine in terms of horsepower would be needed.

If you plan to do mostly trails and woods, a 35x12.50 tire would work best for most conditions. Besides determining the correct backspacing for the rims, you would need to determine what your priorities are for onroad vs offroad performance and that will help you pick the rim width that best suits your needs.

An 8" rim for a 12.50 wide tire will allow you to run less air pressure in the tire (to increase offroad traction) and lessen the chance of the bead coming off the rim. The 12.50 wide tire will also help protect the 8" rim from getting dinged and scarred from the trail.

The 10" wide rim will allow the 12.50 wide tire to have a more even footprint and that will allow you to get more street miles out of the tire, but the 10" wide rim will lose the bead of the tire more easily when aired down offroad and the 10" wide rim will get dinged and scarred easier.

So the choice is up to you... Personally, I'd go for a rim that needed the least amount of backspacing to run the 12.50 wide tire and still prevent rubbing and use an 8" wide rim to get the best performance offroad and the logenst life out of the steering and suspension...