Fitting 40s tires on a M1008

[Enforced_Leo44]

Good evening everyone,

Just bought (or stupidly bought) a set of 40x13.5 R17 tires, Cooper STT PROs if that matters, to install on my M1008, which already has a slight lift, I think around 2", maybe 2.5" but no more on the front, and shackle flip in the back.

The rear has no problem, they fit nicely even if the spring flexes a lot, there's room to spare.

On the frontend though... that's a different story. The previous owners already cut the fenders a lot, I had 37x12.5 R17 on before and they fit nicely. The problem is that whoever cut the fenders, didn't cut them on the same spot longitudinally relative to the truck, like they "shifted" the fender about an inch forward on the right side relative to the left side. And because of that, the left side fits, while the right side tire doesn't, if I turn right, like not even one turn of the steering wheel, the tire rubs against the wheelwell. I'll attach pictures for context.

That rounds out to either cutting the fenders more, or lifting the front more. I'd rather do the latter since the front of the truck sits lower than the rear and I don't really dig the rake.

Would a 1" or 1.5" add-a-leaf/zero rate be enough to clear the wheels on the front?

 

[Barrman]

A lot depends on the off set of your wheels. Here is a video showing stock fenders, kind of cut fenders and then fenders cut even more.

I would suggest mounting the front wheels and tires. Then lifting each side of the front axle as far as you can and then try turning the wheel lock to lock left/right. Mark any place that is tight clearance and figure out how to make it better. Do not though just lift the axle a little, see it clears and think all will be well. You never know what kind of travel actual driving will cause is my point. Plan for the most travel.

 

[biscuitwhistler37]

What condition are the front leaf springs in? There was a post a while back where the truck was sitting raked like yours and new springs perked it right up. I'll try to find it and drop the link here.

 

[biscuitwhistler37]

Seems like this is turning into a build thread.

Would a new/stiffer steering stabilizer shock help the problem? That is entirely possible. I completely overlooked it when I was doing the suspension and bushing.

www.steelsoldiers.com

Stock tires, but still gained an inch and three quarters. Might be worth checking in to.

 

[CARC686]

I usually won't cut good sheet metal, but yours is already cut. In anticipation of logistics issues with living overseas, if I were in your shoes, I would just get out a tape measure, a roll of masking tape, an angle grinder with cutoff wheels, and your choice of corrosion preventive. There's no harm in making it symmetrical.

On another note, those tires weigh a ton. Reinforce your frame at the steering box if you haven't already.

 

[Enforced_Leo44]

I usually won't cut good sheet metal, but yours is already cut. In anticipation of logistics issues with living overseas, if I were in your shoes, I would just get out a tape measure, a roll of masking tape, an angle grinder with cutoff wheels, and your choice of corrosion preventive. There's no harm in making it symmetrical.

On another note, those tires weigh a ton. Reinforce your frame at the steering box if you haven't already.

Oh yeah of course, if I’m gonna cut, I’m gonna make it symmetrical without a doubt or at least try my best to do so.
For the steering box, the truck already has a ORD brace that goes from the steering box to the center of the crossover piece of the chassis, it should be tough enough. Plus this truck is never really gonna see any off road beyond some gravel roads

 

[dezertdemond]

I have 39" Toyo's on mine. I went with a 5" lift custom spring from Deaver, and also cut the fenders quite a bit. I don't have any rubbing issues no matter how much it flexes.

 

[Sharecropper]

I mounted new 11.00/20 NDT on my machine-shop-built 20" Firestone split rims. 44" tall, but only 12" wide. My truck is lifted 5", 4" of which is achieved with after-market springs and then ORD's 1" Zero-Rates with the front axle moved forward 1". Also moved the rear axle rearward 1" so that the axle was centered in the wheel well after installing ORD's shackle flip kit. Had to cut the front fenders, but they clear fine unless crossing a ditch on an angle. This will be rectified when I install the new fenders after the drivetrain replacement. I acquired a near-perfect set of original CUCV fenders and then had a professional body shop modify the new fenders so that there will be plenty of clearance. I also had that same body shop open-up the rear fenders at the same time.