TF Rear Tire Clearance

[mdstitt]

Working on Spec'ing my rear axle for '56 step-side. Not sure how much clearance to leave between the tires and the inside fender lip.

I don't want it too close but I also don't want the tires to look like they are sucked in too far.

Any ideas on a rule of thumb? Anyone know what your clearance is for reference?

Open to suggestions.

Thanks.

[lazypineapple]

tire heighth is a factor. tires will flex on hard corners
rear suspension is another factor.. leaf or ? . leaf spring will flex on hard corners,
a tall tire with leaf spring i would say 1" would be safe

[mdstitt]

No Limit FatBar rear suspension.

Tires will be 295/45-R18 (28" Diameter). I expect them to tuck into the fenders a little.

[OrrieG]

Mine is a fleetside so I can't give you any measurements. You need to consider, tire size (you have selected that), wheel offset (will move tire sideways in the opening), opening size, and axle hub to hub distance. Once you select the tire and wheel, then a simple measurement (see sketch) will get you to an ideal axle width. compare to available axle options and you have an answer. If none work then you need to get one that is close and adjust the wheel backset and tire size.

[mdstitt]

Thanks, Orrie.

I am ordering a custom axle from Strange Engineering, so it can be any length I want. I am shooting for 4-1/2" backspacing on the 10" wheels. The only thing I can't decide on is how much clearance between the tire and fender. I thought 3/4" would be good, but I wanted to get other opinions.

I have an Excel spreadsheet made with actual measurements from my truck so I can punch in axle width, wheel backspace, etc. and it spits out the clearance between the tire to fender and tire to frame.

I see many people on here with 60" wide axles but that would force me into a minimum 5-3/4" backspace. That's too much, in my opinion because I want some depth to the back wheels.

[57halfton]

3/4 to an inch would be good but with that size tire on a ten inch wheel I take it you are going to tub the inside of the bed.
Gene

[mdstitt]

Yes, Mini-Tubs.

[57halfton]

I would say to get the tires and wheels you want then put them under your pickup with the outside clearance of 1 inch and the bed and bedsides cut for mini tubs then measure between the wheel mounting surfaces to get your overall rearend width. Give yourself about an inch and a half of tire clearance on the inside to the tubs. I have a Fat Bar setup in my 57 with air bags and have about an inch of inside tire clearance , and my tires will rub the bed sides a little like when I go into a driveway at an angle, dosen't hurt anything just rubs the paint off the raised ribs on the bed sides.
Gene

[G&R's57GMC]

Stock mounting flange to flange is 62"

The 9" I got from Currie via No Limit was spec'ed at 60".

I'm running 15x8" wheels with 4.25" back spacing and 235/70R15 BFG wide whites.

Body is not on yet so I hope they're not sucked in, If they are I'll move them to the front and go with 255/70R15's with a different offset.