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cj7 wheel set back
Can somebody give ne the absolute low-down on cj wheels and the proper set back? Seems like a straight forward question, but here is my story......Last year bought a 1976 cj5 to resell and glean parts off. One of the reasons I bought it was for the wheels(rims). Unfortunately, after I installed these "outlaw" wheels along with some 33x12.50 M/T MTZ tires I had two problems.
1) New tire/ wheel combo contacted front leaf springs while turning. About 1/2-1".
2) Worse was that the brake caliper actually gouged the wheel at the outer portion of the rim.
I measured the back spacing on my original M/T and it is about 3 5/8". The set back on the "new" outlaws (off the '76 cj5) was 4". I know that I have the large set of calipers on my cj7. I was always told that a wheel off a '76 cj should fit a '78 cj. What am I missing? I am now running wheel spacers, but will be looking for some new wheel soon. Is a 3 5/8" B.S. the only wheel that will fit? What about the inside clearance to avoid the brake caliber?
Tis has been a very anoying problem, but nobody has been able to give me some specific info to date. Are some of these issues brand specific?
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4" is about standard for a 15x10 wheel. I ran 4" backspaced Western Hurricanes on my 77 CJ7 for years.
It's not as much the backspacing of the wheel as it is the diameter of the tire that causes it to hit the spring. A 33" tire "swings" farther when it turns than a factory 29" tire because of the bigger diameter. (Think a longer lever).
The 76-79 "big brakes" are always a problem with thick aluminum wheels. When I had the Hurricanes put on my CJ, the tire shop ground the casting flash off the top of the calipers, and I had to do it again when I replaced the calipers later. They also had to be careful when placing stick on balance weights inside the wheel so that the caliper didn't scrape them off.
There is a stopper bolt on the back of each knuckle that you can adjust so the tire doesn't contact the spring, but it does decrease the turning radius. There's really nothing you can do about it except special offset wheels or spacers like you already have (or put 82-up widetrack axles under it).
Remember that the less backspacing a wheel has, the more leverage it has on the spindles and bearings. It can shorten the life of the bearings. The spacer does the same thing.
Bob
tufcj