ratio
Freshman User
Joined: Jan 2005
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I don't know how to tell from the tag but you can get somebody to help you and count the number of turns of the wheel and the number of turns of the drive shaft at the same time. Then divide them and that gives you your ratio. The more turns you do (say 50 wheel turns instead of 20), the more accurate it is.
Elder User
Joined: Jul 2002
Posts: 520
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From: Wellington, CO
Or if it's already out of the truck you can pull the center section out and count ring teeth and divide by the # of pinion teeth. But the counting the turns should get you pretty darn close and you won't get quite as dirty.
Ron
Ron
Postmaster
Joined: Mar 2000
Posts: 3,730
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From: Waynesville, OH
Richard,
When you use the procedure yellowducman suggested, make sure you jack up one rear wheel of the truck only - leave the other one on the ground. I posted the incorrect formula for the axle ratio in an earlier thread
, but some of the other fellas straightened me out and gave me the right formula to use. If you don't have it handy, here it is.
Axle Ratio = 2 * Pinion Revolutions / Wheel Revolutions
When you use the procedure yellowducman suggested, make sure you jack up one rear wheel of the truck only - leave the other one on the ground. I posted the incorrect formula for the axle ratio in an earlier thread
, but some of the other fellas straightened me out and gave me the right formula to use. If you don't have it handy, here it is.Axle Ratio = 2 * Pinion Revolutions / Wheel Revolutions
Lead Driver
Joined: Apr 2002
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From: Littleton, New Hampshire
Originally Posted by richard jobe
i got the tag after searching fte i came up ratio of 2 47 it came out of 1981 f 150
with 5 on 41/2 wheels thanks for help life & limb houston freeways
richard jobe
with 5 on 41/2 wheels thanks for help life & limb houston freeways
richard jobe
Are you sure those aren't 5 on 5.5 wheels? I think the F-100 and F-150 trucks from 73-90 were 5 on 5.5 unless someone has re-drilled the bolt pattern or changed the axles...
Vern
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Lead Driver
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From: Saskatoon SK Canada
Vern, in the early eightys the light duty F-100 had 4 1/2" bolt circle wheels. You could also get them with the underbored 302, 255 cubic inch V-8.
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Lead Driver
Joined: Apr 2002
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From: Littleton, New Hampshire
Originally Posted by 51dueller
Vern, in the early eightys the light duty F-100 had 4 1/2" bolt circle wheels. You could also get them with the underbored 302, 255 cubic inch V-8.
I was unaware of that. Do you know what year trucks specifically the 5 on 4.5 inch bolt circle was available? Was this a nine inch? If so, it would seen that these rears would be great for our old trucks. It sure seems easier to use this rear end than replacing axles with car axles or re-drilling them to get a 4.5 inch bolt pattern. Wonder why haven't I heard about this before? Is there anything about this rear end that would make it a poor candidate for a rear end swap?
Vern
Lead Driver
Joined: Aug 2002
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From: Saskatoon SK Canada
I think it was a 9" (not sure) but they made only from 80-82 (83?). I don't think they made alot of them but it would still be the same width as the 73-79 axles. Remember they were used behind light powered engines and light payloads so it might not be strong enough.
Lead Driver
Joined: Apr 2002
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From: Littleton, New Hampshire
Originally Posted by 51dueller
I think it was a 9" (not sure) but they made only from 80-82 (83?). I don't think they made alot of them but it would still be the same width as the 73-79 axles. Remember they were used behind light powered engines and light payloads so it might not be strong enough.
Well, that's good information to know. Even if they were not 9 inch rear ends, they should hold up okay under a cruiser. I didn't even know they existed. All this time I thought the only bolt pattern for pickup trucks in those years was 5.5. It's just one more option available to convert to a more wheel friendly 5 on 4.5 bolt pattern. Thanks.
Vern
