What axles do I probably have?

[ncbovid]

Can anyone post what axles and ratios were available in front and rear of the Bronco II?

I'm looking to do some repair work for a friend on the rear end of a 1990 Bronco II XLT with the 2.9. I know it's got a limited slip in the rear end. I figure we'll be able to find a junkyard Bronco deuce or a Ranger or maybe even a early Exploder with the same rear end and can just do a swap.

From what I've researched so far I figure that it might have a Dana 35 in the front and a 7.5" Ford in the rear with ratios of 3.45, 3.73 or 4.10. (i'm thinking it's the 3.73)

It doesn't have the tag on the cover, so please don't suggest that. I've told him to check the tag on the inside of the driver side door as well, but he's kind of an idiot and I'm not sure he'll be able to get me anything useful.

[12Ounce]

You can always jack up one rear wheel. Mark ( with "white-out") the driveshaft and raised wheel so that you can accurately count revolutions.

Rotate the driveshaft, counting the revs, until the rear wheel has made a full revolution. The number of turns on the drive shaft will be approx twice that of the ratio. For example, if it takes nearly 7, but not quite, turns of the shaft to turn the wheel once ... you have a 3.45.

Did I do that right ....?

[ncbovid]

Originally Posted by 12Ounce

You can always jack up one rear wheel. Mark ( with "white-out") the driveshaft and raised wheel so that you can accurately count revolutions.

Rotate the driveshaft, counting the revs, until the rear wheel has made a full revolution. The number of turns on the drive shaft will be approx twice that of the ratio. For example, if it takes nearly 7, but not quite, turns of the shaft to turn the wheel once ... you have a 3.45.

Did I do that right ....?

So you think I'll be able to tell between a 3.45 and a 3.73 if I did that... I suppose then going with your 2x logic there it would be under/over 7 revolutions. Makes sense I guess.

So then hopefully I won't have to worry about any ratios besides a 3.45, a 3.73 and a 4.10.

[12Ounce]

If you do the experiment carefully enough and are precise with your measurements ... you will be very close to "exact" ... no matter the ratio.

One thing to add to the process is a little constant drag on the rear wheel ... this will eliminate any effect of gear wear and gear "backlash".

[12Ounce]

OK, so I REALLY need a life! I woke up thinking about this problem this morning. (At least I was thinking about "rear ends" ... I know, bad joke!)

Anyways, I've told you wrong before: You should count the number of times the driveshaft must be rotated to rotate the single REAR WHEEL TWICE. For greater precision, you could always increase the number of rotations.

For example, lets say you have a 3.73 ... it would take 37.3 revolutions of the driveshaft to rotate the single rear wheel 20 times.

Man, I hope I've got this correct finally. Now I needs some black coffee!

[ncbovid]

Originally Posted by 12Ounce

OK, so I REALLY need a life! I woke up thinking about this problem this morning. (At least I was thinking about "rear ends" ... I know, bad joke!)

Anyways, I've told you wrong before: You should count the number of times the driveshaft must be rotated to rotate the single REAR WHEEL TWICE. For greater precision, you could always increase the number of rotations.

For example, lets say you have a 3.73 ... it would take 37.3 revolutions of the driveshaft to rotate the single rear wheel 20 times.

Man, I hope I've got this correct finally. Now I needs some black coffee!

Right on. I see where you're going with that.. anyway I haven't made it there to check on that. But I have been informed that it has the D4 code on the inside of the door panel. Now assuming that it's the original axle still, that would make it the 373.

We've found a couple of options for donor vehicles-

1986 B2 with a 3.73 ratio
1990 B2 with a 3.43 ratio

Wondering what the best solution would be. The thing of it is, price wise, we can get the front and rear off the '90 for about $250. The guy at the yard supposedly started it up and drove it around. The hubs on the front of our rig are shot to hell as well, so we could just do a swap on both the front and rear.

Off the '86 the guy wants $150. Not sure on driveshaft lengths, and dimensions of shackles and what not. But I think we could make it work.

Suggestions?