1 ) when the term Ford 9" is used -- is that referring to the differential only or the entire axle setup?

2) If you used a 9 " rear, specifically a true Hi 9, would you also have to use a Hi- 9 front differential?

It's called a 9" because the ring gear is 9" in diameter. You can use any front you want, as long as it's the same gear as the rear. Ex: 4.10 rear, 4.09 front, 3.55 rear, 3.54 front, etc. Allowed 2% difference between front and rear gears.

It's called a 9" because the ring gear is 9" in diameter. You can use any front you want, as long as it's the same gear as the rear. Ex: 4.10 rear, 4.09 front, 3.55 rear, 3.54 front, etc. Allowed 2% difference between front and rear gears.


Sorry for the hijack, and I'm not cracking on you b454rat, but why do they say 2%. Is it .02 between gear combos(ie. 4.08/4.10). If it was truly 2%, wouldn't it be 4.10 * 0.02 (but I know that's the incorrect way)? I've always heard 2%, but I thought that it just meant .02 between combos. Again, not being a smartass(this time). And he's right, use whatever front you want to, just match the ratios.
Jordan

5 on 5.5 seems to be a very popular wheel bolt pattern. Is there any particular reason? I am thinking of a jeep cj 8 with 350 chevy motor, disk brakes, and 35" - 37" tires. What would be a good choice wheel bolt pattern and why?

I'd go with the most popular bolt pattern if you have a choice available. Better chance of being able to borrow a spare tire from someone should you be unfortunate enough to have two flats on one outing.
Bolt pattern is mostly dictated by what axles you're using (Ford 9s are usually 5x5.5").
Seems I see 5x5.5" the most often, followed by 5x4.5", then maybe 6x5.5".

One isn't really better than another on a wheeling rig (except maybe in the case of the 5x4.5", if the lugs aren't tightened properly, the studs can shear off from torque easier).

thanks, for bolt pattern info.

What is meant by floating axle ??

What is the simplest, strongest, most reliable method of engaging front wheels when in 4x4? (brands of hubs also wanted)

What are your options with reguard to front axle setup (mechanism allowing front wheels to turn -- "knuckles" I suppose). It seems that there are a few different basic designs. Again, what would be the simplest, most reliable, strongest for a beefed up rig? thanks in advance, I may have more Qs.

thanks, for bolt pattern info.

What is meant by floating axle ??

What is the simplest, strongest, most reliable method of engaging front wheels when in 4x4? (brands of hubs also wanted)

What are your options with reguard to front axle setup (mechanism allowing front wheels to turn -- "knuckles" I suppose). It seems that there are a few different basic designs. Again, what would be the simplest, most reliable, strongest for a beefed up rig? thanks in advance, I may have more Qs.


1. A full-floating axle is one that has wheel hubs that hold 2 wheel bearings each (just like your front axle). The axle shafts themselves carry no weight, they merely transmit torque. A semi-float axle doesn't have a wheel hub, just a flange for the drum and wheel to bolt to. There is only one bearing, and the weight of the vehicle rides on the shaft itself. Full-floaters are nice because:
-if you break a shaft, the wheel doesn't come off
-you can pull the shaft without screwing with the diff (no C-clips) or the bearings
-there are 2 bearings and they are beefier

2. Drive flanges or pucks are the simplest and strongest. As to hubs, OE Spicers are plenty strong but kind of a PITA to work. Warn Premiums are the only others I'd personally use.

3. Not sure what you're asking... You don't really have a choice for knuckles unless you want to swap the whole axle or have something custom made. The D60 has the strongest knuckles and joints among "normal" stuff (1-ton and under). D44 is pretty good for lighter rigs with smaller tires. All depends on what you have and what you're gonna do to it. These are both U-joint shafts (as opposed to CV style) if that is what you mean.

Positrac thanks

Without going custom, what rear ends have floating axles? Also, are all front axles floating?

Full floaters:
Truck version of the D60 rear, D70, D80, 10.5" GM 14-bolt (not to be confused with the 9.5" 14-bolt which is semi-float), Sterling 10.5" and 10.25" (Ford), and there are a few new full-float AAM axles under fairly new trucks but I don't really know anything about them. If I'm forgetting any, I'm sure somebody will fill in the gaps, but these are the most popular. If you see an axle with a hub sticking out of the center of the wheel a couple inches with bolts going into it, it's a full-floater. If the wheel bolts to a relatively flat flange on the axle shaft itself, it's a semi-floater.

All front drive axles must be full-float style by design, but some use a "unit bearing" that gives you a mostly flat flange with a nut in the middle of it that sorta looks like a semi-float design. Personally, I'd avoid them as the bearings are non-serviceable. When they wear out, you have to replace the whole assembly ($$$) as opposed to just replacing a couple bearings and races. Plus, they are generally not as big and durable as the old style servicable hub bearings. To my knowledge, all IFS trucks use this style, and some late model solid axles also came this way (such as the later Ford and Dodge D60 or D61 or whatever TF it's called).

It's called a 9" because the ring gear is 9" in diameter. You can use any front you want, as long as it's the same gear as the rear. Ex: 4.10 rear, 4.09 front, 3.55 rear, 3.54 front, etc. Allowed 2% difference between front and rear gears.


lots of people run 5.29 and 5.38 without problems which is a %diff of (5.38-5.29)/((5.38+5.29)/2)=.017 so 1.7%

Would it be possible to use a 9 inch rear diff with free floating axles. If so, how would you go about this?

I think Warn makes a full float kit, never checked on it. Could probly use the stuff off a full float 60 to use.