8.8 Spline Count Question

[utherjorge]

Good morning! I just picked up a 2006 Ranger in decent shape for $900. The bed was toast (I replaced it already) and the rear axle was, too. The original axle was an R7, which had the limited slip. Let me tell you that when the case was opened...I've never seen such destruction. So, it had to go bye bye, and I swapped a "new" one in.

I grabbed one very close to me (like...2 miles) that I found on Car-Part.com. If you've ever seen how you make choices there, it was the bottom choice: 8,8", 4.10 gears and the 10" brakes, just like the original. Not an FX4. The original was a limited slip, or supposed to be, but we couldn't find anything on the one we yanked that showed it was in fact a L/S. With 160k miles, perhaps the original was long gone already. Dunno.

In any case...if it's a non-FX4 axle, it should be a 28 spline count, yes? I'm thinking of throwing a mechanical locker in there for the mild wheeling and offroad access I need to get to my camp.

danke danke and muchas gracias in advance for your help!

 

[sgtsandman]

The only axles that I know to have a different spline count for the Rangers is the FX4 models. So, if it is a non-FX4, it is a very safe bet it is a 28 spline axle. If there is any kind of ID tag still on the axle, verify that. If not, the only other way to verify is to count splines on the axle shafts or the carrier housing.

I would pull the cover to make sure they gave you the right axle anyway. I had a junk yard try to pull a fast one on me and gave me an axle they wanted to give me instead of the one I asked for. The gear ratio is stamped/molded/etched on the side of the ring gear.

 

[rubydist]

The 31 spline axles also have larger diameter axle tubes, so you can measure the tube.

 

[utherjorge]

The only axles that I know to have a different spline count for the Rangers is the FX4 models. So, if it is a non-FX4, it is a very safe bet it is a 28 spline axle. If there is any kind of ID tag still on the axle, verify that. If not, the only other way to verify is to count splines on the axle shafts or the carrier housing.

Definitely not an FX4. I feel comfortable that it's a 28...but the old one was supposed to have a L/S and I didn't see it. Maybe the Ford L/S is that different from the Gov-Bombs in GMs and Isuzus I've seen, though?

I would pull the cover to make sure they gave you the right axle anyway. I had a junk yard try to pull a fast one on me and gave me an axle they wanted to give me instead of the one I asked for. The gear ratio is stamped/model/etched on the side of the ring gear.

I was worried about this, too, but the axle cover they had was poop, so we had to swap covers anyway, and got a good look at the internals. Then, popped in 4x4 and drove it around to make sure the two ratios played nice nice, and they did. No binding, bucking, or whining.

The 31 spline axles also have larger diameter axle tubes, so you can measure the tube.

I did not know this. Are the axles that much more robust that they swapped that, too, for the FX4?

 

[RonD]

Good article here on the differences between 8.8" Ranger rear axles: https://www.therangerstation.com/tech/how-to-spot-a-ford-ranger-fx4-31-spline-8-8-inch-axle/

 

[sgtsandman]

I did not know this. Are the axles that much more robust that they swapped that, too, for the FX4?

The bearings are bigger. So they needed to increase the diameter of the tubes.

For what it’s worth, the 2010-2011 28 spline axles with disc brakes have bigger tubes as well. I’m not exactly sure why. I do know they did the switch to be able to install traction control.

 

[utherjorge]

The bearings are bigger. So they needed to increase the diameter of the tubes.

For what it’s worth, the 2010-2011 28 spline axles with disc brakes have bigger tubes as well. I’m not exactly sure why. I do know they did the switch to be able to install traction control.

Well, I did not know this...I might have wanted to snag one of those, but we'll see down the road. Gotta decide what mechanical locker to go for. Thank you!

 

[sgtsandman]

Well, I did not know this...I might have wanted to snag one of those, but we'll see down the road. Gotta decide what mechanical locker to go for. Thank you!

You have to be careful crossing years too far. Setups change every so often and might need the holes for the sensors your truck needs.

The 2010 - 2011 rear axles are very unique, which may be a big problem parts wise down the road. They were only used those two years and there is a number of things unique to them that no other Ford has that I know of.

The tone rings for the ABS are part of the axle shafts. The axle was modified to have the ABS sensors by each brake assembly. The brake rotors are unique. And the bearings are different.

 

[scotts90ranger]

Ford limited slip units are easy to spot with the diff cover off, the S spring between the spider gears is a dead giveaway, no spring is open, with spring is limited slip, the axle tag if it was still there is a good way to tell too, the second line will read 4 10 8 8 or 4L10 8 8 (or if 7.5" they read 7 5 instead of 8 8, don't remember if there's a decimal) .

But that doesn't matter for the most part unless you are going after a "lunchbox locker" as most normal lockers replace the carrier. Thu lunchbox units need the open carrier.

 

[Blmpkn]

Ford limited slip units are easy to spot with the diff cover off, the S spring between the spider gears is a dead giveaway, no spring is open, with spring is limited slip, the axle tag if it was still there is a good way to tell too, the second line will read 4 10 8 8 or 4L10 8 8 (or if 7.5" they read 7 5 instead of 8 8, don't remember if there's a decimal) .

But that doesn't matter for the most part unless you are going after a "lunchbox locker" as most normal lockers replace the carrier. Thu lunchbox units need the open carrier.

Lunchbox lockers can be installed without removing the carrier too correct? Thinking that's the route I'll go with my 96 if so.. at least for awhile.

 

[scotts90ranger]

Yep, pull diff cover, pull cross pin bolt, pull cross pin, pull tires, push in axle shafts to get C clips out then pull shafts out a few inches, pull spider gears then attempt to figure out how to shove the locker pieces in (they go in easier than come out...)

 

[00t444e]

It will be 28 spline, go with a Lock Right locker.