I just bought a 2004 Ranger FX4 Offroad Not Level II from an insurance joint. The rear axle is bent a bit and wanted to know what the spine is. I get 28 when I do a part lookup and then I see that it is 31 if I go through forums. I just need to know what to order so I can slide that sucker out and put another back in.

 

All Rangers have a 28-spline rear axle, 7.5" or 8.8"

Only exception was Level II that had Torsen rear axle, not a Ford rear axle, this was not an "option" that could be ordered on other trims, only came on Level II

The 2010/11 models had rear disc brakes, but still 28-spline

Look on your driver door label, back edge of door, and get the AXLE code, then look here: https://www.therangerstation.com/tec...le_codes.shtml

That will tell you what ratio rear axle you have, it MUST MATCH front axle ratio, so a replacement must be same ratio, it can be L/S or OPEN, but MUST BE same ratio
L/S, limited slip is better

1993-2011 Ranger rear axle with be correct width for your 2004 and will just bolt on, best to use new u-bolts
1993-2009 with be direct fit for brakes
2010/11 would need some brake cable and line changes for the disc brakes

 

Yeah this is an FX4 with a R7 axle code. I ordered one online and Ford gave me a part number that was 31 spline but I find online that all of them were 31 spline and other places that all except a few is 28 spline. Nothing consistent.

 

Ill let it get here and tell you officially what I found.

 

Only Explorers had 31-spline, and the axle's leaf spring perches are in the wrong place for Rangers, also larger axle tube, 3.5", Rangers had 3"

R7 is a 8.8", 28-spline, 4.10 ratio with limited slip, this would be stock axle for FX4 Off-Road

My 4x4 has R6, 8.8", 28-spilne, 3.73 with limited slip


And just a heads up, the Torsen rear axle used R8 from 2002-2011 on Level IIs, R8 is also listed as 8.8", 28-spline, 4.56 ratio L/S, on earlier models although I have never run across one

 

Thanks Ron - Is there a book or something of that nature that has cross references for many of the part numbers?

 

No, not really, not sure you can get Ford dealer parts books, and not sure rear axle would have a "part number" per say, it would be a "build number" on a metal tag on an axle bolt

Like this one: https://www.mre-books.com/images/image35.gif

Or this one: https://www.ford-trucks.com/forums/a...1&d=1392559275

More info here: https://www.therangerstation.com/tec...er-rear-axles/

 

I try not to be too picky but I am pretty sure Torsen just makes the differential and not the entire axle. So, it should be a Ford axle with a Torsen differential not a Torsen axle. I know it is easier to just call it a Torsen axle but my brain gets twisted when I see technical information that is not quite right.

 

"The 2003-up FX4 (non-Level II) is essentially the same as the 1998-2002 Off-Road except that a regular Ford limited-slip in a regular 8.8-inch was included.

The Ford Ranger 28-spline 8.8-Inch axle tube is 3.00 inches in diameter.

The Ford Ranger FX4 31-spline 8.8-Inch axle tube is 3.25 inches in diameter."


This is where the confusion was - the new axle is due here in a few days - first I get a chance at a good non-rainy warm day I'll put it in.

 

I was under the impression that the 2002 Off Road had the 31 spine axle also, but I didn't know the '04 up FX4 didn't have the 31 spline axles.

I just call them the FX4 axles, the rear axle in my EDGE is a 31 spline FX4, large tube, Heavy duty... LoL, in the Mustang similar axles handle a lot of HP.

To clarify, the '03 EDGE didn't come with an 31 spline axle, I got it from and FX4, LvL II, I'm guessing '03.

admyank,
The best way these days is the Explorer, (Year ???), find one that already has Disc Brakes, and they usually have a posi of some sort.
You will need to switch the Spring Mounting Perches to the top of the axle or get a swap kit, but you end up with Discs, if the Ex had them, a posi, and you get a couple of inches in width.

 

2002 was first year for Ranger FX4 model and that came with Torsen rear axle, then in 2003 and up Ford added FX4 Level II model, Level II came with Torsen, 2003 and up FX4 off-road didn't

Yes it is a Ford 8.8" case, with Torsen gears inside, not sure if they are Explorer 31-spline axles, but these rear axle cases were same diameter as Explorer axle tubes, 3.5", Explorer axles were 1/2" wider on each side
These were all 4.10 ratio

Just looking at some brochures
2007 was the last year of the Level II model
2008-2011 has Off-road model only and had Torsen available, but as a pay extra option

 

The Explorer Axles are 2 or 3" wider than the Ranger and would give you a little better stability, and the Spring Perches are on the bottom and the Ranger's are on the top.
If you are lowering the Truck it will give you some drop, but it you want the standard Ranger mounting location you will need to swap the existing spring perches or there is a kit the add a top Spring perch and bolting a top perch in place.
The kit, although is should work, is IMHO, not as good as cutting off the lower perch and welding on a top perch, maybe new shock mounts will be needed.

All in all, if you get the one with Disc Brakes, and a posi, you are already ahead of the game. The extra width and the 31 spline axles are a bonus.

Find a good Explorer axles, some come with 4.10, while it is out of the vehicle and you are having the Spring Perches swapped over, have the gears in stalled you want to go to or to match the front, also, get a good rebuilding kit, and a good rewear kit, for the Ex Axle, it will paid for itself in the future.

Good Luck.

 

Yes, I can confirm the 02 FX4 Off-Road is the same thing as the later FX4 Level II with the Torsen differential and all the other stuff that goes with the Level II, including the manual shift transfer case with manual transmission that was in the 03 Level II.

 

Did the 2002's have the tow hooks fore and aft, and the 3 slid plates?

 

I know the 2004 FX4 has tow hooks and skid plates - but no tow hooks on the rear. The axle I ordered is in - after a trip to the junkyard tomorrow for two parts - I will be ready to say if the 28 spline works.

 

Just wouldn't be a thread without a dumb question from me.
Is the FRONT DIFF of my '05 FX4 Limited Slip?

And how 'bout those capacities! 3.2 pt. front, 5.3 pt. rear. = 8.5 total. Time to wait for a sale on synthetic. No gallons except for conventional.

 

Can't say on the amount of Gear Oil needed, check you manuals, should have something.

Most manufacturers were not using a front Limited Slip Differential, safety reasons were mentioned.

I have never heard of a Ford 4x with a front limited slip diff... !

There are products out there for you to install, liability on you !

Ltr

 

No, 4x4s never came with L/S front axles, not even an option, although it is an upgrade thats available

You will have a Dana 35 SLA axle on the front of a 2005 Ranger 4x4

 

Yes, the 02 FX4 had the stainless steel tow hooks in the front and if it did not come with a receiver for towing it, had one black tow hook in the rear. It also had the skid plates. It was basically the same as the 03 FX4 LII. There are a couple exceptions. In 03 the seats had two different solid color inserts available (red or blue, I believe). The 02 had what I call "cracked ice" inserts that were black and white. Some people don't like the 02 FX4 seats, I do. The 02 gage cluster has a black background while the 03 has a silver background, but that was more of a model year thing. One thing I found out when I got side swiped and the FX4 decal had to be replaced, the 02 decal is not the same as the 03+ FX4 decals. I ended up using the later FX4 Off Road decal because the 02 decal is no longer available. Since they can't be seen side by side, no one can tell he difference without me pointing it out. I don't even notice it anymore. I am sure there are other differences that are not related to the FX4 LII offerings.