Who wants a 2009+ FX4 E-locker in there 97-03? Here is what you need!
 

Okay so this research took a long time. You CAN put the 2009+ E-locker diff in the 97-03 9.75 rear end. Everything is the same except the axles. The spline counts are different. Most of us 97-03 owners know that there is no aftermarket true selectable "E" locker for our 9.75 diff. The only selectable locker is the ARB air locker. So you're wondering about the bearing sizes, bearing race sizes, and all that important stuff. Well I had a friend at my local ford parts department order everything except for the actual E locking diff to mic out all the bearing races, The I.D. and the O.D of the bearings them selves for the 09+ and 97-03 diffs. Everything measures up exactly for all 9.75 diffs. So to make this all work you have to get custom made axles and run a switch to your cab to lock and un-lock the diff. I looked through what seemed like a 900 page book of schematics to make sure the only thing that actuates the 09+ diffs is just a positive and a negative switch. The 09+ diff is not computer controlled. It's a simple two wire activated mechanism. Just run the wires out of your ABS tone ring sensor up to the cab and mount a switch for it and there you go. Hope this helps whoever wanted a true E-locker. It's a little on the high price as far as mods go but I don't like auto lockers and I don't feel like dealing with an air compressor and plumbing all the lines and finding a mounting location for the air compressor. I had an auto locker in my first 2002 and hated t because it would always lock on me when making sharp turns. If anyone has any questions please don't hesitate to ask!

DMD

great info!
not sure I get why the need for "custom axles" if everything is the same:confused: this probably where the high $$$ come into play:(

I like the general Idea though..turning on a diff lock when needed...& agreed the air locker is nice...lots to add for it

The custom axles are because the 97-03 9.75 axles are 31 spline. The 09+ are 34 spline. Everything else will work.

are you sure about that?

8.8 is 31. 9.75 is 34. 10.25 is 35

i always wondered if that locker would work on our trucks. but my 9.75 is 34 spline too.


how much is the locker from ford?

8.8 axles are 31 spline.

I will double check and post up the info...I could be wrong.

Str8t six - The axle from ford is expensive! Not too sure he exact price. I have a friend at a local ford dealer that gets me all my ford oem parts at cost.

well cool but custom axles....idk about that. Id hate to be off road and break an axle then have to wait for one to be made again rather than ordering one...and thats why I just went with a detroit locker. it does all the work for me. all i gotta do is hit the skinny pedal.

I had the detroit auto locker and was not really fan of it. The custom axles are going to be stronger than stock and I don't plan on jumping my truck or anything haha!

oh well if its not gonna leave pavement and only will use it for snow n stuff then ull be fine. prolly have crom-olly shafts and it will be very strong. i love my locker, hasnt let me down!

side note: I was talkin to my buddy with a 02 jeep wrangler sport. he got in a wreck a couple years ago, broke both axles but the tub and engine were fine so he just needed axles....he was able to upgrade to rubicon axles, arb front and rear air lockers. and with a highline kit and 3in lift springs hes runnin 37s. anyways he said movin up to chromlly axles were a slight improvment...but not much over factory axle (given the rubicon axles are stronger than the regular axles)

Trust me on these numbers. I have had more than enough rear diffs apart.

you should not need custom axles. Every 9.75" I have had apart is 34 spline.


I will also add that if you break an axle on a 9.75" rear diff you deserve it.

The axle spline count is the same. Thanks for helping me out. The difference might be the spline outside diameter. I dont remember but besides the bolt pattern for the wheels between the 97-03 and the 09+ I know there is a difference in the axles. I just can't remember.

I'd imagine it won't be long, and maybe even some availabe now...but you should be able to start picking these up in salvage yards.

Thats what I want to do. I leave for Guam in March for three years. I won't be doing this mod until I get back.