Rear differential swap

[eric3]

Hey guys, first post.

I just got a 2011 XLT that's only RWD, and the axle code I have is 15 which I found means I have a 3.31 ratio open diff. I was wondering (and if this is a dumb question my apologies lol), would it be as simple as swapping the open diff for a limited slip or locker, or would I have to change the entire rear axle?

I haven't been able to find any limited slips diffs, but I found a Spartan locker that should fit. (http://completeoffroad.com/i-691294...Yf27j1frgv5WNquy97Wm-6pdBpOoES66gMaAjPr8P8HAQ)
Anyone have any experience or recommendations about this?

I drive on the pavement usually but I get in the mud plenty, and an open rear isn't exactly ideal of course!

 

[stamp11127]

Welcome to the site.

Have you ever set up a differential before? It is more than just a bolt in, you need the proper preload, clearances and mesh pattern.

 

[USMCBuckWild]

Its way less of a pain to swap the entire rear axle out for a junkyard unit if you are doing it yourself. You can swap it yourself but its not a simple job.

If you are going to pay someone, less work to have them swap the carrier out. This will also give you options to change gears to ones you want, different differentials and locker/limited slip units.

Just my $0.02

 

[eric3]

No I haven't set one up before, that's why I was wondering about all this. I would be paying someone to do it, as I don't have enough time or the space to do it myself, not to mention the experience! So USMC when you say "swap the carrier out", you mean the whole axle or just the differential?

 

[USMCBuckWild]

No I haven't set one up before, that's why I was wondering about all this. I would be paying someone to do it, as I don't have enough time or the space to do it myself, not to mention the experience! So USMC when you say "swap the carrier out", you mean the whole axle or just the differential?

Swapping the carrier is the very difficult. This involves dissasembling the entire rear differential (removing axles stubs, removing cover, removing the carrier, removing the bearing mounts, removing pinion gear and assembley) then applying the differential of your choice and gears of your choice (locker, limited slip, etc.) replacing the pinion bearings and seal then setting pinion preload, setting up the gears with appropriate gear lash. Can literally take 12 hours to set pinion preload and the lash on the gears, especially for inexperienced. Its all trial and error.

Or, you could swap out the entire rear end. Pull the axles, disconnect driveshaft, undo the 4 retention bolts and drop the old rear end out. Replacement is basically the reverse.

I have done it both ways and prefer the latter.

 

[eric3]

Swapping the carrier is the very difficult. This involves dissasembling the entire rear differential (removing axles stubs, removing cover, removing the carrier, removing the bearing mounts, removing pinion gear and assembley) then applying the differential of your choice and gears of your choice (locker, limited slip, etc.) replacing the pinion bearings and seal then setting pinion preload, setting up the gears with appropriate gear lash. Can literally take 12 hours to set pinion preload and the lash on the gears, especially for inexperienced. Its all trial and error.

Or, you could swap out the entire rear end. Pull the axles, disconnect driveshaft, undo the 4 retention bolts and drop the old rear end out. Replacement is basically the reverse.

I have done it both ways and prefer the latter.

So if I was to drop the whole rear end out to replace it, would I need to have a rear from another expedition or would an f150 rear end work? Again, my apologies if this is a dumb question!

 

[USMCBuckWild]

So if I was to drop the whole rear end out to replace it, would I need to have a rear from another expedition or would an f150 rear end work? Again, my apologies if this is a dumb question!

Another Expedition or a Navigator which is IRS (Independent Rear Suspension)

The F150 is a live axle (straight/full length axle) and would not fit without serious modification to the rear suspension.

 

[eric3]

Oh yeah good point, I forgot the F150 is a solid axle so obviously that wouldn't bolt on. The only issue with finding another rear end is that I haven't been able to find any donor vehicles that have a limited slip 9.75 rear, otherwise I would be getting it done this week probably.

 

[USMCBuckWild]

Someone said the new Navigators come with 4.10 LS rears. Also the SSV Expeditions are 3.73 LS according to those with mo knowledge than me.

If you aren't 4wd it makes life easy, you don't have to match gears for the front diff.

 

[Hawaiianbasshead]

Anyone know which rears are LS?