Explorer ST/Timberline Part Swap

I Bleed Ford Blue · Dec 14, 2021

From that pic it appears to have the teeth of the ring gear cut directly into the differential carrier. Thus making gear changes virtually impossible.

Here is a thought, use a mustang IRS housing and bolt the explorer rear cover onto it. You would just have to fab something to support the front (pinion end) of the housing. Then you can use whatever diff and gearset you wish. But if you want to keep the AWD or intelligent 4wd, you either get the front gearset out of a hybrid explorer, they get 3.73's and there is a mustang gearset at 3.73 also, or have a custom set of gears cut at a 3.58 ratio.

Now all of this is moot if the mustang parts fit into the explorer housing.

https://turn5.scene7.com/is/image/Turn5/406490?wid=810&hei=608&op_usm=0.8,1,10,0

jrgoffin · Dec 14, 2021

There isn't going to be a practical way to fab up any other carrier to fit this chassis, especially from the Mustang. There is serious support on the front end of the Explorer housing. As I mentioned before, the most practical way to put a Torsen diff with the correct 3.58 gears in to an ST is to just buy the complete carrier for a Timberline.

I Bleed Ford Blue · Dec 14, 2021

I just did a quick search and there is a timberline sitting on the lot at a dealer here in the Cleveland area. The vin is 1FMSK8JHXNGA11264
I don't know if you can get any info from that at home on your PC or you have to go to a dealer parts counter.

From looking at the pic of the EX 8.8 and the mustang 8.8, it doesn't look like the rear covers are swappable. Oh well, it was worth a shot.

jrgoffin · Dec 14, 2021

I think the ‘22 models currently on dealer lots (if they are actually still there), won’t have VIN’s that even register in the Ford parts system yet. I’ve found some that were listed as ‘21 models (eBay as well), and those VIN’s should work. Still, some of the parts that are Timberline specific aren’t even in the system, but should be sometime soon as my local parts guy told me.

midnightSun · May 31, 2022

jrgoffin said:

Does anyone have a part number for the Timberline 3.58 carrier assembly?
I pull a trailer in the snow so this will help with the family loaded. Thanks !

Timberline cline · Nov 8, 2022

jrgoffin said:

The differential used is close to the Super 8.8 in the Mustang, and to the best of my knowledge, the Torsen uses the 34-spline shafts. For a swap in to an ST, it could be easy, especially if you have the entire carrier (would be nice if Ford Performance would offer that some day, so I’ll mention it to friends there). Either way, its 3.58 gear is an 8.8.

Adding to that, here are pictures of both the 8.1” and 8.8” carriers from the rear. It’s easy to see their differences, and obvious the Timberline is also an 8.8.

The 8.1:

View attachment 8932

The 8.8:
View attachment 8933

i took a picture of my 2022 ford explorer timberline differential it's has the 8.8.

vica153 · Oct 20, 2023

Part # for Timberline rear diff is M1MZ4000TB ? ~$2500 give or take. Has anyone tried this swap yet? The ST is easier to come by and comes with cooled seats among other things. Add a Torsen rear diff and STimberline badge??

mawhitlow · Nov 14, 2023

Has anyone counted splines on the 8.8 stub shafts? Curious if its same as the mustang. I am asking as I narrowing a mustang rear suspension for retro fit and like the idea of using explorer vs mustang setup.

UNBROKEN · Dec 13, 2023

Update for this thread....Lincoln Aviator PN L1MW4000HC is the same as the Timberline, 3:58 geared 8.8 Torsen. I picked up a low mile used one today for under 400 bucks.

TMac · Dec 13, 2023

UNBROKEN said:

IIRC, Platinum ST did this and posted about having some type of problem with axle fitment- before he ditched the whole thing and sold his truck. Any idea about whether that is a problem?

UNBROKEN · Dec 13, 2023

TMac said:

Don’t know why…the half shaft PN’s are the same.

I Bleed Ford Blue · Dec 13, 2023

Hey UNBROKEN, can you pop the rear cover and let us know how it is set up internally before you install it?

UNBROKEN · Dec 13, 2023

I Bleed Ford Blue said:

It’s a Torsen…it’s just like every other Torsen I’d imagine. lol

jrgoffin · Dec 13, 2023

UNBROKEN said:

Would be cool if it’s true, but that isn’t a part number, it’s an engineering number on the housing. It only means the case is the same. The Timberline carrier assembly part number is listed a few posts up and it only cross-references to the 2.3 model. If you look in through the axle shaft splines and see the worm gears, it will then be a nice discovery. Have been meaning to look in to this since I have a Torsen diff in my Cobra that rocks, but over $2,000 for a new Timberline carrier isn’t anything I care to flush cash on.

UNBROKEN · Dec 13, 2023

jrgoffin said:

Here’s the tag. 3.58L only matches the timberline. They posted that the L denotes, limited slip.
Already been verified by someone else but if that wound up being untrue, for some reason, obviously all posts would be retracted.

jrgoffin · Dec 13, 2023

There are several variations with the 3.58 gears using the 8.8“ differential. Again, that tag is an engineering number, not a part number. The part number for the ST/Aviator entire carrier is L1MZ-4000-D (to the best of my recollection), whereas it’s M1MZ-4000-TB for the Timberline. I looked pretty thoroughly at the Aviator in ‘20 before buying my ST and never noticed anything about the Torsen diff. Maybe you’ll discover something new here though.

UNBROKEN · Dec 13, 2023

jrgoffin said:

Well if you google L1MW4000HC the only thing it applies to is the Aviator rear diff.
If you compare the tags only the Aviator and Timberline share the 3.58L designation.
The guy that posted it builds ST body parts and owns a body shop. He has a Timberline diff and his tuner has an Aviator diff. He says they’re the same thing. I asked him again tonight to confirm again.

I Bleed Ford Blue · Dec 13, 2023

Having a 3.58L designation is a good sign. Ford typically uses the 'L' paired with numbers to designate the ratio and to indicate a limited slip type of differential. Back in the fox body/SN-95 era there was a stamped metal tag under one of the rear cover bolts and ford used to put the L in the middle. A 3L58 would mean a limited slip, whereas a 358 would be an open diff.

jrgoffin · Dec 13, 2023

Now search the S606B differential, which is on the tag. The same ENGINEERING number will come up for both the Aviator and ST. Same part numbers I already posted.

UNBROKEN · Dec 13, 2023

The worst thing that happens here is I got a good deal on a replacement diff that I need anyway. The guys said they verified…they have no reason to lie or make things up.

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