BlueXJ

From another site. Very useful info if you plan this swap.
Ford 8.8 rear axle information
8.8 FACTS, OPINIONS & HOW-TO'S (F.A.Q.)
________________________________________
I found some good specs and info on this earlier, so here ya go.

Here is a guide for the purchase and build-up of the Ford 8.8 rear axle and its compatibility and performance in a Wrangler or Cherokee.

There are many different variations of the Ford 8.8 axle. One of them is best suited for the use in a Jeep and that would be the Explorer (or Mountaineer) 31 spline 8.8. If you have found one off a Aerostar, Mustang, F-150 etc, you should really pass it up and look for a Explorer axle if you wish to retain a similar track width on your Wrangler. Trying to start your build-up with the wrong axle will be frustrating and expensive although you may have picked it up for cheap in the beginning.

Ford 8.8 assembly specs:
Cover bolt 28-38 ft.lbs.
Pinion bearing preload 16-29 in.lbs.
Pinion bearing preload 8-14 in.lbs (used)
Ring gear backlash .008-.015
Ring gear bolt to case 70-85 ft.lbs
Side bearing caps 70-85 ft.lbs.


Explorer 8.8 Measurements:
Weight (complete assembly w/ brakes etc.): 174 lb.
O.D. of tubes: 3.250".
Tube thickness: .250" (some are .188”!)
Ring gear diameter: 8.800".
Ring gear bolts: 7/16" dia. (qty. 10).
Pinion diameter/splines: 1.625 / 30.
Axle shaft/splines: 1.320 / 31.
Rotor thickness (where it mounts to axle is .250").
Overall width 59.625" (the F8.8 is .950" narrower then a TJ Dana 35).
(The F-150 8.8 is drum brake and width WMS to WMS is 65.5”.)
Hole diameter for ABS sensor in top of housing: .811".
Bolt size (U-joint flange to yoke) is: 12 x 1.75 x 30 mm
Centerline of housing to C/L of pinion difference is 3.875" toward the P/S.
Pinion offset: P/S to C/L of Pinion, 27-3/4" (no rotor on axle), D/S to C/L of Pinion, 31-5/8" (no rotor on axle). (this measurement is 2.5" more offset to the P/S then a TJ Dana 35).

Specs:
Code Capacity Ratio
43 Open 3200 3.08
41 Open 3200 3.27
42 Open 4.10
46 Open 3.73
45 Open 3200 3.55
D4 Limited Slip 3200 3.73
D2 Limited Slip 4.10
L73 Limited Slip 3.73
L - Limited Slip Differential
C - Conventional Differential

Thanks Chris Overacker for the specs and measurements! see his website link below.

How many splines are the axle shafts?
drivers side is 31 spline for 97 & up Mountaineer, 95 & up Explorer, 30-1/2 inch length - 5 X 4.5 inch lug pattern.

passenger side is 31 spline for 97 & up Mountaineer, 95 & up Explorer, 27-5/8 inch length - 5 X 4.5 inch lug pattern

Can I get 35 spline shafts? Yes, with a little searching I found 28 and 33 splines too. Remeber 8.8 axles are used on many different Ford rigs. Mustangs, Rangers, F150s, Aerostar etc... different axle lengths than the Explorer so if you are looking for aftermarket products make sure you are not looking at something for a Mustang that might not fit an Explorer. For the 35 spline stuff check with Mark Williams site. i dont have a link yet but i will soon.

Do I need a slip yoke eliminator? In my opinion, yes

Can I use my drive shaft that I bought for my SYE/Dana 35 set-up? Yes

Is the 8.8 narrower than a Dana 35? Yes but not enough to make a difference when running most aftermarket wheels.1.5" shorter or so. It doesn't matter unless you try running stock rims w/12.5 or wider tires.

Are the 8.8 shafts stronger than Dana 44 shafts? Yes, also the bearings, pinion and ring gear are also much larger.
Axle shaft Strength and output torque rating by Warn and 4 Wheeler

The axle shaft strength tested by Warn Ind:
F8.8= 6,500 (lb. ft.)
D44= 4,600-5,000 (lb. ft.)
D35C= 4,000-4,300 (lb. ft.)
-------------------------------
COT: Continuous output torque rating
MOT: Maximum output torque rating

(Numbers from January edition of Fourwheeler, page 60.)
Dana 35 rear axle COT: 870 MOT: 3480
Dana 44 rear axle COT: 1100 MOT: 4460
Ford 8.8 28spline COT: 1250 MOT: 4600
Ford 8.8 31spline COT: 1360 MOT: 5100
Dana60 semifloat COT: 1500 MOT: 5500]
(thanks joe and Chile99.)

Will I need that brake proportioning valve from a Rubicon? Maybe

Does the 8.8 offer more ground clearance over the Dana 35 and 44? Not under the differential but the bigger axle tubes lift the rig about 5/8 ".

Is there welding involved? Yes, but the new brackets you put on are much stronger than stock Dana’s. Not a good idea to re use your old Dana 35 brackets

Where do I get brackets?
4x4 Group Buy has Rubicon Express for $225+shipping.
Bob Supplee has Tera for $220 shipped.
DC4WD has Tera for $217 shipped.

Jeepers and Creepers
TeraFlex TMI-ABK-TR $250.99
M.O.R.E. Dana 35 brackets (sku:MORE98700) $290.00
Rubicon Express RE9969 TJ Axle Bracket Kit Rear $274.95
Mad4wd.com (sku:Mad-BKTK-TJ1) $275.00

Link to axle bracket placement on Stu Olson's site
The list above should get you headed in the right direction as far as brackets go. Look around and compare prices as the brackets can be found for $200.00 or less shipped sometimes. Keep this in mind when shopping for any item for your build-up,if you do, you will save a bundle.

Can I reuse my Dana 35 brackets? Yes, but it is not recommended. The stock Dana 35 brackets are sort of flimsy compared to the beefy aftermarket versions. Some of the brackets available are in fact for Dana 35 axles to replace the weak ones that come factory. Reusing the D-35 brackets is time consuming even if you have the right tools, not a good idea IMO

Should I weld the axle tubes to the cast housing? I would if it had been salvaged from a wrecked rig. If it is new on a crate don’t bother.


Will my stock sway bar work? Yes, with a minor modification to a passenger side pinion gusset.

Do all 8.8s come with a limited slip? No, read the tag on the housing or remove the cover. 3L73 = 3.73 gears witha "L"imited slip

Where is the gear break for lockers? There is no break. Same locker for 3.73 to 6.14

Do I need a notched cross pin? Yes for 4.56-6.14 to clear ring gear, or notch a gear tooth.

What year ford explorers do I look for as a donor for 31 spline and disc brakes? 1995 to 2001.

What is so great about 8.8? Parts are everywhere, as in axle shafts, covers, brake parts etc..

What's not so great about the 8.8? Weak stock carrier, replace with a carrier type locker like ARB or Detroit (not a lunch box type) this will cure the problem.

Spun axle tubes: Simply weld the tubes into the diff housing before they spin. You are welding to cast steel so now would be the time to ask for a professional's opinion. I have heard of guys tossing the works in a oven before welding, some just go at it cold. Both say their way is right.

Thin stock diff cover: Get some armor.

(my axle was new surplus and had not been in a collision, i know exactly where it has been from mile one and it is not welded. I don't believe my wheeling style will cause me problems, however i do keep a close eye on the plug welds.)

What kind of locker can I get?
$690.48 ARB SELECTABLE AIR LOCKER
$342.69 AUBURN GEAR - HIGH PERFORMANCE LIMITED-SLIP DIFFERENTIAL
$424.22 AUBURN GEAR - PRO SERIES LIMITED-SLIP DIFFERENTIAL
$535.72 DETROIT LOCKER
$229.59 E-Z LOCKER - FITS IN FACTORY NON-POSI CASE
$641.96 EATON - ELOCKER SELECTABLE LOCKING DIFFERENTIAL
$388.20 EATON - POSI LIMITED-SLIP DIFFERENTIAL
$209.04 FULL SPOOL - 31 SPLINE - STEEL
$118.46 MINI SPOOL - 31 SPLINE - C-CLIP COMPATIBLE - STEEL
$348.40 ORIGINAL STYLE POSI - COMPLETE
$261.52 POWERTRAX - LOCK-RIGHT LOCKER - FITS IN FACTORY NON-POSI CASE
$381.94 TRUTRAC LIMITED-SLIP
(prices will vary)

What is the bolt pattern? 5 on 4.5” just like stock TJ/YJ wheels.

Will my Jeep lug nuts fit the 8.8? In most cases, yes.

What do I do with the speed sensor? leave it in place.

Where to buy?
Car-part.com
www.ok4wd.com
wallysheata, Ariel Performance
www.alljeep.com
www.rockequipment.com
to name a few.

How much do they cost? Free to $1500.00 but you can find them new for around $500.00 in their stock form complete disc to disc.

What do I need for a swap into a tj?
Here are some things I usedOriginal Poster into a TJ)


-TeraFlex Bracket kit $200.00
-ARB $630.00
-U.S. Gears 4.56 $185.96
-Master install kit (Timken) $89.00
-Crane diff cover $190.00
-Napa brake line kit P/N 380528 $17.49 (x2)
-T-hose NAPA P/N 380889 $29.99
-ZJ E-brake cables (drivers and passenger side)
Mopar P/N 52008904 & 52008905 $23.00 NAPA P/N 95533 (right) 95322 (left). (not for YJs)
-Driveshaft adapter: Spicer 2-2-1379 $32.86
-Flange bolts Ford P/N N800594-S100 $1.29 (x4)
-'03 TJ Rubicon (w/disc) proportioning valve P/N 5083808AA $74.00
-3/16" hard brake line about 40" & 18" $5.00

HELPFUL SITES be sure to check these out:
Stu-Offroad
Dome & Detour
8.8 Swap
J.E. Towle / DPG Offroad
Chris Overacker / CODE 4x4
Stormtrooper
4x4 Wire Links
The Ranger Station Tech Library
The Ranger Station Tech Library 2

YJ & XJ STUFF:

From M.O.R.E.
-XJ Installation Kit P/N 98600 84-2001 XJ $165.00
-XJ E-Brake Cable Kit P/N EB3 Disc Brake F8.8 Only $118.00
-Special Yoke P/N 221379 F8.8 to 1310 U-Joint $40.00

From Dealership:
-Mopar spring perches $12.00
-Tabs for shock mounts $5.00
-ZJ ebrake cables from the dealer (for XJ install) $65.00
-Flange from spicer dealer $30 (have seen this go from $20-$50)





Specs:
Code Capacity Ratio
43 Open 3200 3.08
41 Open 3200 3.27
42 Open 4.10
46 Open 3.73
45 Open 3200 3.55
D4 Limited Slip 3200 3.73
D2 Limited Slip 4.10
L73 Limited Slip 3.73
L - Limited Slip Differential
C - Conventional Differential
Code Ratio
41 3.27
43 3.08
42 3.45
44 3.73
45 3.55
47 4.10
72 3.08C
74 3.45C
82 3.08C
84 3.45C
85 3.55C
86 3.73C
87 4.10C
89 (1992-1998) 4.10C
89 (1999-2001) 4.56C
91 3.27C
92 3.08C
95 3.55C
96 3.73C
97 4.10C
F4 3.45L
F5 3.55L
F6 3.73L
F7 4.10L
K6 4.10L
D2 3.45
D4 3.73L
D7 4.10
R5 3.55L
R6 3.73L
R7 4.10L

Some of the ones on the second list do not apply to the Explorer 8.8 (like the 4.56 one) as this list covers rangers too.
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