All of above ^^
If you had to choose between the 2 on which one to do first, I would choose the FJ Case! The reason for that is because the t-case actuator is sometimes a more troublesome part then the front ADD Actuator. You just have to make sure your breather is hooked up to the front ADD or you'll be in for one hell of a clean up and repair job! I'll post pics of that later..
When you do your locker (if you plan to go bigger tiers like me) then you might as well re-gear while you're at it. To finalize the reliability factor for most of your drive line, there are many options for the front.
But the problem with the front is it will probably cost you more then doing the T-case swap if you do it yourself!
Posted from : http://home.4x4wire.com/erik/diffs/#front
'03+ 4runner, '04+ Tacoma, FJ Cruiser, '05-07 Tundra, ?? Sequoia: 8" IFS diff.
- Driver's side
- Clamshell housing
- 30 spline axles
- Carrier break: 3.91 and up, 3.73 and down.Posted
by RockKrawler of Allpro
"The front differential is an 8" mid pinion IFS that uses a gear not available through the common aftermarket. It is the same as the Non-US Toyota Prado front differential. The only current ratios available are 4.56 from Toyota OEM Japan and 4.88 from Mossiero in Italy. All Pro has 4.56 OEM Toyota Gears in stock, and 4.88 on the way in.
Front install kits are also not available from the common aftermarket. It uses the rear 86-95 V6 pinion bearings, but everything else is unique to the FJ/Prado. All Pro has gathered the parts together and can assemble a kit for you by special order, and have preassembled kits in the works. No solid spacers are available for the front differential
One last thing - there is a case break on the front differential. This means there are 2 different cases, or differential offsets: one that fits 3.73 and down, and the other that fits 3.91 and up. So if you have an Automatic FJ with 3.73 gears and want to go to a 3.91, 4.56 or 4.88 ratio, you need an open diff from a stick shift wth the factory 3.91, or you can change to an aftermarket diff like an ARB and get yourself some extra traction at the same time.
The rear on the other hand is just like your standard ring and pinion setup!
All 2wd and 4wd T100
's, '00-06 Tundra
's, and ?? Sequoia
's use a newer/stronger 8" 2-pinion diff. Tacoma
4x4's and Tacoma PreRunner
's that don't come with the electric locker
(aka "non-TRD), as well as V6 Tacoma 4x2
's also came with this diff.
This diff commonly and mistakenly
called an 8.4"
diff, possibly to imply its extra strength. The ring gear actually measures 8"
. The extra strength of this diff comes from the bearing cap/truss and large diameter pinion gear shaft.
LSD's available is the TRD/Kazuma clutch-type 3-pinion LSD, the OEM 4-pinion Tundra TRD LSD
, and the Detroit Trutrac.
Lockers available are the Powertrax "Lock-right," "No-Slip," ARB Air Locker
, Detroit Softlocker.This diff cannot be fitted to an older style 8" axle because it uses a larger diameter mounting bolt pattern and because more space inside the housing necessary to accommodate the large bearing cap. The different bolt pattern also makes it very impractical to swap in an electric locking Toyota diff (the whole mounting flange would have to be re-done using a special jig).
- Carrier bearing truss and newer housing adds significant strength over V6 and 4cyl diffs
- Uses V6 carrier bearings, larger pinion bearings
- Uses shims for backlash adjustment instead of threaded adjusters
- Twelve 12mm Ring gear bolts
- 10mm axle housing studs with 14mm nuts
- 30 splilne axles
- 30 spline pinion
* 4Runners do NOT use this diff at all.
Late-model 4Runners still use the V6 8" diff
** This diff is NOT swappable with V6, 4cyl, high-pinion, or electric locking diffs. This diff cannot be fitted to an older style 8" axle because it uses a larger diameter mounting bolt pattern and because more space inside the housing necessary to accommodate the large bearing cap.
So use the site above to get more info but the gearing and locking is where the money is if done right!!!