Shared drivetrain components across platforms.

[bigdaddy2021]

Been wanting to gather some information together related to drivetrain similarities across late-model platforms. For simplicity I'm going to start at the front of our trucks and proceed to the back.

Why, you ask?

1. I want to dispense with anecdotal info around strength/durability of the 5th gen 4runner drivetrain.
2. I want to gather info that'll help myself or others with trail fixes, so that I know what will solve issues far from a parts store.
3. I'm an accomplished shade-tree mechanic and want to be as self-sufficient as possible.
4. I'm a nerdy car guy at heart (thanks dad) and digging up car info is my happy place.

 

[bigdaddy2021]

Front differential

I. Front differential

ASSERTION: The following models seem to all use the same 8" IFS clamshell front differential.

- 5th Gen 4runner(2010-20(21?)
- 4th Gen 4runner(2003-09)
- FJCruiser (2007-14)
- GX470 (2003-2009)
- GX460 (2009-?)
- Tacoma (2005-2022)

Earlier model year versions of these rigs look to have 7.5" front diff's and are probably not compatible, generally:

Research findings from various sites and sources:

ARB Air lockers
From ARB's website their RD111 and RD121 front 8" diff lockers are applicable to all these vehicles with the only split being related to ring gears.

2003-22 4runner FRONT
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.91 & UP -part #RD111
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.73 & DN -part # RD121

2005-22 Tacoma FRONT
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.91 & UP -part #RD111
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.73 & DN -part #RD121

2007-14 FJcruiser FRONT
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.91 & UP -part #RD111
8" DIA. RG, IFS, 53MM BEARING ID 33 (1.31") 30 3.73 & DN -part #RD121

ARB doesn't list the Lexus GX460 and GX470, but several stores sell kits for the a GX front locker:
ARB Front Air Locker 8″ 30 spline | Toyota Tacoma 2005, FJ 07+, 4Runner 03+, GX470, GX460 | Apache Offroad

This is the info they list, which references the same part numbers as the official ARB application guide:

8" Diameter RG IFS 53MM Bearing ID

#RD111 8" 30 Spline | 3.91 & Up Gear Ratios
#RD121 8" 30 Spline | 3.73 & Down Gear Ratios

Aftermarket CV axles
RCV aftermarket CV axles
StackPath

RCV sells a Gucci CV axle kit that covers these models:
- 2005 to present Toyota Tacoma 4x4
- 2007-2014 FJ Cruiser
- 2003 to present Toyota 4runner 4x4
- Lexus GX470 ('03-'09)
- Lexus GX460 ('10-'13)



OEM CV axles:

From CARiD

5th gen 4runner CV axle (L/R): 4343060061
4th gen 4runner CV axle (L/R): 4343060061
FJ Cruiser CV axle (L/R): 4343060061
GX470 CV axle (L/R) : 4343060061

GX460 CV axle (L/R): 4343060090
Looked this up - looks like dealers list this as fitting fifth gens, so this might be an alternate part number to try on ebay/RockAuto?

2005-up Tacoma CV axle (L/R): 4343004071

different part number for Tacoma's noted. Looked it up and looks like only Tacoma's are listed as correct applications. Would this be from a different outer hub assembly? Manual hubs?



Nitro gear sets

This 4.56 gearset is sold for the 8" IFS clamshell diff:
Nitro Gear & Axle Toyota 8" IFS Clamshell, 4.56, Nitro Reverse Thick R – Overland Garage

Applications:
2003 & Newer Toyota 4Runner
2003-2008 Lexus GX470
2009 & Newer Lexus GX460
2005 & Newer Toyota Tacoma
2007-2014 Toyota FJ Cruiser


Initial thoughts:
I'm interested to konw if these have platform-specific mounting bosses, and if CV's end up being more or less durable on a specific platform due to steering rack swivel distance/angle, available lift height, aftermarket upper/lower control arm geometry. I'd say that two stock or close to stock vehicles should have similar nominal strength and durability expectations, however. Also, parts compatibility across platforms for trail spares should be possible.

 

[bigdaddy2021]

Steering System

5th gen steering racks having catastrophic failures on a trail seems to be fairly rare, but I've heard several stories recently of steering rod ends (either inner, near the wheel), or outer (near the rack) failing, and also the rack itself starting to leak.

OEM Part numbers for the 5th gen 4runner, per CARID

Steering rack: 4420035094
Inner tie rod (near wheel) (require 2 per rack): 4550335070
Outer tie rod (near rack) (require 2 per rack) : 4504669245


OEM part numbers for FJ Cruiser, per CARID

Steering rack: 4420035103
Inner tie rod(near wheel) (require 2 per rack): 4550335070
Outer tie rod (near rack) (require 2 per rack): 4504669245

(tie rod part #'s are the same as a 5th gen 4runner, good to know)

OEM part numbers for Tacoma (05-up), per CARiD

Steering rack: 4425004021
Inner tie rod(near wheel) (require 2 per rack: 4504609340
Outer tie rod (near rack) (require 2 per rack) : 4550309480

OEM part numbers for the 4th gen/GX470

Steering rack: 4420035070
Inner tie rod(near wheel) (require 2 per rack: 4550339265
Outer tie rod (near rack) (require 2 per rack) :4504639505



Buuuut, looks like at least one company provides a replacement HD rack that covers these models:

Lexus GX470 2003-2009
Toyota 4Runner 2003-2009 (4th Gen)
Toyota 4Runner 2010-Present (5th Gen)
Toyota FJ Cruiser 2007-2014
Toyota Tacoma 2005-2015 (2nd Gen)
Toyota Tacoma 2016-Present (3rd Gen)

Toyota Steering Rack Upgrade / Tacoma 4Runner FJ Cruiser

Initial thoughts:
Looks like the rack assembly is fairly similar in all these models looking at CARiD with some differences possible. The aftermarket assembly seems to confirm this, since one part is offered that covers multiple models. Good to know that FJ cruisers use the same OEM part number as the 5th gen to widen the possibility of trail spares.

 

[bigdaddy2021]

Transmission/transfer case

Placeholder

 

[bigdaddy2021]

Rear Differential

Rear differential

Rigs with the 8.2" Differential (air locker info):

2010-22 4runner
REAR 8.25” DIA RG, 12-BOLT (SHIMMED) 33 (1.31”) 30 ALL RD193
2010-14 FJCruiser
REAR 8.25” DIA RG, 12-BOLT (SHIMMED) 33 (1.31”) 30 ALL RD193
2009-2021 GX460
REAR 8.25” DIA RG, 12-BOLT (SHIMMED) 33 (1.31”) 30 ALL RD193

Rigs with an 8" differential from ARB's site:

2003-2009 4runner
REAR 8" V6, 4WD, 50MM CARRIER BEARING 33 (1.31") 30 ALL RD132
2007-09 FJCruiser
REAR 8" DIA RG, 50MM CARRIER BEARING 33 (1.31") 30 ALL RD132
2016-22 Tacoma
REAR 8.0” DIA. RG, ALL AUTOS (EXCLUDING OE LOCKER EQUIPPED)
33 (1.31”) 30 ALL RD132
2003-2009 GX470
REAR 8" DIA RG, 50MM CARRIER BEARING 33 (1.31") 30 ALL RD132


Rigs with an 8.4" differential (slightly stronger than the 8", apparently) from ARB's site

1996-15 Tacoma
REAR 8.4" DIA. RG, 12 BOLT 33 (1.31") 30 ALL RD129


Initial thoughts:
I think this definitely helps explain some of the rear diff explosions I have seen on the trail or have seen in many video with early FJ's, 4th gen 4runners and GX470's.
Folks end up putting 35's on these rigs, and exceed the strength of their rear end with what I'd call fairly moderate/moderately-challenging wheeling.

 

[bigdaddy2021]

Tbd

Placeholder

 

[bigdaddy2021]

Also TBD

placeholder

 

[Jetboy]

Initial thoughts:
I'm interested to konw if these have platform-specific mounting bosses, and if CV's end up being more durable due to steering rack swivel distance/angle, available lift height, aftermarket upper/lower control arm geometry. I'd say that two stock or close to stock vehicles should have similar nominal strength and durability expectations, however. Also, parts compatibility across platforms for trail spares should be possible.

The Tacoma, GX, and 4Runner front differential assembly is interchangeable between any of them. With the caveat being that the gear ratios vary and the differential carrier is different depending on gear ratio. What varies is the spacing between the carrier bearings and the mounting flange. I have personally used both a Tacoma differential and a GX460 differential in a fifth gen 4Runner.

The passenger side extension tube with the automatic differential disconnect system does depend on model. Specifically the all-wheel drive 4Runner and GX460 versions do not have a disconnect. They have a straight tube. The Tacoma and forerunner with the ADD system have a intermediate shaft slide collar aka dog clutch mechanism along with an actuator. However, the assembly is easily removed and interchangeable on the clamshell housing. So you could take a clamshell housing from the GX, put a Tacoma or forerunner ADD assembly on and install it in a 4x4 version of a 4Runner. But you need to make sure the gearing is correct to match the rear.

For rear differentials there is less interchangeability. The rear differential on non-locking differential forerunners is interchangeable with a GX460 rear differential except they have different gear ratios and again a different carrier offset. The 4runner e-locker is on the interchangeable with other 4runner and some later year FJ Cruiser axles. There are no Tacoma rear differentials or axles that are interchangeable with the 4runner.

The front CV axles are interchangeable between GX460 and 5th gen 4Runner as well as the Tacomas that share the front 8" clamshell. And they are also interchangeable side to side. So only one trail spare is needed to fit either side.


Supposedly there are some minor differences in the needle bearing area and assembly on later years of the 8-in front clamshell. I do not know what the difference is are. I believe they remain interchangeable, but supposedly the needle bearing problem was somehow improved for the newer differentials. And I don't know what year that took place.

Hope that helps a little bit.

 

[02SE]

5th gen steering racks having catastrophic failures on a trail seems to be fairly rare, but I've heard several stories recently of steering rod ends (either inner, near the wheel), or outer (near the rack) failing, and also the rack itself starting to leak.

OEM Part numbers for the 5th gen 4runner, per CARID

Steering rack: 4420035094
Inner tie rod (near wheel) (require 2 per rack): 4550335070
Outer tie rod (near rack) (require 2 per rack) : 4504669245


OEM part numbers for FJ Cruiser, per CARID

Steering rack: 4420035103
Inner tie rod(near wheel) (require 2 per rack): 4550335070
Outer tie rod (near rack) (require 2 per rack): 4504669245

(tie rod part #'s are the same as a 5th gen 4runner, good to know)

OEM part numbers for Tacoma (05-up), per CARiD

Steering rack: 4425004021
Inner tie rod(near wheel) (require 2 per rack: 4504609340
Outer tie rod (near rack) (require 2 per rack) : 4550309480

OEM part numbers for the 4th gen/GX470

Steering rack: 4420035070
Inner tie rod(near wheel) (require 2 per rack: 4550339265
Outer tie rod (near rack) (require 2 per rack) :4504639505



Buuuut, looks like at least one company provides a replacement HD rack that covers these models:

Lexus GX470 2003-2009
Toyota 4Runner 2003-2009 (4th Gen)
Toyota 4Runner 2010-Present (5th Gen)
Toyota FJ Cruiser 2007-2014
Toyota Tacoma 2005-2015 (2nd Gen)
Toyota Tacoma 2016-Present (3rd Gen)

Toyota Steering Rack Upgrade / Tacoma 4Runner FJ Cruiser

Initial thoughts:
Looks like the rack assembly is fairly similar in all these models looking at CARiD with some differences possible. The aftermarket assembly seems to confirm this, since one part is offered that covers multiple models. Good to know that FJ cruisers use the same OEM part number as the 5th gen to widen the possibility of trail spares.

You have the inner and outer tie rods backwards. The Inner attaches to the steering rack or (near rack). The Outer attaches to the Inner, and is closest to the wheel, or (near wheel).

 

[bigdaddy2021]

You have the inner and outer tie rods backwards. The Inner attaches to the steering rack or (near rack). The Outer attaches to the Inner, and is closest to the wheel, or (near wheel).

I'm aware of this, thanks. This is exactly how the CARiD lists it (incorrectly) so i thought describing it's physical location, and also including CARiD's label would be helpful (for folks like you who know the difference).