Axle Tech Info

[BLACK-FL4RUNNER]

I'm looking for the technical specs of our 5th gen 4Runners drivetrain.

Specifically,
What size front and rear r&p size, axle shaft thread count, strength, etc...
What is the maximum recommended size tire that can be run without sacrificing reliability?

Accurate information would be awesome, douchebag comments also appreciated.

Thanks

 

[marshal]

tits or GTFO

35" tires is really the biggest you can do with still having a reliable drivetrain, and even then its at a limit. any driveline questions can be mirrored by the FJ Cruiser, as it has an identical driveline.

also keep in mind that 35's are next to impossible to fit on the 4Runners without substantial modifications and a willingness to not get rid of your truck when you're done.

 

[BLACK-FL4RUNNER]

I've read in a couple places the front axles are 30 spline, but can't find the r&p size. Or the rear axle spline count... Or the rear r&p size.

Didn't know if all this was listed someplace, and I'm just an idiot and can't find it. lol

:noidea:

 

[Jetboy]

Front differential is an 8" clamshell with reverse cut R&P. IIRC I think all toyota 8" differentials that I'm aware of are 30 spline at the differential side. Mini trucks are 30 spline inner 27 spline outers stock. This would not apply to Tundra. I don't know for sure about newer Land Cruisers either. The 8" clamshell is weakest in revers and will blow up when you're in a hole and try to back out if you have too much tire and resistance. Also - don't try to pull someone out in reverse!

The rear is known as an 8.2, but uses an 8" ring gear. 8.2 distinguishes it from the more common 8" or Tacoma "8.4" that are all the same size ring gear at about 8". The 8.2 is substantially stronger in the 3rd member housing. Generally the pinion deflection is where failure happens. I'm not aware of an 8.2 failure yet. But It's probably been done. My guess is 35" tires are about the limit for strength under a 5,000lb SUV. Maybe 37's with a light foot? Also 30 spline.

The front is by far the weak link. The cv joints are not upgradable without spending enough that you could just do a SAS.

It's also very hard to fit 35s as has been mentioned. That's really the breakover point where you're going into serious custom mods - cutting out the IFS, re-locating the rear axle, etc. I'd love to build a monster, but I already have an FJ40 trail rig on 39's. So it's not going to be me.

 

[BLACK-FL4RUNNER]

So, it's looking like:

8" Front with 30 spline inners, weak outer cv joints
8" Rear with 30 spline axles

Excellent, thanks!

 

[bimrunner]

So, it's looking like:

8" Front with 30 spline inners, weak outer cv joints
8" Rear with 30 spline axles

Excellent, thanks!

Yep. Slightly stronger if you add ARB air lockers to them, but still do not reverse tug/pull. Best to winch others if you are from behind. Same is really true even with a stronger front diff. I still prefer to pull someone back with the winch rather than try a reverse recovery for many many reasons.

 

[BLACK-FL4RUNNER]

Are there any other options for lockers besides ARB?

I'm kicking around some thoughts about Lokka, I've had similar lunchbox styles in other vehicles. I think it would work well in the front, since the 4Runner has the axle disconnect.

Thoughts?

 

[bimrunner]

Are there any other options for lockers besides ARB?

I'm kicking around some thoughts about Lokka, I've had similar lunchbox styles in other vehicles. I think it would work well in the front, since the 4Runner has the axle disconnect.

Thoughts?

I don't think lokka offers one for our clamshell. They didn't when I installed mine 2 years ago. I've had very good results with my ARBs though. Key is to run the air lines well and carry some spare parts (I've yet to spring a leak though). Mine is also FT 4WD though... I drive a soccer mom vehicle.

 

[05Rrunner]

The front is 8" ring gear 30 spline / clamshell style reverse rotation
The rear is 8.2" ring gear 30 spline

 

[Jetboy]

Are there any other options for lockers besides ARB?

I'm kicking around some thoughts about Lokka, I've had similar lunchbox styles in other vehicles. I think it would work well in the front, since the 4Runner has the axle disconnect.

Thoughts?

I don't think I'd want an auto locker up front very badly. I suspect a Detroit Trutrac combined with ATRAC would be very close to a full locker in performance.

The best locker for the front IMO is the Harrop. https://www.harrop.com.au/shop/elocker-prado-amp-hilux-front keep in mind that's AUD. SO about $1200 USD. It's kinda $$, but no need for air lines and all the issues that they involve, no service intervals to replace leaky seals, that type of thing. Electronics have their own set of issues, but I'd generally prefer electric operation over vacuum/air pressure systems.

 

[BLACK-FL4RUNNER]

I would think a lunchbox style auto locker would work great in the front, since we have the passenger side axle disconnect. It would be virtually un-noticeable in 2wd, but lock up good in 4wd. I have had one in the front in a jeep before, but it didn't have an axle disconnect, and that thing was noisy on the street even in 2wd.

Just curious if there was any first hand experience with them.

So, is the rear an 8" R&P or an 8.2"?

 

[bimrunner]

I would think a lunchbox style auto locker would work great in the front, since we have the passenger side axle disconnect. It would be virtually un-noticeable in 2wd, but lock up good in 4wd. I have had one in the front in a jeep before, but it didn't have an axle disconnect, and that thing was noisy on the street even in 2wd.

Just curious if there was any first hand experience with them.

So, is the rear an 8" R&P or an 8.2"?

Rear is 8.2"

 

[STX4Runner]

...but no need for air lines and all the issues that they involve, no service intervals to replace leaky seals, that type of thing. Electronics have their own set of issues, but I'd generally prefer electric operation over vacuum/air pressure systems.

I agree. ARB's are great, but there's a reason windshield wipers, transfer cases and other systems are not vacuum actuated anymore.

 

[jwkilgore]

The best locker for the front IMO is the Harrop. https://www.harrop.com.au/shop/elocker-prado-amp-hilux-front keep in mind that's AUD. SO about $1200 USD. It's kinda $$, but no need for air lines and all the issues that they involve, no service intervals to replace leaky seals, that type of thing. Electronics have their own set of issues, but I'd generally prefer electric operation over vacuum/air pressure systems.

Lockers are on my long-term upgrade list, and I thought ARB was the only option. Do you know of a viable rear e-locker for a 2011 SR5? Is it feasible to install an OEM Trail rear locker on an SR5?

 

[Jeremy556]

Is it feasible to install an OEM Trail rear locker on an SR5?

Not unless you get an entire rear axle with the elocker for nearly free. You'll need the diff, elocker motor, and the axle tube, or do some cutting and welding on your axle tube to fit it.

 

[LandCruiser]

I'm still waiting for someone to do an SFA on a 5th gen, like the Ultimate FJC thing.

Slee, I'm looking in your direction.

I'm guessing new fenders will need to be fabbed.

Maybe we can crowdfund [MENTION=104049]marshal[/MENTION] 's truck to be brought back from the dead bigger and scarier.

 

[BlackWorksInc]

I'm still waiting for someone to do an SFA on a 5th gen, like the Ultimate FJC thing.

Slee, I'm looking in your direction.

I'm guessing new fenders will need to be fabbed.

Maybe we can crowdfund [MENTION=104049]marshal[/MENTION] 's truck to be brought back from the dead bigger and scarier.

Unimog Axles?

 

[bimrunner]

Unimog Axles?

[MENTION=104049]marshal[/MENTION] wants LT. I want portals!

 

[marshal]

I'm still waiting for someone to do an SFA on a 5th gen, like the Ultimate FJC thing.

Slee, I'm looking in your direction.

I'm guessing new fenders will need to be fabbed.

Maybe we can crowdfund [MENTION=104049]marshal[/MENTION] 's truck to be brought back from the dead bigger and scarier.

I'm so down. I need 5Gs

 

[Antman]

I'm so down. I need 5Gs

G
G
G
G
G

Now what?