Axle Size on the 6th Gen 4Runner: Insights and Questions

[Trail4R]

As we dive deeper into the 6th Gen 4Runner and its TNGA-F platform, it’s becoming increasingly clear that the vehicle platforms across the TNGA-F family (Tacoma, Tundra, Land Cruiser, etc.) are not identical. In fact, they vary significantly depending on the trim and model.

I recently spoke with 74Weld, who shared some information from discussions with Toyota chassis engineers. They confirmed that the Tacoma alone features almost 18 different chassis variations, by factors like drivetrain (2WD vs. 4WD), bed size, and trim level (OR, Pro, Prerunner, etc.). This was surprising to hear but makes sense given Toyota's attention to detail in matching platforms intended for specific GVW, GVWR, and payload.

One takeaway was the variation in axle housing sizes among Tacoma models. Some are equipped with an 8.2" housing, while others feature the larger, more robust 9" axle housing. For those of us who wheel hard and push our vehicles to the limit, the 9.5" housing is clearly the choice for strength and durability. We all know what can happen with undersized axles and larger tires (shafts snap, R&P grenades, spider gear failure, hub failure, etc).

I would like to run 40" tires on the new 6G so we need the 9.5" housing to support the larger diameter and spline shafts on the 74W Portals.

The Tacoma TRD Off-Road features the 9.5" housing, but the big question is whether the 2025+ 4Runner TRD Off-Road trim will come with the same axle or if it will be limited to the TRD Pro and Trailhunter trims.

Does anyone have definitive info on this? Will the TRD Off-Road 4Runner get the larger 9" axle housing, or is it reserved exclusively for higher-tier trims like the TRD Pro and Trailhunter? Any insights or leads would be greatly appreciated!

@TRD JON - you have any insight here?

 

[TRD JON]

I'm not 100% sure yet on this one. But if it is like the Tacoma, then the Hybrid model should have a larger rear end. The only thing that makes me hesitant about this is the Land Cruiser. For some reason that got a smaller rear end and the GX got the larger one. The LC is a full-time 4x4 though, so maybe that is the reason. I'll hopefully get this answer next week.

 

[Trail4R]

I'm not 100% sure yet on this one. But if it is like the Tacoma, then the Hybrid model should have a larger rear end. The only thing that makes me hesitant about this is the Land Cruiser. For some reason that got a smaller rear end and the GX got the larger one. The LC is a full-time 4x4 though, so maybe that is the reason. I'll hopefully get this answer next week.

Yeah if you can ask the higher-ups at Toyota which models get the larger rear end that would be awesome. Thanks dude.

 

[Trail4R]

Just circling back here. So it sounds like the only models that will get the larger rear end are the hybrid models. So only the iFORCE Max models will get the 9.5" rear end.

TRD Off-Road i-FORCE MAX
TRD Off-Road Premium i-FORCE MAX
Limited i-FORCE MAX
Trailhunter (i-FORCE MAX is standard)
TRD Pro (i-FORCE MAX is standard)

I guess I'll be waiting for a hybrid then. lol