Sport vs off-road axle

I know there are a billion threads on which is better but I have a specific type of question. Everyone always says the sport/sr5 rear axle is stronger than the off-road. What exactly does this mean? Can anyone provide real world examples of where the stronger axle would be better?

Also, does the sport model have any benefits in 4x4 compared to the sr5? Obviously the off-road would be superior to either stock.

 

The sport has an 8.4" ring gear and the locker TRD has an 8." I don't know any of the differences other than that people on TTORA claim that the 8.4" supports larger tires more readily than the 8.0". I don't know if that is 100% accurate or helps but that is my understanding.

 

It's not actually an 8.4" ring gear from what I under stand (though they do call it an 8.4). Last I knew both ring gears were 8" but they bolt up different and are not interchangeable.

So on 2nd gens, the factory TRD offroad ring and pinion is notorious for grenading (or at least it was in the early years, it seems to be much less common lately so maybe Toyota fixed something somewhere). I blew up mine with factory sized tires on pavement by just accelerating... It was replaced under an extended warranty (with all brand new OEM parts) and it started making some awful noise a few hundred miles later and I took it apart and found the new ring gear had some nicks in it. So I said to hell with it and got some 4.88's installed by East Coast Gear Supply and have been trouble free (even with crazy amounts of abuse) for 13,000 miles now.

Anyway, the sport third members have a couple of braces on the back side that help keep the ring gear from deflecting under high loads. The Offroad third does not have this. That is the bulk of where it is said to be stronger comes from and the fact that it is called an 8.4" while the Offroad is call an 8".

As for whether there is a noticeable difference in strength, I have yet to see anything that really proves it. From my story above, I think the OEM ring gears are flawed and not the third member itself. I have yet to see anybody with a TRD Offroad regeared with Nitro gears break. I have seen a person with Yukon gears grenade the ring gear, but Yukon doesn't have a good rep either... Basically I see no reason in letting third member strength be a deciding factor in your purchase. It should be a choice between factory locker or no locker/after market locker.

Also the Sport and the SR5 will be exactly the same offroad/in 4wd.

 

^^^ this is a good answer. I wonder if I could have a honest question with Toyota about this problem? I'd hate to buy something waiting on it to blow. And I have a heavy foot sometimes too so if normal driving could cause that problem that sucks.

 

I asked an amazingly similar question once, maybe it will help you out. http://www.tacomaworld.com/forum/2nd-gen-tacomas/286711-sport-vs-off-road-axles.html