8.75" diff?

[Stuckinthe80s]

Does anyone know how to identify a 8.75" rear? I did a bunch of google searching and the only thing I can find is info on the associated build codes on the door jam sticker.

I'm trying to figure out if this is one:

Its from a 2017 Tacoma and I know they started making them in 2016 but only on the TRD Offroad and Pro's.

 

[DaveInDenver]

The 2016+ Taco has an 8" option (the old BD20 was carried over, it's what's usually called the 8.4" axle) and two 8.75" options, the BD22A and DB22AN.

Externally they should look the same with the exception that the BD22AN has the e-locker harness.

How to tell one from an old 8" or the 1995-2015 8.75", no idea. I think the DB22 is the one with a big hump on top, like in this rendering.

This is maybe a better comparison.

The 8.4" (BD20) 1995+

BTW these are easy to spot out of the axle, they have the web trussing on the bearing clamps. They are called 8.4" but the ring gear is still 8" technically so Toyota refers to them as an 8".

The 8.75" (BD22) 2016+

For completeness.

Standard 8" 4 cylinder 79-95

V6/Turbo 8" 79-95

1995-2015 8" e-locker

 

[Stuckinthe80s]

I saw a TRD OR in the parking lot of the high school when I dropped my daughter off for volleyball practice and decided to take a pic of its rear axle and it had a similar sticker:

I’m probably on some watch list now for creepin on peoples vehicles but at least now I have something to compare to. I wish I could find a table to reference that decided it.

 

[Stuckinthe80s]

Looking at it some more and comparing against the pic you provided Dave, I think it is the 8.75. In the example you gave, there is a 45 degree cut in the casting near the pinion:

The axle in question has the same feature.

 

[DaveInDenver]

My question is why are you wondering? Are you planning to use one in a swap? I think you'd need to use the whole axle, not sure the thirds share a mounting pattern with anything else. OTOH the new e-locker is an improvement, similar as I understand to a Harrop.

 

[Stuckinthe80s]

My question is why are you wondering? Are you planning to use one in a swap? I think you'd need to use the whole axle, not sure the thirds share a mounting pattern with anything else. OTOH the new e-locker is an improvement, similar as I understand to a Harrop.

That’s fair. I’m working through how I want to setup the 4runner when I get going on it. I have an 80 series front axle that I am pretty sure will be used in the front and I'm trying to think through what to use in the rear. A 2nd and 3rd gen Taco rear, 65" WMS, is really close to the same width as the 80 front, 63.3" WMS, so I'm researching on how viable of an option that will be. The axle in the original post is on FB marketplace but is listed for way more than I'd pay for it. However, it got me thinking that one could pop up on there that might be better priced and I might be convinced to grab it.

My logic for even thinking about this:

1. The 80 front axle is more desirable to me than the mini because it's wider and stronger. Never mind the fact that I paid $150 for it and I can sell the mini front to put towards the rest of the project.
2. From what I can tell, the 8.75" rear is proving to be pretty stout for what it is. Mike Czajkowski has been running one on his 2016 Taco with 40's since he bought it and it's worked for him. Also, how many Taco's are running them with 35" tires and loaded down with every piece of overland gear known to man? I'm not finding a bunch of failures documented so I'm thinking it will be good on a thinned down 85 4runner running 35's, maybe 37's. It will be a good "phase 1" axle if I take care of it
3. The thought of tons seems appealing enough but I really don't feel like throwing down that kind of money on this just yet. I know that there's a strong possibility of me having to eat crow on this and realize the "buy once, cry once" theory holds true once again but we'll see. Besides, I'm not 100% locked in on this approach just yet, just thinking through it.

 

[DaveInDenver]

Well, to be fair, the regular V6/8" is fine, too. You usually have to reinforce the axle housing itself before the third is really a major problem. The issues with them are really the exposed locker actuator more than anything.

And it's my considered and generally suspect opinion that the best Tacoma axle prior to the BD22 was the plain Jane 8.4" with an Air Locker (thus strengthening the carrier itself).

In fact I might argue it's still better than the BD22 due to the truss. But OTOH the BD22 is apparently an adapted Hilux axle, so there's that.

 

[White Stripe]

Looks like a 8.75 to me. But I could be wrong. Just going off of memory.

 

[jps8460]

The truss makes it hard to add significant carrier bearing pre-load do to having to use shims. And having to get the truss in place in one stab. I’m sure the truss adds some strength, but not game changer levels of strength. The newer style 8.75 has more girth in all the right places. It’s pretty massive.

 

[DaveInDenver]

The girdle is one aspect. It must solve some problem Toyota thought needed solving. The 8.4 also have 12-bolt ring gears compared to 10 on the earlier 8"diff. Also the mounting studs are 10mm instead of 8mm and the pinion diameter is larger. So I guess it fits somewhere between the OG mini truck and what I suppose must be a lighter (relative) duty TGNA-F axle? I'd still ask "how strong is strong enough?" when measured against the number of trucks you'd have to find 8.4 donors (e.g. T100, Tundra, Sequoia, non-locked Tacoma).