E-locker Rear Diff into non-E-locker Rear Axle

My stock rear diff/third member in a 2004 Tacoma I recently purchased is on its last legs, and I've had a lot of trouble finding an exact replacement. The code in the door jamb reads B07A, which according to this thread tells me it's an 8" ring gear with 4.30 gearing.

I found a good-looking replacement third member which was stated to also have an 8" ring gear and 4.30 gearing, and I'm wondering if this will fit my current rear axle. I believe it was pulled from an '02 4runner. If yes, would it be relatively simple to hook this up without wiring up the e-locker?

 

8” elock third will not fit a 8.4” housing even though both uses an 8” ring if I’m understanding your question correctly. If you swap the entire axle (drum to drum), you’ll need perch etc since it’s from a 4R

Tacoma area 8” elock or 8.4” open
4R are 8” elock or 8” open

 

like 02hilux says, the 8” elocker does not fit the Tacoma (8.4) open housing.

you need the entire 8” elocker housing so you may want to pass and wait to buy a complete elocker Taco axle that is ready to bolt in.

if you have basic fab skills you can cut all the brackets off the 4runner axle and weld on leaf perches. That is actually what I’m running. 4runner elock housings are common and cheaper

 

I see, so the housings are sized differently even with the same size ring gear. I'll have to keep hunting then. Thanks!

 

Housings are sized the same. The only difference is the bolt pattern. You can put an E locked diff onto a non E locked housing but you'll have to drill holes open and weld holes shut.

 

you can do that to put an 8” elocker in the 8” non elock housing, afaik you cannot do that for the 8.4 housing. i would be interested in seeing it done lol

 

There's no such thing as an 8.4" ring gear, there's only 8". There's no reason why a locked diff wouldn't fit in a non locked axle other than the bolt pattern.

Not sure where the "8.4"" thing started, but it's been proven on many threads across the interwebs that we don't have an 8.4" ring gear.


I did hella research when I was going to attempt it, but I decided the work required is not worth it. So I went with an Eaton E locker and moved on.

 

the “8.4” ring gear is indeed 8” in diameter, but the third member housing and contents, including ring, pinion, carrier, and spiders, are all different from the regular Toy 8”

 

Yes, they're not the same, but the locked diff will fit into a non locked housing.

 

I suppose my next question is where would be the best place to look for a replacement third member? On mine the housing has rusted out and leaks oil, and over the years has slowly been wearing the internals down. I think it seems to me mounting the elocker diff into my axle is not worth the work, and I'd like to avoid buying a whole rear axle if I could.

Anyone have any recommendations on where to look? I'm not having any luck with nearby junkyards or eBay.

Edit: location in southeast Ohio

 

Posting your location will help. Or posting a wtb ad in your regional section

No luck on eBay? Really

 

Not trying to stir the pot, just posting for clarification since I've seen this information get mis-interpreted in the past.

Prior to the Tacoma there was the Toyota 8" axle.
Then there was the 8" e-locker axle.
Then there was the 8.4" axle. (8.4" was used to differentiate from the Toyota 8" axle, even though the ring gear is 8")

There are 3 axles in this discussion, but a lot of times people don't realize this when trying to say that the e-locker 3rd member can fit into a non e-locker axle if the axle mounting surface is modified. This mostly comes from people doing this to the pre-Tacoma 8" axle, not the Tacoma 8.4" axle.

@Nano909 I remember back in the days of TTORA there was a member that went into depth trying to figure out how to put the e-locker third member into a Tacoma 8.4" axle housing, but was not successful. Do you have any evidence of anyone successfully doing that? I'm not saying that its not possible, I just don't think anyone ever did it because it's much easier to just swap the whole axle. People did it on the pre-Tacoma axles because they were narrower and matched the front width on the pickup without having to go with a wider axle.

 

Looking past all the nuance of the 8" vs 8.4" naming convention: If your 1st gen Tacoma doesn't have an e-locker, then the best donor from which to get a replacement 3rd member is another 1st gen Tacoma without an e-locker (aka 8.4"). E-locker Tacoma (8") thirds won't fit. Pre-tacoma pickup/4Runner thirds won't fit. Third gen 4Runner thirds won't fit, as they all use the e-locker housing design (8") even when they aren't locking. Newer Tacoma/4Runner thirds won't fit.

T-100 and 1st gen Tundras and Sequoias should fit but I don't think any of those vehicles ever came with 4.30 gears. You might find 4.10 in a Tundra or Sequoia there, but many were 3.9something to pair with the big V8s.

Getting more specific, 4.30 gears came in 2000+ Tacomas with the 3RZ/2.7L engine paired to a manual transmission. There's a ton of variation in spec so you might find 4.30 elsewhere or you might find trucks that match that description but don't have 4.30--but from my research/experience, that's the magic combo you're looking for for a donor. Double-check (4.30 has 43 teeth on the ring gear, and the ring gear is often stamped 4.3) before you install anything.

If your truck is a Prerunner (6-lug RWD), you've got more flexibility. Use whatever third member you can find and correct the speedometer to match.

If you have 4x4, your front and rear diffs need to match. The most common gear ratio in 1st gen Tacomas was 4.10, so that's what you're most likely to find used. If you're sufficiently handy, or willing to pay a shop to do it, you can either re-gear a 4.10 3rd to 4.30, or you can replace your front diff with a 4.10 (or any other ratio you find--and again, correct the speedometer to match).

If you can spring it, the most convenient option is probably East Coast Gear Supply. They'll sell you a remanufactured third built to your specs. You could even get a limited slip diff or (as mentioned previously) an Eaton e-locker as part of the deal. Unfortunately it doesn't sound like your existing diff is in good enough condition to be used as a core, so you'll either need to pay the core charge or find another diff to use as core. https://eastcoastgearsupply.com/i-788575-tacoma-8-4-non-eld-t100-tundra-3rd.html

 

My 1999 TRD 3RZ Automatic Prerunner came with 4.30 gears. It did not have the e-locker since that engine/transmission/drivetrain combo did not get it. (I swapped one in through)

 

I had the info years ago, but don't have it anymore and don't really care to look it up. I've seen it done. I agree it's a lot of work, and it's stupid to do, but it's definitely doable.

Even swapping the whole axle is too much work. At the end of the day, you're just using a stock locker that is known for engagement issues. That's why I always recommend for people buy an Eaton E locker and never look back.

I even have a complete OEM locked rear axle sitting in my garage that I have no idea what to do with.