Diff experts… which are compatible in first gens?

This may or may not be a question for an expert but I’m trying to learn what I can lol.

I want to swap out my stock B06A diffs for 4.3 diffs.


(I’m looking at a 2000 tacoma diff to put into my 1997 tacoma… both are A.D.D.
I’ve been hearing it will bolt right up, but if you know differently, I’d like to know. I have a 6-lug 1997 4wd MT 5vz-fe with the R150. Running extra weight & 33s.)

 

I'm like 90% sure B03A is 4.10s EDIT: Looks like you corrected your post to say B06A.

I'm also like 95% sure all 1st gen Tacoma E-Locker axles came with 4.10s

For a rear E-locker swap you want to buy the entire rear axle from a Tacoma, drum to drum. The 3rd member alone is not bolt on interchangeable. The axle housings are different between open diff axles and e-locker axles
4Runner axle will not bolt on, since it is made for coil suspension not leaf springs like your truck.

 

thanks for the reply! I had to edit my post as I learned, lol.
I started my research with open 4.3 front diffs since my front diff went out on my truck.
So it would be “impossible” or a big struggle to add an e-locker to the rear if I were to source a 4.3 rear differential?

 

Nothings impossible.

Its a bit of a weird path to go down though, 4.30 is kind of an uncommon gear ratio to use in a Tacoma regear. Not that it might not fit your needs well.

Just so I fully understand the situation; Your truck has 3.91s. Your front diff blew up.
You are looking into options to replace the front diff, regear to a higher ratio, and are interested in putting in a rear locker while you're at it.

Is that accurate?

 

Yep- accurate!
I just want a rear locker.

4.3s might not be a common choice.
I considered 4.10s but I don’t think it would make a lot of difference.
4.3s seem nice because the truck sees a lot of highway miles. I don’t want to see a huge decrease in fuel efficiency, but want to feel the difference in power. I hit some occasional steep, slippery trails but I don’t think I’d want 4.56s or 4.88s for the majority of what I use the truck for. (?)

 

So what I’m finding is,

Front diff is 2 pinion only.
Rear elocker is open until you lock it.
(There’s no lsd 4.3 from what I can find)
And I believe my truck has a 8” front differential, and 8.4” rear end?
So I would have to get whole axle housing with the elocker?

Does that seem right?
There’s some forums on modifying the non-e locker housing….
Seems maybe I’m over complicating things as usual

 

Yeah I do wish I had 4.30s over my 4.10s, but if I were to regear I'd go 4.88s.
I know nothing about about the front diffs, but yes the open rear diff is the 8.4", the e-locker rear is an 8".

The easiest/cheapest path is to get a Tacoma e-locker axle with 4.10s and swap it in, and then regear or swap the front to match the 4.10s. 4.10s are probably the most common ratio for these trucks, so finding a front diff with 4.10s shouldn't be too difficult.

Next would be Tacoma e-locker swap, then regear both that and the rear to 4.30. But since you'd be paying regear install (unless you can do it yourself) I would suggest going to at least 4.56 to make the money spent worth it. I wouldn't do under 4.88s personally, but I have future dreams of 35s. But if you're paying for a regear, an e-locker swap doesn't make as much sense. Might as well pay someone to just install an Eaton or ARB locker while they do the gears instead.

I cant say if a 4Runner ADD 4.30 front diff is bolt on, I'm sure someone else can chime in with information on that. However, I can say that the 4.30 4Runner rear axle is not bolt on.

At a minimum you would have to cut off the coil spring mounts and weld on leaf spring perches. No idea what differences there might be with parking brake cables and brake hardlines to complicate that though.

Or you could buy an empty Tacoma e-locker axle housing, buy the 4runner 4.30 e-locker 3rd member, and install the 3rd member into the Tacoma housing. Then it should bolt on. Then if the front 4runner diff with 4.30s also bolts on, you just regeared and added a locker without paying for a gear install. Its a bit of a janky path, but could work. Similar path would be fabricating Tacoma leafspring mounts onto the complete 4runner axle housing instead of swapping the 4runner 3rd to a Tacoma housing. If thats in your skillset, its an option.

OR since this is all getting pretty complicated, you can just regear your existing diffs through a company like East coast gear supply, and install an aftermarket e-locker or air locker through them. Could get a front locker while you're at it that way.

The E-Locker swaps make the most sense when you do not want/need to regear. If you are already regearing, you are likely already paying the labor to take the diffs apart and install the new gearset. Since thats already being done, adding a locker doesn't add much outside the sticker price of the locker itself.

Honestly avoiding diff work labor cost is basically the entire reason anybody e-locker swaps. If you're paying it already, theres little benefit to going that route.

 

Factory 4.30 gears are hard to find, and did not come (or are extremely uncommon) in the e-locker axles.

By far the easiest and most commonly found parts route for you would be to buy a whole front differential and rear 3rd member from a 4.10 non-elocker truck. Then add whatever locker or LSD you want to the rear. Otherwise, a 4.10 front and elocker rear (need the whole housing drum to drum), along with wiring harness and switch for the elocker.

 

You said "I want to put an E-locker in the rear… which I think means it will be an LSD". An e-locker is not an LSD--they're very different, and have different pros and cons. There are also different types of LSD, which each have their own pros and cons. You should understand the differences before you spend any money. This is a good summary I found: https://www.crawlpedia.com/locker_comparison.htm

With that out of the way, your questions:

All 3rd gen 4runner/1st gen Tacoma diffs are interchangeable.

There are three different extension tube designs: straight (for manual hubs), vacuum-actuated ADD (earlier trucks), and electronic-actuated ADD (later trucks). I don't know exactly when the changed from vacuum to electronic actuated happened.

The easiest path for a front diff swap is to find a donor that has the same extension tube. If you can't do that, you can swap the extension tube from your original diff on to the new diff.

4.30 gears can be found in 1999/2000+ 2.7L manual-transmission trucks. These trucks are unlikely to have an e-locker axle--I can't say for sure that 4-cylinder elocker trucks don't exist, but I've never seen one.

4.30 gears can also be found in TRD 4Runners. This is where you'd find your factory 4.30 e-locker, however a 4Runner axle is different from a Tacoma axle, and open (8.4") Tacoma axles are different from e-locker (8.0") Tacoma axles, so you'd need to find a Tacoma e-locker axle housing in addition to the 4Runner diffs.

Given extra weight and 33s, you might also consider a 4.56 front diff. Those can be found in 2.7L automatic 4Runners and Tacomas. I highly doubt you'll find a factory 4.56 e-locker, though. I've seen claims that they exist online but they're very, very rare.

If I were in your shoes, I'd find a junkyard front diff and buy a complete 8.4" third member with a Harrop e-locker or TrueTrac diff from ECGS: https://eastcoastgearsupply.com/i-788575-tacoma-8-4-non-eld-t100-tundra-3rd.html

That's the simplest path. It might cost a bit more money but it'll save you a ton of time and effort cobbling all those parts together.

Don't forget wiring if you go the e-locker route. You'll either need to retrofit the factory e-locker wiring harness or buy an aftermarket harness.

 

For rigs that are mostly street driven I like the Truetrac. I don't have one in my Taco yet but I have used them in older Land Rovers and really liked them. Worth looking into if you haven't. Not really a full locker but they are a great compromise.

 

I'm also on team TrueTrac. I've never driven one (also never driven an e-Locker) but from everything I've read they seem better than an e-locker for most people most of the time, by a wide margin. TrueTrac is cheaper (unless you get a good deal on used parts) and easier to install than an e-locker too.

It's on my "someday" wish list, once I decide what gear ratio I want to keep. I've got 4.10s now, but also have 4.30 and 4.56 diffs on the shelf, waiting for me to get the motivation to install them.

 

You want to look for a TRD single cab,2.7, auto, 4x4 in junk yard you wont get 4:30 more than likely it will be 4:56, dont know if this combination exists, but it will have rear locker, dont shy away from the 4:56 its pretty good on the street with taller tires and v6. A lot of prerunner 4cly autos came with 4:30s maybe find a TRD one?
As far as 4:30 front diff…..never heard of it.
R/

 

The thing I like about that diff is it has benefits for daily driving, and that is what I do most of the time, and frankly I get by with open diffs for the wheeling we do anyway. Got a winch for when I could have used a diff hehe.

 

I went the route of paying a shop to install an Eaton E-locker into my rear diff (8.4" open diff originally).

Here's the factors that led to that decision:
1. My wheel bearings and axle seals were brand-new OEM. Buying a used factory Elocker housing likely would have meant I'd have to do that job again in the near future (and it's a bear of a job).

2. My rear drums/shoes/hardware and wheel cylinders were all brand new OEM too. These would've transferred over to the Elocker axle, but drum brake work is a headache I don't really enjoy.

3. The Eaton Elocker is far superior to the Toyota OEM one (quicker engagement/disengagement, far easier wiring, and an overall more robust design and mechanism).

 

How much use have you had with it? I do like that design. If I was going with an on/off locker that would probably be my choice. They seem pretty ideal.

 

I have used it a quite a bit. I had it installed last spring and did a lot of elk and duck hunting the last couple of months. Where I hunt there's quite a few spots where without a locker, you'd be hard pressed to get through, and you'd need a lot of skinny pedal and momentum to do so.

The locker alleviates all of that of course, and it has never not engaged within a second or less of me hitting the switch, nor has it ever not disengaged immediately either.

 

thanks for your help! I’ve been finding 4.3 e-lockers (just in case you find it interesting that they came stock in some trucks, id bet they were mostly 2wd)
thanks for being the first to explain the 8” vs 8.4” diffs & housing to me.

I am now deciding between these options:

Choice #1:
• replacing my 3.91 rear end with a 8.4” with 4.3 open gears
Adding a locker later.
Reasoning:
• I can install myself
• 8.4” member is stronger
• 4.3 is the closest gear ratio to get me back close to stock. (With 285/75 r16 4.27 gears would be like my 3.91 gears based on a gear ratio tire size calculator I used.)
• based on above reasoning (not overgearing, but trying to match stock ratios) more power, slight improvement of no negative affect in mpg is more likely than with 4.56 or beyond.
• on steep terrain 4.3s will help my truck take off, handle better than 3.91s. Maybe.
Cost: $905-1300 to install myself with used, assembled factory parts.

Choice #2
Just replacing my 3.91 front diff and adding a locker to my rear diff when it makes sense for me.
• can probably still do myself.
• can put in the rear locker later, since I only need to do front differential r&r (mine is destroyed hence the decision at hand).
• I’d still have stock 3.91s with 285/75r16 but I’d have a locker.
• front diff $405. could probably do the locker install & front diff r&r for the same cost as choice #1. have the advantage of time to find the locker I want.


third option:
Looking into e-locker full axle replacement with 4:10s like suggested. I really don’t think this’ll be the cheapest and easiest route like suggested. I’ve been seeing a lot of complete axles for around $1500. And I live in a *super* rural area so that’s without factoring in shipping, or driving.

fourth option:
same as above, but with 4.3s. same reasoning, + I’ve already sourced em. “better” gears.


Seems you guys seem to prefer other options to the e-locker anyway.

 

$1500 is a lot for a complete axle. Being "super rural" obviously affects supply and demand, but complete e-locker axles are commonly found for $700-$1000 in Colorado and California.

An upside of staying with an 8.4" axle is that diffs are relatively easy to ship once they're out of the axle. You should be able to get a pair of salvaged 3rd members shipped to you for a lot less than $1500 if you can live without the e-locker.

Maybe post in the Buy/Sell/Trade and see if anyone has a set of 3rds lying around? People are upgrading diffs and solid-axle-swapping trucks all the time.

 

Being rural isn’t where the $1500 comes in for a e-locker axle. That was in Rancho Cordova / Sac area where there’s a supply of these trucks & parts. It’s additional money for me tho, for me to get that shipped. That was for an e-locker with 4.10 gears too, supposedly the most common.

interesting to hear they are around for $700… I haven’t seen that, where have you seen those kind of prices? @6P4
I found an empty e-locker housing for $700, but then the 4.3 e-locker third member is another $750+
At that price point point, I might as well keep my 3.91s and add an Eaton locker or something.

like I mentioned,

I did find front & rear diff in the gears I’d like for $905. No locker, though.

Since I like to be thrifty parts availability can sway my decision.
I checked the buy/sell section to no avail

 

Rancho Cordova is home to some large Toyota part-out operation. Their ads pop up on Denver craigslist under "for sale by owner"; super annoying when you're trying to find actually-local actually-for-sale-by-owner parts, so I don't have warm fuzzy feelings for any seller in that area.

Here's an $800 example in California: https://losangeles.craigslist.org/sfv/pts/d/canoga-park-2003-toyota-tacoma/7819078039.html
Here's one in Colorado: I previously purchased a complete axle for $1000 and then sold it for the same amount after deciding to keep my 8.4".

You need patience and a bit of luck, but they do exist. Of course it helps to be in a dry (non-rusty) region where Tacomas are popular.

I would say, if you're going to spend the money on an Eaton rear, get it in 4.10 or 4.30. That's a lot of money to spend on a rear and not get the gears you want.

Front diffs are relatively easy to find in junkyards--I can reliably find 4.10 and 4.30 front diffs, but it can be a month or two between good donors showing up. Rear diffs are harder to find because they get picked over quickly.

For your reference, the yard local to me currently charges about $120 ($90 part price, $10 env fee, $10 core charge, + tax) for a differential.

That still seems like a lot for factory gears without shipping, but if you can talk them down even a bit it might be worth the price for convenience.

You can post a "Wanted" add. No harm in asking.