Spartan Locker

Looking to run a spartan locker. Does anyone have the specs needed to order one for our base model trucks?

-PyroTaco

 

Are you manual or auto?

 

Auto

 

good so you wont have to change 3rd members. Anything made for a Tacoma 8.4 in (also called 8 sometimes) diff should work. As long as its not for a e locker( different size) I also suggest if your opening it up to change gears to.

 

Thanks for the info

 

What about a manual?

 

With a manual you will need another 3rd member since the manual is smaller for some reason.

 

Manual or auto does not matter, neither does 5 lug or 6 lug, all 2nd gen Tacoma's (non OEM Locker) have the same rear differential (not axle) referred to (rightly or wrongly) as the 8.4".

It is used on earlier gen Tundra's an Sequoia's also. You can get more than a few limited slip diffs for it which you'll want because you I don't think you'll want a locker for a 2WD Tacoma, the LSD will do 98% as well as the locker.

https://www.justdifferentials.com/category-s/2659.htm


It's easy to tell from earlier 8"diffs. It looks like this. The first is to illustrate the bearing cap bridges, or "handles" that only the 8.4" has. It also shows an OEM Limited Slip Carrier. If it was an open diff (as most are) that casting would be much more open and you could clearly see the spider gears.

 

Manuals are smaller. There are a few people that have already cracked their axles open to find out they need a 8.4 diff. I think the manuals are like 7.4 but you can swap in a 8.4 and be done with it. It's just if someone wanted to only regear they would need a new 3rd member.

 

On first gen Tacomas that may have been the case. Almost all diff identification information online refers to first gen Tacomas and really goes no newer than 2000. I've looked at a lot of references, there is much less on 2nd gen Tacoma's. If you take some time it can be figured out.

All 2nd gen Tacoma's use the 8.4", the under the truck picture is my actual truck, it's a 4cylinder automatic and that is a 8.4" diff.
Why would a manual trans truck have a smaller and weaker differential? It wouldn't.
A manual trans in the same truck is never going to have a smaller and weaker differential.
An X-Runner (it's a manual only) is going to have a smaller and weaker diff? No.


Follow the link I provided for the LSD, it shows what it fits and it fits the entire 2nd gen Tacoma line except those with an OEM Locker.
Another way to tell an 8" from an 8.4" (if it's out of the axle) is the number of ring gear bolts, the 8" has 10 the 8.4" has 12.
2nd gen Tacoma's didn't use the 8" or anything smaller.

 

I thought the e locker 2nd gen was 8” and everything else 8.4

 

It's been a while since I've looked into diffs. I ended up doing an entire axle swap to an elocker axle (so 6 lug rear and 5 lug front). If you look in this thread they explain how the diff is similar in size but slightly different. I usually just suggest if people are manual to buy a completed one new or used and just swap it in.

@HackD got this

https://www.tacomaworld.com/threads/regearing-5-lug-to-4-10.319914/

 

The way to look at it, is this - the 3.31 geared MT differential has different pitch and count of teeth in the differential, that is non compatible with 3.58 and up replacement. 3.31 is it's limit.

The non-TRD diff's in tacomas are commonly referred to as 8.4" even though the ring gear still measures 8".

We need to use the non-TRD's for the 3.31-3.58 upgrades, as the TRD differential has a non-compatible e-Locker that has the differential profiled differently as far as internal machining to fit the e-Locker components.. non-cross compatible in terms of parts content with a 5-lug axle and driveshaft

Both Base, and SR5 Trim levels will work in terms of cross-compatibility of donor diff's. Look at the T100 (non-TRD), the 2005+ PreRunners (non-TRD), and 2005+ 4x4's (non-TRD) for donors of complete differentials cross-compatible to either the 3.31 or 3.58 for replacement plug and play, or simple gear replacement parts only for the 3.58.

Other models may work, but that research is on you... I took it only so far, and made my selection based on the above basic research. My 4.10 ended up coming out of a 2014 Base-trim 4x4 wreck, as a complete differential to rework with a LSD, to replace my 3.31.

The 3.31 is more useful as an 80lb boat anchor, than as an upgrade path - i have seen someone attempt to retrofit a 3.31, and documented it online.. it wasn't a success.

 

All ratios have different pitch and teeth count than each other, that's what makes the ratios different . . .

Here's what I'm saying, all non E-Locker 2nd gen Tacoma's have the 8.4" rear diffs, I mean the pig casting. No exceptions. There are different ring&pinion ratios and a few have an OEM LSD but I am not talking about that.

Are you trying to say that 3.31 and 3.58 diffs are distinct physically and cannot have a different ratio ring and pinion put in them? so you have to swap the whole pig?

 

You now have me rummaging through memories about 5 years old. There is a distinct, and non-compatible difference that makes the 3.15/3.31 non-upgradable further, related to the Carrier, and spline pitch.

Not saying any differently. The '8.4' is what we have. The '8' is the TRD e-Locker type. OEM type 'LSD' (The TCS 'switch') on ours (2009+ IIRC), is using the Antilock brake system to induce power transfer - not from the differential itself.

3.31 is a Dead End. 3.58 is upgradeable to 4.33, IIRC..

It has to do with the Carrier inside, and the spline pitch. There was a video up on this a long while ago i'm trying to find, that explains it far better than i can.

 

Here's the guy with the failed attempt - 5 years ago. He was trying to upgrade his 3.31.. he had a part 1 up, in which he went through minutia of issues he was coming up against, as video went along.. Part 2 is him saying 'fuckit, got me a 3.58 to upgrade instead'.

https://www.youtube.com/watch?v=uL-v-iYcg7k

There was also a website up of a driveline guy that had all the stats of various Toyota differentials up, that explained the differences in black and white.. i can't find it now..

 

I don’t have experience with them first hand but Ecgs won’t accept 3.31 diffs as cores. Which says to me they’re incompatible with the 8.4 ring and pinions

 

I haven't reviewed them in full again, but this guy has some mechanical/machining experience, and if he gave up.. just sayin'..

Part 1 - https://www.youtube.com/watch?v=8yItw75pAmo
Part 3 - https://www.youtube.com/watch?v=K8dPIR1uqVk

 

Correct. I tried to give my 3.31 away. No interest to anyone, except to perhaps an X-Runner owner who wants a negligible up-gear and plenty of time on their hands to switch and swap.

Ended up in a dumpster with a very heavy thump. I had even offered it up to the guy who re and re'd my replacement 4.10. He laughed, and helped load it in the back of my truck, to make sure it didn't compress his bench further into the concrete.

 

That’s an hour of video showing him swapping a ring & pinion at home and about 2 minutes of him saying he “had a snag when I want to set up the original 370 gear-set” and “ it seemed like the original carrier is not a sufficient carrier to handle a 370 ratio” and “no way I could get an adjustment at all with the 370”.

NO VIDEO of the actual issue.
Then rambling on about GM carriers. Not a lot of clarity there.
Maybe there was an issue with the crush sleeve (basically the only adjustment) though he seems to know how those work later.

One could deduce that the 3.31 carrier (not pig) could be distinct from all other (open) carriers used by any other gear ratio sets used in 2nd gen Tacoma's.
I’m not sure I buy that based on 1 persons experience but it may be correct.

He could have saved himself the bother of having to get a whole new pig at that point and buy a new LSD carrier (you could get a new open carrier but what’s the point) and using the gears and pig he already has. He needed a new (different) carrier not a whole new pig.

MORAL OF THE STORY
If you have 3.31 carrier in an 8.4” diff (and we are assuming 3.31 is distinct from all other ratio carriers) and you want to change ratios, but an LSD carrier at the same time.


PS: X Runners use 3.15 to 1 diff ratio and have a standard LSD, should we assume that these have a distinct carrier based on the ratio? I don’t.