Axle Swap Worth It?

Truck currently has a 8" with factory e-locker and 3.73's.

I also have a 8.4" SR5 rear axle sitting in my garage.

I'm looking to regear the truck for 33/35's.

Is it worth swapping the axles, buying a locker for the 8.4", and regearing that?

Or save money and keep my 8" axle, regear it? I'm buying gears anyway; I guess the main difference is the cost of the locker and hassle of swapping axle.

I've read that the 8.4 is stronger, but only marginally.

 

I'd say stick with the 8" and e-locker. If you go 33's no need to regear for normal use,. With 35's, 4.30's have been a good sweet spot for me. It's a little over geared, so good take off with no struggling, but not so much that RPM's scream at highway speeds.

 

I have 33’s on stock gears currently, looking at 35’s/4.56.

 

Aftermarket locker is more reliable than stock locker. 8.4 has a stronger carrier than 8" because of 1 piece cross section.

 

I swapped a 4.88 Elocker rear into my Sport last year. Broke it 3 times and put back in my stock Sport rear again that has 205k on it and have had zero problems. 34’s for tires N/A engine Anymore questions

 

Were you breaking the locker or the ring gear?

 

What tires at 34"???

 

285 75 17 is a 34.

Depends on specific brand too as tire sizes are more suggestive than accurate.

My Cooper ST Maxx "34's" are taller than a friend's ProComp "35's".

 

Regear. Put lockers. 8.4” rear. Do it on spares and swap them in. Done

you already have a spare 8.4” rear
Finding a front diff clamshell shouldn’t be too hard.
Regearing takes time. That means the truck being dead and disassembled for many hours.
Regearing spare units takes care of that headache.
Especially if it’s your first time and you need to take breaks here and there to figure things out.

that’s what I’d prefer to do. Except a junkyard quoted me $1200 for front and rear diffs. Which is insane. A couple of shitty old stock diffs for $1200. I literally bought an entire driving parts car for less than that. And a complete manual swap kit for $400 which included not only two diffs, but a transmission and more.

Not according to my load e 255/80r17 and fuel gauge

many cars come with 3.9 and 4.10
Old 4Runners did
The fact Toyota put 3.73 in these trucks is simply a bad joke

 

Not from an 8 to an 8.4.

If you're gonna diddle around with housings move up to at least something amounting to an upgrade, which means RockJock. And of course, if you do that, now the front end is wildly weaker.

Just regear unless you're willing to SAS.

 

The 8.4" housing was inexpensive. I'd love to move up to a Diamond/ECGS or similar, but don't have the money for it.

 

Understandable. Anything short of that aint really an upgrade though.

And axles that beefy on these trucks, you're not gonna need them unless you're rollover-risk wheeling. And if you're doing that in a full bodied late model tacoma you've already messed up a few steps on the way there. Get a 20 year old shitheap for that stuff.

Ive never seen a situation where axle upgrades make sense yet on 2/3 gens.

 

Ring and pinion l. 275/80/17 Goodyear MTRs. After the 3rd warranty ECGS offered to build me a drop in D60. I kinda got side tracked gathering parts for my 63 swap. I think I’m just going to put an ARB and gears in my Sport diff. I shouldn’t need a D60 in a Tacoma.

 

Good to know!

 

Shouldn't need a D60, but stuff happens lol. I'd like one, but again, $$$.

 

The cost of putting an ARB locker and regearing the 8.4 is not worth the little bit of extra strength. Running TruTrac in an 8.4 isn't ideal if your on the street alot. ( I have one). With 4.30 gears and tires that measure 34.5 inches about 65-70mph with a 5 sp AT you run out of gear and my gas mileage starts going down because the RPMs start climbing. 4.56's I just wouldn't use on the highway.

Just going off of my experience. I did a full post on 4.30's real world a couple years ago.

What year is the 8.4 ???

 

I would swap to the 8.4 axle and sell the elocker and housing to fund the 8.4 locker. Swapping axles is easy so really your question boils down to is the cost worth it, which selling the e locker mitigates that. So for a little bit of labor and not much money, you have a stronger rear end.

 

OP got the 8.4 for free or cheap
There’s many lockers to pick from. Usually open on the street and locked manually off road

6MT likely solves that with a 6th gear

 

I believe the 3rd gen TRD Pro's come with EL and 4.30's, anyone ever try to transplant 3rd gen axel and diffs into a 2nd gen?

 

I believe gear ratio is dependent on transmission. All autos get 3.73 and manuals get 4.30. So a manual trd pro would have 4.30 and e locker.

No idea if anyone has done the swap but I do know the third gen e locker is a different design than the second gen and is more difficult to get it to function standalone. Would be cool to see it done though.