End-goal for me is to reliably fit 37's w/ front and rear lockers and a lower range t-case so I've been doing some research.
Somebody PM'd me a while ago and I did a quick write-up for them on my opinion with some numbers thrown in. They had asked about my ECGS rebuilt 8" diff. Some of it you may already know but for anyone that is curious here it is.
**Disclaimer: This post mostly benefits those that do serious high-traction rocky trails where low range is used, and greater than 33" tires are equipped.
Currently mine and my brother's ECGS rebuilt diffs have been doing fine, but really only have a half-dozen of rock crawl outings with mine so far (35's). If you look around the forums on build threads with broken 'original' rear diffs guys aren't back the next weekend posting another broken gearset from what I have seen (maybe they are more cautious with the skinny pedal, but it seems the rebuilt diff is stronger) The stock gearset with 120k miles and the crush washer with 34's or 35's in my mind is guaranteed to break after a couple heavy trail runs/obstacles if you are not the utmost of careful (which is no fun, makes me sweat more). As I have posted before, guys on this forum inevitably seem to break their original diffs once they move up to 34's or 35's.
If you had front/rear lockers (recently rebuilt diffs with solid pinion spacer) I could see potentially less stress being put on the diffs due to less wheel spin/speed on the trails. The rebuilt diff w/ solid pinion spacer is way better than your 10yr old diff with a crush washer. If you added a crawlbox (
Marlin tacobox, $2.5k) or aftermarket t-case (Atlas) with a lower 'low range' gear ratio you could probably easily get by with rebuilt 8.0s as a guy from Marlin runs 40" tires on a 3rd gen Tacoma with their tacobox (their rear diffs might be a little stronger though). With the tacobox you have way more control and time to 'not break' stuff. I've also heard the lower gearing helps a ton with rock crawling capabilities.
I'm not sure how much stronger the 8.2's are as they use the same size gears (or maybe slightly bigger?), they just beefed up some things to hold the gears more rigidly I guess. You don't hear of too many of these diffs breaking, but they are found in newer trucks that don't seem to wheel as hardcore (or have as big of tires generally speaking). The one I did hear of breaking (newer FJ) they broke an axle instead of the gearset, after ~7 years of wheeling with 35's. Personally I wouldn't spend too much money on an 8.2 upgrade, it's not really proven in my mind
yet, but if you can sell your complete stock diff you could recoup some cost and if you can find a good deal on a used one it should bolt right in.
My brother just told me ECGS can build a mostly-complete 8.2 diff that you can throw your existing axle shafts/bearings and things into. You might want to ask them about this (it doesn't appear to be on their website) and if you do, I would be curious to know the details. I just looked and
JustDiffs.com
does the same thing, cost with ARB/4.56/chromoly axles is $3800 plus shipping.
It really depends on what expectations you have for your truck. If you are more careful than most, do medium difficulty trails with 33's close to home, and rebuilt your old diff with a solid pinion spacer and locker, I would wait to see if that gearset goes before thinking about upgrading. If you throw on a set of 35's and walk the thin line of your truck's capabilities, I would definitely consider the 8.2 if not more, especially if you occasionally wheel 1000 miles from home like me. My brother's ECGS gearset in his FJ has held up fine with 34's, after his stock gears died, for 1.5 years but he has a Diamond 9.5" diff on order because he is planning on 35's or larger, a bunch of other stuff, and doesn't want to break down in Moab or California when we are on vacation. I have a similar plan when I have the time/money.
You said you like the elocker option, in some ways it is nice and cheap, with the ARB you can have more things go wrong (seals blow, air mixes in with gear oil, etc) and needs an air compressor setup, couple hundred bucks more.
In summary, here are the options as I see it with prices mostly from my brain. Not knowing what tire size, gear ratio, or trail difficulties you want to run in the future, I listed about everything that made financial sense. The FJ guys have a good option that we don't have as cheap, which is sending in their elocker 3rd member gearset for a rebuilt gearset. Ours would be a couple hundred dollars more I would think, for that exact option because we don't have a rear locker from the factory.
* An ECGS rebuilt diff has a 5 year warranty with 35" or less tires.
* Regear will require additional cost of regearing front diff as well (check ECGS for prices)
* Recoup costs not include in estimates.
I'll say it again, this is a pretty rough estimate of costs depending on shipping costs, what spare parts you sell, or what locker you choose.
- $0 Stay with 33's and hope to not blow the diff knowing that it could break if pushed hard, if you do rebuild/regear/ARB.
- $600 Find used 8.0 3rd member with elocker unbuilt 3.73 gears, and retrofit.
- $800 preemptively rebuild existing 8.0 to avoid paying tow truck and trail-shame, regear/no locker.
- $1200 Find 8.0 3rd member with elocker already rebuilt/regeared (Or send ECGS your non-elocker + added cost for an elocker diff).
- $2000 junkyard/used rear 8.2 w/ elocker, sell current 8.0 assembly to recoup cost.
- $2800 junkyard/used rear 8.2 w/elocker/rebuild/solid pinion spacer/regear. Sell current 8.0 assembly to recoup cost.
- $3300 Marlin crawlbox with ultra-low gearing for added control/capability plus preemptive 8.0 rebuild/regear/ARB.
- $3300 ECGS Dana 60 w/Ox locker, reuse stock shafts, can upgrade to chromoly 30 spline shafts later if needed ($500) and is stronger/bulkier than the 8.2
- $3500 Just Diffs/ ECGS 8.2 with standard axles/ARB/regear. Sell 8.0 3rd member to recoup cost.
- $4000 Just Diffs/ ECGS 8.2 with chromoly axles/ARB/regear. Sell 8.0 3rd member to recoup cost.
- $4500 ECGS Dana 60 with 35 spline axles/any locker/regear. Sell entire 8.0 axle to recoup cost.
- $5500+ Currie F9/Diamond 9.5" ARB/regear necessary. Sell 8.0 3rd member to recoup cost.
- $8000 Diamond housing w/ Tundra 10.5" gears. Sell entire 8.0 axle to recoup cost.
Maybe this makes you more confused, but I hope it helps you out. If not it's a good reference for me to look at... Might make for a good thread some day.
Also, my brother put together
this guide for axle basics/terminology.
