Thinking about installing locking rear differential (1 Viewer)

[knuckle47]

I am thinking about adding a locking diff to the rear of my FJ40. This is an area I am not well versed in….Read several pages of threads about the Air Lockers and Aussie Lockers. I am looking for a little guidance from this viewpoint.

I don’t use the FJ40 as a daily driver but occasionally some sandy beach fishing and deeper snow driving. I have rarely if ever had an issue getting stuck somewhere because of traction loss. I tend to believe with the air systems, the possibility of any external components failure could be a problem. The fact that I would use the vehicle less than 4000 miles a year or less and the Aussie locker is 1/3 the cost makes it appealing. I have also read a ton of great comments about the air system and how if the cost was not a factor…go with the air.

i think I am looking for just a “simple” positraction like I have in my Chevy pickup. In other words …nothing to have to think about.

so for those with experiences in this area, what do you think? Ease if install may be a consideration as well

 

[bj70bc]

if you dont want to think about it and you arent daily driving it its hard to beat a eaton/detroit autolocker,
they are bulletproof, will differentiate around corners when you arent on the gas, and when you punch it they just work...simple.
nothing to go wrong, and are better than a lunchbox locker (lockrite aussie etc) as they will take more of a beating
i have em in the front and back diffs and they are great.

 

[aztoyman]

I have Aussie Lockers in both axles on my mini truck. They are definitely simple and affordable. However, many people don't like them. They definitely require you to adjust your driving style. They are locked until one wheel is turning faster than the other as in a turn. Then one side ratchets. They click and bang. I tend to coast around a corner on the street. That said, they work.

I've had Detroit's as well. Same operating principle. The Detroit is definitely beefier and more expensive. I doubt I could tell the difference between a Detroit and an Aussie by just driving them. The Detroit is a stronger unit though. I've been running my Aussies hard for over 13 years without issue.

I've also heard they are horrible in the snow. IDK, I live in AZ. I have driven in snow a few times off road and I had no trouble. On the street they are reported to be sketchy in the snow and you can't just turn them off like a selectable.

The Aussie is cheap enough to try I guess. Easy to take it back out and sell it.

To add, You might like a Detroit Tru-Trac. I've had them in both axles on the same mini truck. They might be a good choice. Technically more of a limited slip but no clutches to wear out like a Posi. They were great in sand and just about everything until I lifted a wheel. I sold them and put in the Aussie's.

 

[mattressking]

Electric is the only way unless you find an oem cable locker for general easy maintenance. Eaton/harrop is the way to go. That said they are pricey.

You could also use an 80 series rear diff if you find one….notch the diff housing and you’re on your way. Cool guy it with a new oem on/off switch and a custom knob and you’re stylin.

Air is cool, but I hear more issues long term than not. No personal experience but as a truck driver, anything operated with air is prone to leaks and having to open the diff to fix air a potential leak is not part of my to do list. That said a perfectly setup ARB is fine, I just don’t like modifications that open up opportunities for issues. Like the Eaton/Harrop, they are pricey…..a little extreme for a car that gets 4k a year and doesn’t rock hop.

Lunchbox lockers are annoying as hell. I drove mine daily with one, not worth it at all. Way worse than a clutch type LSD and value added just isn’t there for me.

If it were me I’d strap some boards on the spare and use those if you get into a slick spot at the beach.

But since it’s not my money, go have fun and get the Eaton/harrop!

 

[pb4ugo]

As others have said, a lock rite, aussie, lunchbox locker are quick, easy and cheap, and you won't forget they're there. They'll bang, clunk, and work. It will pull to the right on hard acceleration and to the left on deacceleration. I ran them for yrs. I run an actual Detriot locker in the rear of 1 of my 40s and it's great. Its mostly quite, and rarely a slight crunch or click but nothing violent and handles great. It's nothing like a lunchbox. I truly forget it's there. They're not cheap, but not as expensive as an ARB, and you do have to setup the carrier. The same vehicle has an ARB in thr frt and I would do it again. At some point My other more street friendly 40 will get an ARB or maybe a Detroit in the rear and an ARB in the frt with alloy birfs. It will see more pavement than trail. A quality winch works too.

 

[Green Bean]

Similar decision tree analysis here. Beach driving; no hardcore rock crawling. I read through the FAQ on lockers and ended up opting for a rear ARB. Parts are inbound so I haven't installed yet. @BenjaminCA has a good video documenting his installation of an air locker on his 40.

 

[knuckle47]

Wow! Overnight and it seems you ALL have answered my question….and I thank you for it. Now that I have a bit more exposure to this, I have a bit more reading to do.

when I was an active four wheeler in the mud and snows of Vermont, I never had issues getting stuck some where and in fact, pulled out a few jeeps back then. Now that I am a solo adventurer… and a lot older, I’d hate to get stuck somewhere. Although, we didn’t have cell phones then…

 

[Living in the Past]

Factory cable and E-Lockers require a full floating axles. Then the right inner axle has to have a special long splines for the locker. For the 40/60/70 series that inner axle is NLA. The factory limited slip also require a full floating axles. But not the longer spline inner axle.

ARB are available for both semi and full floating axles.

Not sure what the Harrop requires.

I purchased Lock-Rights for my coarse spline 68 years ago. Was the only thing I could find for coarse splines. Besides the noisy back it also clunks. I have to be careful shifting on icy roads it has a tendency jeck sideways when pressing to hard on the accelerator. Not familiar Detroit or Auburn. But I have a set of Torsens in an old cruiser. I prefer those over the Lock-Rights. The Torsens were in the original Humvees and used in racing. Toyota was and may still be using them in full time 4WD transfer cases. Would use the Torsen while in open 4WD. Believe Eaton makes one that is a combo Torsen/E-Locker. Unfortunately wasn't being made for the Toyota 9 1/2". If it was this would be my first choice.

 

[knuckle47]

My attempt is to also minimize the hunt for parts and pieces that may be difficult to obtain and simply open the box, take apart the differential and install the new one.
i decided to add FJ60 front disc brakes. It took me a day to find them and 2 weeks to clean them up and start the caliper rebuild. When I was 35, this was fun stuff…. At 70, my goal is to get the job done without the major input of energies or it may just get blown off and skipped…. I’d hate to start a project and find it sits there too long incomplete and unfinished. Using a ‘KIT’ helps me get things done these days.

does someone know the size gear in my 1975 FJ40 ? I have not taken anything apart and I’m thinking all of this from my recliner and not the shop. The shop dreams are less expansive and the recliner dreams are grandiose

 

[Mark Jennings]

I always thought a limited slip in the rear, with a locker in the front was the best all around combo. I think the Aurburn Pro limited slip, uses clutch cones, would be a good choice for the rear and could be used on semi float axles with the ‘C’ clips. In the front, since it is actually a full float, I’d soot for an electric locker. However, not sure who make one for a 9.5” Toyota diff.
Auburn Pro 546030 is listed for the 40 as far back as 1968, I’ve been wanting to put one in my rig for a while now….However, cost is quite a bit higher than a lunch box locker.

 

[77mustard40]

I have a Powertrax No-Slip in the rear of my 40, picked it up from a friend a number of years ago and its been great. Its a quiet cheaper lunchbox style locker, think Aussie on steroids. I get a click or bang once every month on two but otherwise its dead quiet and has better road manners than an Aussie. Off-road it just works, its there when needed without thinking about it. For $400 bucks and a couple hours to install its an option since you don't have to remove the carrier. If I was going to do it right, I agree with others that the new e-lockers like Harrop / Eaton are the way to go. Just adding this option to the discussion since I rarely see it mentioned.

No-Slip Traction System - PowerTrax

www.powertrax.com

 

[peesalot]

I tried one of those, installed properly, worked great , did the click/bang/unload on the street around corners which gets your attention, IMO the axle splines & side gears of a 9.5 carrier are not built to take the shock loading the lunch box lockers deliver. You can set them so tight they are basically a detroit or spool. Mine worked until I got to Rubicon, worked thru the trail but going out on Sunday it started clicking, was waiting for it to snap axle, roasted the splines on the axles, IMO they work, however if they start skipping or clicking too often or too easy get em out & reset with proper clearances cause when they start just skipping every slight turn they will just FUBAR the splines.

 

[FJBen]

The snow driving is really my only area of concern with a lunchbox/aussie locker in your case. Powder trails maybe not that much of an issue, but slicker situations could get sketchy. I don’t like the click/bang.

Personally I’ve had lock-rights, oem E-lockers and ARBs. I always vote for selectable lockers.

The ARB lockers/compressor in my current BJ74 have been there for at least 25 years. It’s still working. I’ve had this rig for 5 years and Ive only had to replace an oring on the compressor .99cents and then the front blue line as I broke it when pulling the engine.

Almost all of the arb complaints/failures come from poor installation. I had one fail(wouldn’t lock/blowing air) on an 80 series I bought used (didn’t install) Becuase bolts in the diff and pinion loosened up and pinched an Oring. Again install poor.



I’m not versed in the harrop but plenty to read on them vs ARB and which one is best for you.

 

[ryanwk628]

I'm going to be putting an Auburn LSD in mine, because I don't plan to have a tire in the air and want on road manners without having to think about turning something on or off. I think it would be fine for snow, sand and the occasional muddy track. Its the big boulders where the lockers are essential. Id love something like a Detroit Tru-Trac, we just put one in my buddy's Ford, but they do not make them for C clip axles.

 

[cstav86]

The added benefit of the ARB is onboard air. So if that is appealing or helpful, throw that in the list of "pros."
I went with the ARB and feel confident I made the right decision for my needs.

 

[bj70bc]

they make the eaton/harrop/detroit autolocker for the c-clip semi floaters

 

[franklin40]

i’ve driven an aussie in the snow and ice. you need some traction around corners to get the outside wheel to ratchet. on ice this doesn’t always happen and the back end will kick out real easy. it wouldn’t be my first choice for snow again. i also had mud tires that were terrible on ice so maybe that played into it. and definitely do not put one in the front!! i went arb on my 62 and really love being able to select it on or off. not saying arb is what i recommend but some sort of selectable locker is worth the extra to me.

 

[UZJ40]

I was a die hard ARB fan... had the lockers, twin compressor, fridge, tent, you name it...

Unfortunately, my rear locker started to leak. It would still stay engaged, but the compressor would cycle on/off and I could hear the hissing and feel the air coming out of my axle breather. I had paid a shop to install them as I wasn't experience in setting up gears. At the time, I chalked that up to a bad install, so no hard feelings toward ARB.

Since then, I've had direct experience with 3 other ARB locked vehicles. A buggy (rear only), an LS swapped 4Runner with 1 ton axles (front and rear), and a close friend's FJ40 (front and rear). Guess what, they ALL leaked. My friend with the 40 even sent his to a very well known and reputable Cruiser shop to do the install because I had told him I had bad luck with mine leaking.

I know they upgraded their design of the O-rings to the X style rather than the standard O ring. My 40, the buggy, and friend's 40 all had the newer style.

I will NOT use ARB lockers again. I will only be using OEM, Harrop, or Eaton based e lockers. So discouraging after paying so much money for a nice product and install only to hear a hissing noise inside of your axle housing.

 

[bj70bc]

common issue with the arb's (of course some never have an issue)
e lockers are a bit more reliable (but again with age the actuators become rusted, fouled, busted etc)
but the most reliable is a eaton/detroit autolocker, you just have to be able to live with the quirks

 

[peesalot]

IMO the arb is great have had 4 LC 9.5, all but 1 broke. never leaked tho. And to be fair to Lock Right in my above post my 40 is SOA on 37's with a V8 & 120:1 low so not necessarliy the equip, the use had a factor. I switched to ARB's that was 2001, they lived until I went to 38's, Maxxis Creepys and an LS, the 9.5 cross shaft & spider gears in the arb carrier just didnt live, so I went with a narrowed, offset, SF, 60 with ARB.
If you can find a good deal or afford it thats best IMO but have their limits use wise.
FWIW the maching on the lunch box lockers and the diff rate springs have made them better. I just dont like the way the squared teeth snap over each other under load, how many times can that happen before the surface is s***/slope worn out ? You can set em up so tight they become a full time locker. And the two halves slam separately on the cross shaft which IMO snap it at the retaining bolt.