'78 FJ40 needs lockers. I need advice

[UncaMo]

I'm about to rebuild the knuckles and replace the hubs. I figure while I've got the front in the air I might as well install a locker. I've got some cash saved from VA disability and can afford the front locker now. A month or two down the road I'll do the rear. I'm "frugal." I'm looking at ARB and Eaton ELocker. I'm in NM and virtually all my wheeling is in sand and rock. I have to drive a considerable distance to get to where I like to wheel so I need selectable. Pros and cons of air vs. electric? I want onboard air anyway so that's not a concern if I go ARB.

 

[Grayscale]

I advise you to entertain the idea of doing the rear locker, first. Not that having two lockers is a bad goal, it is just that I know guys who report that it isn't necessary. They run more rocks than sand, but, it is the frozen trail that is where the traction control is needed. Imagine that you are in the rocks, and the front axle tires are inclined to roll forward, but, the rear axle is inclined to roll back, not having some slip somewhere is going to place stress on the transfercase akin to using 4wd on pavement, and the truck needs to slip for steering to navigate/turn tight, or uneven, spots of trail. Are you still running the stock transfercase? Plus, the birfields at angles has been a point of concern for many - I don't agree with the argument except that anything has opportunity for failure.

My first time out was a place that iirc they were calling "The Waterfall" - middle Rio Puerco drainage. Tons of sand, but we were headed for the rocks with Detroits front / back, SOA, and 35s. They were fine for the Interstate highway - it was fun to hear the clicking as we went thru intersections etc. But, nothing more trying on our patience than watching the owner's (assisted by someone who knows) axle shaft repair which was holding up a whole bunch of trucks getting back out of the slot canyon, and I didn't sleep too much last night because the desert in October all of a sudden got really cold.

Now, as far as sand goes, more traction the better. As far as tire psi goes, make the contact pattern conform as much as you can to whatever is below.

 

[MDH33]

I agree. I've run a lot of trails over the years in 40's and 60's and never needed more than a rear locker. Love the ARB air locker in my 60!

 

[sogncab]

Make sure to replace pinion and carrier bearings.
If the gears are tired replace those too. It's apart. Might as well.

If I were to do it over again, I'd source a full float rear axle as well. Probably overkill as my off-road trips will be pretty tame, but I like overkill. If you break the clip off of a semi float its much more challenging getting back to a trailer. Semi float, yank the axle shaft, engage the locker and you've still got one drive wheel on that axle yet.

I have my ARB lockers and compressor almost finished up. I would've been done a couple of weeks ago, but I converted to the newer style rear drums, and didn't quite have all of the parts. Should have it moving again today. I can't put the axles back in the tube until I get the brakes mounted. Or at least the backing plates mounted.

Only experience I have with an E locker is in my Ford pickup. It seems to be fast. I think I'd lean towards air for anything just because having a compressor with is realty nice.

Somebody more knowledgeable would have to weigh in on the pros and cons of each.

 

[pb4ugo]

You should put a locker in the rear 1st and a winch in the frt, it may be all you need. It's cheaper too. I 1st ran a lunchbox locker in the rear and the capabilities of the 40 were huge from an open rear end. Lunch boxes are noisy, and really effect driving characteristics and would not recommend one if you can afford something better. I eventually installed an actual Detroit Locker in the rear which is quiter and more refined and doesnt effect handling as much. I forget that it's in there, but the rear is still locked with its driving characteristics. If you like the way your 40 handles now, a selectable locker in the rear would be better. I later installed an ARB in the frt in the 90's, and really like it. It locks instantly. I wheel the 40 pretty hard, I find I use it maybe 5 or 10% of the time. If you install a locker in the frt you should install alloy or Longfields birfields. I didn't start breaking birfields until I installed a frt locker. Lockers make the axle want to go straight, so an engaged locker in the frt will be hard to turn without power steering. The frt locked will also push in the turns, because both wheels are spinning the same speed. My red 40 is more of a driver and will eventually be getting ARB'S, starting in the rear. Then the frt with alloy birfs.

 

[UncaMo]

I advise you to entertain the idea of doing the rear locker, first. Not that having two lockers is a bad goal, it is just that I know guys who report that it isn't necessary. They run more rocks than sand, but, it is the frozen trail that is where the traction control is needed. Imagine that you are in the rocks, and the front axle tires are inclined to roll forward, but, the rear axle is inclined to roll back, not having some slip somewhere is going to place stress on the transfercase akin to using 4wd on pavement, and the truck needs to slip for steering to navigate/turn tight, or uneven, spots of trail. Are you still running the stock transfercase? Plus, the birfields at angles has been a point of concern for many - I don't agree with the argument except that anything has opportunity for failure.

My first time out was a place that iirc they were calling "The Waterfall" - middle Rio Puerco drainage. Tons of sand, but we were headed for the rocks with Detroits front / back, SOA, and 35s. They were fine for the Interstate highway - it was fun to hear the clicking as we went thru intersections etc. But, nothing more trying on our patience than watching the owner's (assisted by someone who knows) axle shaft repair which was holding up a whole bunch of trucks getting back out of the slot canyon, and I didn't sleep too much last night because the desert in October all of a sudden got really cold.

Now, as far as sand goes, more traction the better. As far as tire psi goes, make the contact pattern conform as much as you can to whatever is below.

The only reason I plan on doing the front first is that I'll have the front axle torn apart already. I probably won't take her out wheeling hard until it warms up. Bikini top is not sufficient in January and February in Albuquerque! I'll have the rear locker in before I go hard.

 

[UncaMo]

You should put a locker in the rear 1st and a winch in the frt, it may be all you need. It's cheaper too. I 1st ran a lunchbox locker in the rear and the capabilities of the 40 were huge from an open rear end. Lunch boxes are noisy, and really effect driving characteristics and would not recommend one if you can afford something better. I eventually installed an actual Detroit Locker in the rear which is quiter and more refined and doesnt effect handling as much. I forget that it's in there, but the rear is still locked with its driving characteristics. If you like the way your 40 handles now, a selectable locker in the rear would be better. I later installed an ARB in the frt in the 90's, and really like it. It locks instantly. I wheel the 40 pretty hard, I find I use it maybe 5 or 10% of the time. If you install a locker in the frt you should install alloy or Longfields birfields. I didn't start breaking birfields until I installed a frt locker. Lockers make the axle want to go straight, so a locker in the frt will be hard to turn without power steering. The frt locked will also push in the turns, because both wheels are spinning the same speed. My red 40 is more of a driver and will eventually be getting ARB'S, starting in the rear. Then the frt with alloy birfs.

Thanks for the insight. Maybe I can get away with just the rear locker. I was only thinking about doing the front first because I'm doing the hubs and knuckles. So... back to the real question: Air or Electric? The cost is pretty similar. IIRC, a selectable locker in the front won't really affect steering when not engaged and with the hubs unlocked.

 

[UncaMo]

Thanks for the insight. Maybe I can get away with just the rear locker. I was only thinking about doing the front first because I'm doing the hubs and knuckles. So... back to the real question: Air or Electric? The cost is pretty similar. IIRC, a selectable locker in the front won't really affect steering when not engaged and with the hubs unlocked.

And I've already got the winch installed.

 

[pb4ugo]

Replacing a 3rd member doesn't mean you have to completely tear down the frt end again. Pull the lockout, rotor, spindle and slide the birf out. I've replace plenty of frt broken axles on the trail. It's not a big deal, especially if it has recently been serviced. I prefer ARB, but it's all in know. Mine is really old and have been told by ARB it's much weaker than their current design. ARB's product support is great and very knowledgeable. It will only have hard steering when the locker is engaged. A lot of folks don't realize how much harder it will be. I suspect you will be installing p/s in the future once a frt locker is installed in the frt.

 

[Downey]

I'd vote Auburn LSD for the front all day long. Also keep in mind, in many instances the front end gets more bite than the rear end due to engine weight, so LSD up front would help in those instances- - -think about it.

 

[lcwizard]

lockers are like winches. You'll probably be fine without, most of the time, but when you need them, you need them, front and rear. I busted a pinion in a rear
full float axle a couple miles in on the hole in the rock trail near Bullfrog marina. Being a full floater, I pulled the diff on the trail, pulled out the broken pinion, stuffed a rag in the pinion hole, and drove out. Had I not had a front locker, I never would have got back to the highway. I drove all the way back to PHX from southern utah
on the front diff. It paid for itself on one outing

 

[pb4ugo]

I don't like the uncertainty of LSD diff. I dony like waiting you the LSD to engage. When i need it locked, I want it locked.

I've always thought the purchase of a winch should be the 1st thing to buy. It will get you through any obstacle, regardless of tires, lift and lockers.

 

[UncaMo]

It hadn't occurred to me to put a different brand/type of locker in each axle. That's more food for thought. Now. Who sells lockers and gives a veteran discount?

 

[UncaMo]

I don't like the uncertainty of LSD diff. I dony like waiting you the LSD to engage. When you need it locked, I want it locked.

I've always thought the purchase of a winch should be the 1st thing to buy. It will get you through any obstacle, regardless of tires, lift and lockers.

I got a winch before I got the lift and 33s.

 

[EWheeler]

It hadn't occurred to me to put a different brand/type of locker in each axle. That's more food for thought. Now. Who sells lockers and gives a veteran discount?

ARB in rear and auto locker in the front (lock rite, aussie, etc). Auto lockers are cheap.

 

[UncaMo]

Looks like I can get an ARB rear locker and the compressor for under $1200 with the discount. I'll run it by the wife and prolly order it this weekend. Once I get that installed, I'll see if I really need the front locker. Thanks for all the positive feedback and advice. And no dickhead trolls!

 

[71cruiser71]

ARB in rear and auto locker in the front (lock rite, aussie, etc). Auto lockers are cheap.

How does the auto locker in the front affect normal driving and when in 4wd? I have a Detroit in the rear and don't really like it. So if I can move it up front then get something different for the rear

 

[pb4ugo]

How does the auto locker in the front affect normal driving and when in 4wd? I have a Detroit in the rear and don't really like it. So if I can move it up front then get something different for the rear

Imo, if you don't like it in the rear you'll hate it in thr frt. It will push in the turns and not turn as tight. It will be less nimble. I prefer a selectable locker in the frt.

 

[EWheeler]

How does the auto locker in the front affect normal driving and when in 4wd? I have a Detroit in the rear and don't really like it. So if I can move it up front then get something different for the rear

It wont affect normal driving because you should unlock your hubs. I would only use this configuration on rig that sees 4wd primarily on the trail rig. When youre on a budget, its probably almost a $2k difference in costs from and ARB to an autolocker given the installation costs of the ARB.

 

[EWheeler]

Looks like I can get an ARB rear locker and the compressor for under $1200 with the discount. I'll run it by the wife and prolly order it this weekend. Once I get that installed, I'll see if I really need the front locker. Thanks for all the positive feedback and advice. And no dickhead trolls!

You realize the ARB replaces the differential carrier, correct? You’ll need to remove the ring gear from old carrier, reinstall onto the ARB, and re-setup your ring and pinion. Just want to make sure you understand whats involved with the “install”