1985 4runner Diff Lockers

[bjammin210]

Hello!

First time posting, and starting my first build. Just had a few questions in regards to locking diffs on my 1985 4runner(stock 22re, auto trans).

I definitely plan on locking the rear, whether I lock the front or not. If I go with just the rear, would an auto locker be sufficent?
I know some people complain about the banging sounds, but I have an auto rear in my '13 silverado and it doesn't bother me.

Would any expo member recommend locking both front and rear? If so I'm sure I'd want to go selectable up front. I was thinking Yukon zip locker because they are running a rebate this month, and I found one with a free ARB compressor.

Would you recommend going selectable front and rear?

Just want to get a feel for what other people are running before I drop a ton of money.

FYI, I do plan on doing some off-roading in this thing, but want it to be enjoyable to drive on the road as well.

Thanks!

-Ben

 

[Travis1963]

We have an 87 and 85 truck with Detroit in rear and no locker up front. My son has an 85 4runner with ARB front and rear. We have been to Ouray twice. Once with 85 and 87 and once with 85 truck and 4runner. The 2 trucks with just Detroit in rear are exceptional on the trails. I daily drive them and the rear only bangs 3 or 4 times a year. The 4runner is crazy competent off road. It can do more than the ones with just rear lockers but how often will a person really need front and rear locked. When my son has the 4runner aired down and locked it will climb with the best of them but he only used it a few times and it was nice to have. A person has to decide if it is worth the investment for a front locker. I want an ARB in the front of mine but cant justify the money since I have done Ouray twice without it. There is a school of thought out there that some say if you are smart patient and pick the right line you don't need a locker but I really like the Detroit rear locker. These trucks are very capable with or without a locker. Hope this helps. Enjoy the build. Travis.

 

[tanglefoot]

The '85 4runner here has a LockRight in the back. It works great and I forget it's there unless I think about it. I just wonder how it would work with an auto trans, going around the corners. With the manual, if it starts bucking, I just shove in the clutch to make it stop. I'm not sure just getting off the gas with an auto would stop the bucking...anyone? Also, I'm running extra heavy gear oil in back (something like 90W-140) and it really helps quiet down the clicking but in cold weather, it gels between the locker plates and can cause only one side to be powered at times. It works flawlessly when above about 30F. Also, on easier terrain, the auto locker doesn't tread as lightly. The inner tire scuffs up the ground around every powered turn, even under very light throttle.

If I were to start again, although I'm very satisfied with the LockRight, I would leave both diffs open. I don't really go where a locker is needed any more, and with the flexy solid axles, it would do everything I want to do these days. Open diffs have such nice manners. I could never justify the costs of selectable lockers, myself. I think I'd have the most fun finessing it around with open diffs these days.

 

[playhard]

Back in the 90's I had a Toyota truck with Detroits in both ends. It was not a daily driver but I did drive it on the road quite a bit. I would hear a pop from the rear end a time or two about once a year. it was not a big deal at all. I have a friend that had LockRights front and rear. They made more noise than the Detroits but not enough to be a problem. My current Jeep has a Detroit in the rear and an ARB in the front. Again, not a daily driver but I dive it a lot on the road. I get almost no noise out of the rear. We had no problems running Detroits and LockRights front and rear BUT we wheel in OK and AR where wheel spin and a lot of right foot is part of the game on most of the hard trail. On the other hand, when we went out to Moab it was awful! a 3 point turn for an open or ARB front end was a 20 point turn for us. So the question about locking both end would depend on what kind of trail you will be running. One locker in the rear end is still amazing compared to open at both ends. IMO, a selectable is always best for on road driving but a non-selectable locker is not as bad as you might think. Unless you do a lot of mud or really hard trails, a rear locker is probably enough.

 

[bjammin210]

Thank you both for your responses. I'm thinking of going auto in the rear and selectable up front. Yukon Zip lockers have a rebate right now, and I found one on Ebay that comes with a free ARB compressor! I just don't want to regear and be mad at myself for wanting a front locker down the road....

 

[Stoffregen Motorsports]

Selectable lockers are the only way to go. If you drive in the rain or snow, Detroit lockers (in the rear) can be actually very dangerous.

Have you thought about factory Toyota electric lockers? FJ80 front and Tacoma rear, can be had for about $300 each (used) and if you look hard enough, you can find factory ratios of 4.56 or even 4.88.

 

[mbrewer]

lock 'em both, but I'd avoid autolockers

If I was regearing I'd lock the front if I could afford it.
I don't plan to lock the front of my 2000 taco, but I also don't plan to regear.

In solid axle rigs some folks like to put a detroit auto-locker up front and go selectable in the rear. That way you get no change in normal road performance.
In an IFS rig though, putting a detroit up front is guaranteed to break something if you ever use the skinny pedal in 4 wheel with the wheel turned to the lock.

In anything not a pure trail rig I wouldn't consider auto in the rear, 'cause in my mind giving it juice is how you get out of trouble if you go in to a corner too hard, and I like to drive fast, pavement or smooth dirt (I'm not talking baja here). When I already screwed up and I'm trying to power out of it, the last thing I want is for the locker to kick in and make things even worse... ick. For an IFS rig, I'd go selectable on both axles, limited slip, or nothing.

But, that's my driving style, to each their own.

 

[austintaco]

ehhhhhhhh depends

I disagree. My 84 has a detroit locker in the rear and Lockrite up front. The previous owner put them in when he re geared to 4.88's. I have driven the truck on long road trips, Minneapolis to Austin, TX, driven it out and back to most of the best wheeling spots in Central TX, and trailered it to Moab for a week of wheeling. I have never once regretted that it has lockers in it and they have never bothered me while driving around town. When it's not torn down for repair or replacement of a component, I drive it everywhere with no complaints.
On my Tacoma, it has an ARB up front and the factory locker in the rear. The trucks have different road manners, but that has more to do with the suspension setups than locker choices.
If you want to drive my 84, let me know. I can meet you somewhere and you can see how they feel on the road or on the trail.

 

[Travis1963]

I agree with Austintaco. Detroit in rear of 2 of my Toyotas. Drove both from Tn. to Col. and back twice and daily drive both. Never an issue or felt any risk in 1000'S of miles. Just an opinion. You'll probably like any choice you make.

 

[OSV]

i grew up in the midwest, driving in the early to mid '70's, when limited slip rear ends were standard issue for fast cars... i'd never want to run an open axle in back in the snow, lockers are the way to go.

i've had detroits in the rear axles of two trucks, a '72 gmc and the current 4runner... it can get a little noisy, but the only real problem i've seen with the 4runner is possible increased tire wear, because it occasionally chirps the tires around sharp turns.

the detroit locker in the front axle of my 4runner does make turning a bigger deal, even with hydro assist, but for most trails i don't need the front locker, because i have a second trans case and a bunch of gearing, along with a twin stick setup, that lets me select any gearing combo i want in 2wd... not sure how all that would work out with an auto trans setup, but i've been to san antonio, it's kinda flat you may not need a locker in front for awhile.

i would suggest getting the later model turbo/v6 rear axle setup for your '85 when you add the locker, it's wider, you can build it out then just swap axles, use the chromoly axle shafts: http://home.4x4wire.com/erik/diffs/#rear

stock toyota front axle housings are notoriously weak, and they warp at the drop of a hat when welded... if you haven't been thru the front end of your truck, i'd suggest pulling it apart and upgrading some of the components, even if you don't put a locker up there... if the front axle shafts don't come out easily, the housing is probably bent, it would be good to know that early on.

building up these trucks can get complicated, you need to make your mind up early on about big decisions regarding tire size, gearing, and additional trans cases, or you'll end up having to do things twice... a lot of it will revolve around how hard you plan on pushing the truck, there are weak areas that need reinforcement, like the area around the steering box, and just in front of that, where the frame meets the crossmember.

 

[bjammin210]

Selectable lockers are the only way to go. If you drive in the rain or snow, Detroit lockers (in the rear) can be actually very dangerous.

Have you thought about factory Toyota electric lockers? FJ80 front and Tacoma rear, can be had for about $300 each (used) and if you look hard enough, you can find factory ratios of 4.56 or even 4.88.

Is it just a whole new third member that will work with my existing axles? I hadn't thought about that as an option.

 

[bjammin210]

I disagree. My 84 has a detroit locker in the rear and Lockrite up front. The previous owner put them in when he re geared to 4.88's. I have driven the truck on long road trips, Minneapolis to Austin, TX, driven it out and back to most of the best wheeling spots in Central TX, and trailered it to Moab for a week of wheeling. I have never once regretted that it has lockers in it and they have never bothered me while driving around town. When it's not torn down for repair or replacement of a component, I drive it everywhere with no complaints.
On my Tacoma, it has an ARB up front and the factory locker in the rear. The trucks have different road manners, but that has more to do with the suspension setups than locker choices.
If you want to drive my 84, let me know. I can meet you somewhere and you can see how they feel on the road or on the trail.

I'd love to give your 84 a go! It would be nice to save some money by going with autos F&R.


Also driving in the snow/ice is not really a concern with this vehicle. I live in Central Texas, and we don't know what that is.

 

[bjammin210]

i grew up in the midwest, driving in the early to mid '70's, when limited slip rear ends were standard issue for fast cars... i'd never want to run an open axle in back in the snow, lockers are the way to go.

i've had detroits in the rear axles of two trucks, a '72 gmc and the current 4runner... it can get a little noisy, but the only real problem i've seen with the 4runner is possible increased tire wear, because it occasionally chirps the tires around sharp turns.

the detroit locker in the front axle of my 4runner does make turning a bigger deal, even with hydro assist, but for most trails i don't need the front locker, because i have a second trans case and a bunch of gearing, along with a twin stick setup, that lets me select any gearing combo i want in 2wd... not sure how all that would work out with an auto trans setup, but i've been to san antonio, it's kinda flat you may not need a locker in front for awhile.

i would suggest getting the later model turbo/v6 rear axle setup for your '85 when you add the locker, it's wider, you can build it out then just swap axles, use the chromoly axle shafts: http://home.4x4wire.com/erik/diffs/#rear

stock toyota front axle housings are notoriously weak, and they warp at the drop of a hat when welded... if you haven't been thru the front end of your truck, i'd suggest pulling it apart and upgrading some of the components, even if you don't put a locker up there... if the front axle shafts don't come out easily, the housing is probably bent, it would be good to know that early on.

building up these trucks can get complicated, you need to make your mind up early on about big decisions regarding tire size, gearing, and additional trans cases, or you'll end up having to do things twice... a lot of it will revolve around how hard you plan on pushing the truck, there are weak areas that need reinforcement, like the area around the steering box, and just in front of that, where the frame meets the crossmember.

Haha yeah most of San Antonio is pretty flat, but there are some pretty decent off road parks in the area that I plan to hit up. I want to do the lockers when I re-gear so I don't have to go through that process twice. I ordered a Trail Gear lift as well, so that includes a bunch of parts to rebuild my front axle. When I get in there to do that install I'll be looking at making some additional upgrades. Not sure how big I want to go on tires, but if I go over 33s I plan on upgrading to chromoly axle shafts. Once I get it all broken down I'll look into the axle issue you mentioned. Thank you so much for your advice! I love this forum. I really don't plan on pushing it too hard, but my goal with this project is to build it once and build it right!

 

[austintaco]

If you are going with TG and you have not ordered your kit, I would go with the 3" springs. When you add the new front hanger you end up with additional lift there and with the longer shackle. If you are running 35's, its still a bit tall with their 4" springs. I just dropped down to 255/85/16's and its too much for a tall 33". I am taking out a leaf next week. I spoke with TG and they recommended taking out a leaf over buying 3" springs because they stated that the 3" springs will not settle as much as their 4" springs and mine have settled in already so I know what I'm working with.

 

[bjammin210]

I ordered 3 inch springs for the front and 4 inch for the rear so it doesn't go nose up if I'm carrying anything. Thanks for the advice!