Okay I have just joined this site but have been building my runner for over a year. It had a sagging suspension and a weak motor... pretty used up. I am from a big block muscle car background (450 plus H.P. 69 charger RT with a Posi) and new to wheelin, got hooked on a trip to the Alpine loop.
When I found I could get a posi for the front and rear I thought that would be great -so I did. it seems not many people are running them-whats up?

Also what do you think of the runner so far?

 

is your 4runner welded front and rear??? from your picture sig it looks sick... do you have any links to more pics?????

welcome

p.s next time might wanna rethink your thread name!

 

Hey texcat, alot of guys on the forum here will say that any sort of limited-slip type differential is less-than-adequate offroad. Many people have the experience that when one wheel lifts the posi becomes useless. I think that for slow crawling a completely live axle is preferrable.

I, however, do have a limited slip in my front diff and like it. But I am not a really intense offroader...

 

BigT, Will post pics tomorrow if possible, sorry if I was not clear on my post. I have the Precision Power Brute clutch type posi front and rear.they have double the normal spring load to better transfer power to both wheels.

RustBucket,I will be doing mountain trails in Colorado in the summer and beaches in south Texas during the fall. Not a serious rock crawler.

 

Needs a wincher front bumper and tube/wrap rear bumper

 

I lincoln lock mine. just nice when you break an axle to still have one left.

steers like hammered owl @hit though, hard on axles.

 

I can't stand limited slips or posi traction devices.

Huge waste of money. Had one for a while, and hated it in everything except snowy pavement. Should have just left the diff open. It was completely useless offroad.

Now I have 2 arb's, and they work wonders.

 

I'm not a big fan of the Mopars, but let's see some pics of the Charger. I've got a 1970 Buick GS 455 for my "project car", with a Posi as well.

I'd say save up and get ARB, or electric locker. I have neither, but I am planning on getting one of the two.

 

I'm locked F/R. But read about break dragging for better posi trac offroad, but you'll need really low gears. ie ultimate duels

Good looking 4rnr.

 

brake biasing or "dragging" doesn't work at all. I would put my ebrake on FULL (mine was in the rear), and i would still have an open diff.

 

I always thought that would work.
It just sounds like in theory that could be a way to get
the other wheel spinning. Since the e-braked wheel now
has the greater opposing force, and the open diff
will take the path of least resistance.

 

I thought it would too, but it didn't.

Just my experience. Others have had great success. Figured the OP would like some feedback from both sides.

 

The precision gear Power Brute unlike other posi's has double the amount of spring tension on the clutch assembly they are alledged to transfer power more effectively than the other LSD's -see precisions explanation below.
"While similar to conventional differentials, limited slip type differentials add a friction medium to the assembly to maintain equal power to both axles even if one tire begins to slip. When load is applied to the differential, the friction plates are also loaded, causing a good positive power flow to both tires."
Has anyone had real world experience with this specific unit ( power Brute ) ??

 

Just talked to the tech department at PG they say that when you have one wheel off the ground you have at least 50% power transfer to the grounded wheel and that all the knocks on modern LSD's for off road are old wives tails.. so what about that ladies??

 

They can bloviate all they want.

It's BS. Detroit made the same argument to me with their gear style TruTrac. It was BS.

I'm not giving you an old wives tale, I'm giving you real world experience. That company is trying to sell you a product, do you honestly think they'd tell you it was bad?

Sounds like you have an attitude that is better aligned with pirate4x4. I'd check things out over there, as you don't seem to like the advice we have to offer.

 

On the contrary i like the advise you offer thats why I post over here. You are one opinion just like them but i value your opinion if you have used that specific product if not then you don't have a logical basis for your assesment.

 

Texcat, if you have posi's installed already I think you should find someone with a truck built up like yours but with either open diffs or with full lockers and see how they compare. Personally, I have always been really attracted to the theory of limited-slip diffs since they seem to be very adaptable to different terrain: able to be invisible on a surface with good traction and do their thing when traction is low. It's nice that it is self-contained too, rather than needing air compressors or electric motors (though I doubt those things are much of a hassle unless their fail on the trail).

Maybe with some concentrated effort you can end the debate and determine if a posi-type diff is useless, of marginal benefit, or of equal benefit offroad compared to a full locker.

 

I have a completely logical assessment.

An LSD is an LSD. Gears or clutches, they aren't full lockers. They do fine for mild offroading. When lifting a tire, its not going to work. If it did, a TON more people would run that brand, because LSD's are much better on road than auto lockers.

Go ahead and get it. If you can make it work, then more power to you. You know the risk that it may be pretty useless, and you know the benefit, that it might work just as well as a locker.

Good luck!

 

Since your original question was why more people don't use LSDs up front, that is the answer. When you get one wheel up in the air the other one stops helping. Seems like most of the toyota guys are rock crawlers and frequently get a wheel in the air. An ARB is the best of both worlds, open diff most of the time, fully locked when you need it, money is the limiting factor, as it always is. Otherwise I'd have a full tube chassis with a blown 351 and rockwells, but instead I have a rusted out, stock axled anemic snail on 31s

 

Yes the concept is very attractive if it works as i said in my sig line I have them "installed front and rear" and have put them to a limited test where they performed well. my question was more of why they are not more commonly used and i think ya'll have answered that very well. It appears that many people have had a bad experience with at least the older clutch type posi's what i am still to determine is if by doubling the spring tension thereby minimizing the slippage if PG has made the Brute Force an acceptable real world new alternative for moderate to heavy off road application. so more trail testing is next.. what a bummer.