+1 I can do the same with mine, both the plowing and the lug nuts- sounds like you've been running a bad posi for a while....

 

A lockable LSD like that AAM seems ideal to me.

Truly the best of both worlds.

jh

 

My "posi" has never been "good" then, judging by your experience. Even when new, I could get stuck on wet grass spinning just a rear tire.

The thing you guys need to understand is that not all factory LSDs are the same. Some second gens have the Powr-Lok, which is perhaps the best, most aggressive LSD ever made.

But a lot of the factory LSDs (especially D80s) were equipped with the Trak Lok, which is far inferior and has very little "posi" action.

The Powr Lok can increase tq transfer based on wheel slippage. The more wheel slippage, the more it will send tq to the wheel with more traction. This is due to the "ramping" mechanism that increases clutch pressure as wheel slippage increases.

The Trak Lok on the other hand, has just a static breakaway clutch. It can't increase tq bias like the p-lok can. So the Trak-lok just lets you vary how aggressive the differential is all the time. The stiffer you set it up, the closer you get to a locker (with all the quirks and lack of smoothness). Setup very aggressively, it will scrub the tires everywhere. Because it can't adjust the tq bias, the diff will go from being too loose to too tight with varying conditions. It's basically the worst of all worlds.

So if you guys with earlier auto trans trucks are making comments to me based on YOUR powr-lok equipped diff, it's completely irrelevant to my situation with the Trak-lok.

To avoid complaints of whining and scrubbing, the factory sets up the Trak-loks VERY loose. It's well known that the factory setup stacks multiple plates and frictions on top of each other instead of alternating them as a typical clutch pack would be done-- all in the name of weakening the diff to where it's essentially an open differential. They wanted that level of smoothness, and they got it by weaking the LSD to where it's almost always slipping even at extremely light loading.

I could re-stack my factory LSD and make it more aggressive, but I'd have to remove the carrier to do that. If I'm taking out the carrier, I might as well replace the whole diff with a much better unit, since I'd have to redo the setup and replace the bearings and all that anyway.

Make sense?

Justin

 

I absolutely love my ARB's (front and rear).

A few reasons...

I can let my wife take my truck when it's icy out or deep snow and not worry about the rear end sliding out.

If you ever get in a situation where it's needed, just flip the two switches, and it's almost unstoppable...

And I've got an Onboard Air System now... for the same money as an ARB compressor you can find a Vliar 480C compressor and 5 gallon tank online.

Yes it is more money upfront going with an ARB, but it really is worth it every time you use it.

 

I agree the ARBs are great when locked up off road, but when switched off, they are just an open differential.

An ARB is as useless on dry pavement as is an open differential. You cannot really lock and unlock the diff for regular street driving and certainly you do not want to engage the diff when turning a corner. Apples to oranges comparasion for street vs off road IMHO.

A well functioning limited slip will keep both tires from spinning going around a corner on the street with the power on, but it will not allow the inside tire to just burn off (open diff), nor will it have the tires locked to each other like a spool.

A selectible differential that goes from limited slip to spool is what I would prefer for the rear axle for all conditions. An ARB works best in the front with the CAD.

I forgot, the Eaton 'Electrac' IS a TrueTrac that is a selectable locker just like the AAM unit--it's just not available in anything over a Dana 60 yet.

The Eaton 'E-Locker' is a selectible open/locked diff like the ARB, but is actuated by electricity vs air.

 

I don't disagree with what you are saying. I have a 93 mustang that has the ford factory limited slip, I stacked frictions and steels every other one and installed a F150 S spring in order to make it behave "more like" a locker. It's all a trade off, not enough pressure/friction and you will do the one wheel peel, too much pressure/friction and you will scrub tires going around a corner. Even a tame limited slip can cause both tires to spin if on a slippery road.

For my decision the driving on slippery roads aspect was the most important. I had a jeep CJ5 with a Ford 5.0 EFI in it that I drove to work everyday for a while with a locked rearend. In the wintertime, it was down right dangerous on the highway.

Short wheelbase + locked rearend + slick roads =

It is an open differential when turned off. There is no reason why you can't use it on pavement though. I don't know how many times I've hit the button prior to leaving a stoplight or intersection just to make sure it's still workin' (that's what I tell the wife anyways)

 

ok i just noticed you have a d80 rear in your truck hohn. i had the same problem with a dana 60 one time. i had a track-lok but thought it was a open diff. so i bought a pow-lock to replace what i thought was an open diff. i got it straight now i know why you hate it. pushing your e-brake a little works better than a trac-lok

 

You know, it sure looks like a free-spin hub conversion would help things out up front a TON.

With unlockable hubs, you could run a Powr-Lok or such up front with virtually no wear to the clutches until you were off-road (small portion of the time).

With the Dynatrac kit's optional 35 spline inner axles, you'd have a lot more options available up front because many differentials aren't available in the oddball 32 spline size.

So let's say a guy bites the bullet and does the freespin conversion with 35-spline inners. Now you can do something up front other than an ARB. You can now do an E-locker. You can do a Powr-Lok.

For me, it's looking like the "ultimate" setup would be TrueTracs front and rear with a freespin conversion up front. That way you get no driveline binding other than normal 4wd binding due to lack of t-case differentiation). You get better traction AND better mpg when in 2wd, while getting better traction in 4wd with locked hubs and the TT diff.

Such a setup would also handle well off-road, especially in snow, as you'd get none of the misbehavior associated with a locked axle.

Thoughts? The only downside I see is like most things: $$$$

 

i had a detroit tru-trac in the 60 in the front of my mud truck before i went to rockwells. it was strong it held up to 44'' boggers with 35 spline shafts. but locking hubs are a must.i converted it to full hydraulic steering to keep it under control. i would start with a tru trac in the rear. a front locker is hard core. i thought you wanted to get up your driveway when there was snow on half of it. your ideal axles would be good under a rock buggie.

 

Huh? A rock boggy with no lockers at all?

 

You make some good points but given the weight of these trucks, I seriously doubt the free spin kit would actually save any fuel due to less rotating mass. Don't remember the cost, but the kits are pricey I think...

 

It's not the rotating mass, it's the reduced driveline drag. I went a searched the old freespin threads and most guys reported a solid 2mpg, some more. You likely won't see it around town, but hwy it should certainly appear.

Cost for Dynatrac was $1800, EMS was $1200.

With the 32 spline D60 axles, the only option up front is an ARB-- period. If you want something else, you need to swap to 30 or 35 spline axles. If you're going to upgrade to 35 spline axles, why not do the freespin conversion and get them as part of the kit?

With the upgrade to 35 splines, you can now choose an E-locker, Powr-Lok, ARB, Detroit Locker, Powertrax Lock-right, TrueTrac, and thus you have a lot of options-- even the Electrac, which is the ultimate option.

I've read a bunch of reviews that say the TrueTrac is completely useable up front. Perhaps, then even a simple axle upgrade is worthwhile to run a better differential, even without a freespin kit??

Justin

 

i spent around $1200 total on my kit from EMS, i needed new rotors and barings so with the cost of all that it wasnt much more to go with the EMS kit, before i was getting around 19 to 20 on going around 65 now i get 23 mpg. you can say they wont help all u want but i did it and it helped a ton. now HOHN im not trying to tell you that your posi is good, im saying all you should need is a good posi, you say your you have trouble keeping one tire from spinning when you take off at an intersection. a locker in the off position wont help there unless your looking at the AAM. my vote is for that and u let us know how good it works, that is if it comes for these axles.

 

The TrueTrac is pretty much the same as the posi that comes on the AAM axles, from what I understand. This would pretty much do all I wanted.

My current LSD is so loose that it's essentially on open diff-- but even worse than an open diff because I have to replace the whole carrier and everything to upgrade.

At least with an open diff, you can drop in a powertrax or somesuch for less money than a full carrier replacement.

The Trak-lok really is the worst of all worlds. All the "function" of an open diff at higher upgrade cost. I paid a mere $150 for this option too! Wow, what a bargain.

I'm sorry I misunderstood what you were saying, BB85. I agree that a functional posi would work wonders. Sadly, I haven't had one on this truck yet, so I can't tell you how well it would work.

Hôhn

 

You are more than welcome to my POS open carrier if you want it, but I don't think a Powertrax would make you happy.

Save up your lunch money and buy something worthwhile. I'm still saving my pennies for those Mach 4s.