TrueTrac Limited Slip in the front?

[kennyv0826]

I've never driven an 80 with a LSD but I've driven a few other vehicles including one I owned.

If you get one, don't bother with anything besides a Detroit Truetrac. That is the only one IMO that is worth running off road. That said, if you plan on rockcrawling don't go with anything besides a selectable locker. Truetracs are great for trails and even mud but when you start lifting tires (ie rocks) you need a true locker for best results.

 

[alkaline747trio]

Nay, I'm doing 4.88's and an Aussie this winter. It's still gotta roll on 33's for the street untill I go off to college. 37's and 4.88s on the trail will work out well enough for me. If I do part-time, it will be with a 62 t-case, twin-stick instead of vacuum.

 

[kennyv0826]

Nay, sounds good...and is what I have gathered. This rig is gonna be trail only in the next 2 years, but everything has to be done with a budget. If the planned 37's are gonna explode this LSD and end up costing me more money, then I'll pass.

I ran a Truetrac in a Toyota mini front axle with 35's and 38.5's and never had a problem (and I beat the crap out of it). I did explode a rear one however but that was fine since it allowed me to repalce it with a locker.

As far as someone on here saying that Slee knows what's best for an 80 or anybody for that matter gimmie a break. He and all of us know what is best for OUR 80's (most of the time) since we know the kind of wheeling we do. Slee crawls rocks so a LSD would be worthless to him. Most of the people that say LSD's suck have never used one off road and especially never used a Truetrac.

Full time AWD....who cares??? That's why it's called a LIMITED slip diff. It operates with all the benifits of an open diff on the street and even trails with much better traction when it's needed. I never experienced anything other than total confidence and a lot of extra traction while driving with my front LSD. It just sucked when I got to rocks.

It is simply a matter of the type of wheeling someone does and for the average to moderate off roader it would work just fine, full time awd or not.

 

[Nay]

Nay, I'm doing 4.88's and an Aussie this winter. It's still gotta roll on 33's for the street untill I go off to college. 37's and 4.88s on the trail will work out well enough for me. If I do part-time, it will be with a 62 t-case, twin-stick instead of vacuum.

Sounds good. BTW, Tractech, who makes the Detroit locker and TrueTrac was purchased by Eaton a year ago. Eaton has a "traction" site at http://www.traction.eaton.com that doesn't even mention the old Tractech products. Not sure that means anything, but probably worth looking into for any interested people.

 

[alkaline747trio]

Rocks are where I'll be, so open or locked is the way to go. I'm just gonna hold out for an ARB.

 

[Nay]

Full time AWD....who cares???

You should care because you get all the positive road benefits with AWD

Open diffs suck

 

[kennyv0826]

You should care because you get all the positive road benefits with AWD

Open diffs suck

Hey Nay,

You must not have understood what I meant. There were several members talking about why you can't run a LSD in a full time awd for safety reasons and I was saying that it didn't matter. I had one in a previous wheeling rig that I ran on and off road, and I would run one on or off road today. In fact I have one in my street legal AWD race car amd it drives the same as an open diff under normal conditions but grabs when needed.

BTW, how do you like your F.O.R lift? I am putting one in my 80 this Thanksgiving. I'm gonna try the 4.5" springs. I hear you are the main reason behind the development of the kit. Kudos to you my friend!

 

[SUMOTOY]

More experiences with trutrac fronts.... Thought so.

Regarding blowing up a true trac. As a rule, the fronts applications rarely have problems, the rear or center applictions do. I spoke extensively to my bro-in law on this a couple years ago. He is one of the driveline engineers on the offroad truck program for GM. He went to all the races to gather data on the driveline.

His comments were exactly that jumps killed the torsen type diffs, in any location. The fronts would last the longest, because they were under the least stress in terms of torque (we both agreed that was a weight transfer thing). I really doubt that the front would break unless under a high speed/high torque jump.

The rear and center applications are a different story. What kills them is mixed mu under high torque with weight transfer. Pavement to slick to pavement or bog in sand.

That said, it's my understanding (no affiliation) that both Zexel-Gleason (Torsen) and Eaton (true trac) have both come out with stronger baskets for the helix gears. I have no experience with these, but the torque hit is supposed to be almost double the older units. I still doubt they fly well.

ST

 

[bfly]

I've done a lot of wheeling, rocks and otherwise.

I think we have a new Crawford!

There is always one of these guys on every list. What would a list be without an armchair expert.

 

[Nay]

Hey Nay,

You must not have understood what I meant. There were several members talking about why you can't run a LSD in a full time awd for safety reasons and I was saying that it didn't matter. I had one in a previous wheeling rig that I ran on and off road, and I would run one on or off road today. In fact I have one in my street legal AWD race car amd it drives the same as an open diff under normal conditions but grabs when needed.

BTW, how do you like your F.O.R lift? I am putting one in my 80 this Thanksgiving. I'm gonna try the 4.5" springs. I hear you are the main reason behind the development of the kit. Kudos to you my friend!

I understood and was just loading some extra dung on the pile . They are absolutely sweet on the street, better all weather diff than open for sure. Heck, I built an Ford Dana 44 on my old XJ and put a True Trac in it to keep the incredible winter performance with my AWD setup and Detroit rear. It generally went everywhere I wanted, but a front locker makes all the difference in the world for a rig as big as the 80 because you tend to drag enough to need the extra pull to get through certain spots.

I love my setup - it is exactly what we set out to build: a premium upgrade to OME without an entire class increase in cost that runs 35's cleanly with a balanced travel suspension. I think you will be extremely pleased with these springs plus the Bistein 5100's, presuming you are going with Bilsteins. Those 4.5" springs were supposed to be the "heavy" version, amazing how a couple of spring versions can get you into the big time scope creep . You gotta do 37's on those springs because the 35's are just perfect on the 3.5". Keep us posted!

Nay

 

[kennyv0826]

I understood and was just loading some extra dung on the pile . They are absolutely sweet on the street, better all weather diff than open for sure. Heck, I built an Ford Dana 44 on my old XJ and put a True Trac in it to keep the incredible winter performance with my AWD setup and Detroit rear. It generally went everywhere I wanted, but a front locker makes all the difference in the world for a rig as big as the 80 because you tend to drag enough to need the extra pull to get through certain spots.

I love my setup - it is exactly what we set out to build: a premium upgrade to OME without an entire class increase in cost that runs 35's cleanly with a balanced travel suspension. I think you will be extremely pleased with these springs plus the Bistein 5100's, presuming you are going with Bilsteins. Those 4.5" springs were supposed to be the "heavy" version, amazing how a couple of spring versions can get you into the big time scope creep . You gotta do 37's on those springs because the 35's are just perfect on the 3.5". Keep us posted!

Nay

Ahhh.....I see said the blind man as he picked up his hammer and saw. Glad to hear you share the same opinion as me on LSD's up front. I think it just takes driving one to really appreciate it.

Also glad to see how much you like Frankies lift. I can't tell you how excited I am to get it installed and tester out. And yes, I will be running 37's. I got a steal of a deal on a set of 37x13.50 Toyo MT's so I figured I would try em out. I still havent decided on a wheel yet though. What b.s do you suggest? I found a good deal on a set of 17x10's w 4.5 b.s. but I didn't know if that was enough? Let me know what ya think.

 

[Nay]

Ahhh.....I see said the blind man as he picked up his hammer and saw. Glad to hear you share the same opinion as me on LSD's up front. I think it just takes driving one to really appreciate it.

Also glad to see how much you like Frankies lift. I can't tell you how excited I am to get it installed and tester out. And yes, I will be running 37's. I got a steal of a deal on a set of 37x13.50 Toyo MT's so I figured I would try em out. I still havent decided on a wheel yet though. What b.s do you suggest? I found a good deal on a set of 17x10's w 4.5 b.s. but I didn't know if that was enough? Let me know what ya think.

I'm not any kind of authority on backspacing on an 80, but I think you want an inch less than stock since most people use the stock wheels with 1" to 1.25" spacers. So if stock is 4.75" go for 3.5" - 3.75".

Nay

 

[kennyv0826]

I'm not any kind of authority on backspacing on an 80, but I think you want an inch less than stock since most people use the stock wheels with 1" to 1.25" spacers. So if stock is 4.75" go for 3.5" - 3.75".

Nay

Thats what I was afraid of. I quess I could still get those wheels but just use some 1" spacers with them.

Thanks for the advice.

 

[Nay]

Thats what I was afraid of. I quess I could still get those wheels but just use some 1" spacers with them.

Thanks for the advice.

1" spacers are too thin unless you have indents in the wheel for the part of the lugs that will extend past the spacer - the stock wheels have this. You'd need 1.25", and yes, you could do that, although I'd personally much rather just have the lower backspaced wheel if you can find one.

 

[kennyv0826]

1" spacers are too thin unless you have indents in the wheel for the part of the lugs that will extend past the spacer - the stock wheels have this. You'd need 1.25", and yes, you could do that, although I'd personally much rather just have the lower backspaced wheel if you can find one.

OK, well that is something I didnt know. 1.25" spacers it is.

Nobody has a 17" wheel with less than 4.5" b.s. (unless I want to spend $400 a wheel and go with Welds or Centerlines). If I could fit a 15" rim over my rear brakes then I have some options but that isn't gonna happen.

If you know of any rims in a 17" diameter with 3.5-3.75" bs for $200 or less each please let me know. Other wise I'll order the ones I found and get some spacers. Scratch that, the ones I want are back ordered but there is another set I found for a little more cash that are in stock.

 

[619TOY]

I realize I'm probably just stirring up the hornets nest but what the hell. First let me say that everything I say is based on first hand experience, not speculation. I think it would be unfair to say that a true trac is either the best or worst solution for the front of an 80. I have driven and ridden in an 80 with one. It is definately an improvement over an open front diff.

My DD 4Runner has one in the rear and to say that it is 80% locked would not be an overstatement IMO. If I ever give it slightly more gas than necessary around a turn it will squeel like a spool. That's why I chose it, for no brainer, always there street traction.

As far as the front end of an 80 is concerned, I've been wheeling in many surfaces other than boulders (not too many in AK) with a True Track in the front. In any type of dirt,mud,etc. it works great. I've also has the dis-pleasure of driving in snow, terrifying for me as an 80 will refuse to turn. However one of my best friends used that setup as his DD for years and loves the True Track front end, still the same 80 in the same AK snow and ice. To this day he still praises it for it's strengths.

Now he has an ARB in the front and has told me that it is noticibly more capable than the True Track. I think that goes without saying.But the dis-advantage is that now it's an all or nothing situation. It's not always there to give a little asistance. You decide when you want it then turn it on, then turn it off. Not an inconvenience but not a no brainer either. If the ARB is like my factory lockers, you've got to stop, lock them in then go again, then reverse the procedure.

In conclusion, everyone needs to weigh out the plus' and minus' for their own needs. I chose factory lockers for my LX and the True Trac for my DD 4Runner and both decisions are perfect. (actually my LX is my DD recently)

 

[kennyv0826]

619 Toy makes some good points. LSD's are better than an open diff however not as capable as a fully locked front end, but still manage to work quite well in a variety of situations (hardcore rock crawling aside).

The reason I think the Truetrac is the best LSD is because it uses gears instead of clutches and they never wear out and have proven themselves to be more reliable and provide consistent performance where as clutch type LSD's tend to be less reliable especially off road. This is not my opinion but the opinion of the many people that have done numerous tests with these types of LSD's. On road is a whole different story and a clutch type LSD can be adjusted to the drivers preferences and may provide better performance in certain low traction situations. But in the end, gear type LSD's will out last the adjustable clutch LSD's everytime.

 

[SUMOTOY]

619 Toy makes some good points. LSD's are better than an open diff however not as capable as a fully locked front end, but still manage to work quite well in a variety of situations (hardcore rock crawling aside).

The reason I think the Truetrac is the best LSD is because it uses gears instead of clutches and they never wear out and have proven themselves to be more reliable and provide consistent performance where as clutch type LSD's tend to be less reliable especially off road. This is not my opinion but the opinion of the many people that have done numerous tests with these types of LSD's. On road is a whole different story and a clutch type LSD can be adjusted to the drivers preferences and may provide better performance in certain low traction situations. But in the end, gear type LSD's will out last the adjustable clutch LSD's everytime.

The bigger problem with clutches and autolockers in the front, support Spikes theory of dangerous vehicle dynamics. The problem with a *front* autolocker or clutch is that you don't want it to go from open to locked (or max TBR) suddenly mid turn, and both these LSD require spin to be present to 'lock'. The nice thing about the torsen type True Trac is that it's torque allocation is linear to applied torque and slip, and all torque allocation change is complete by the time you have any wheel 'spin' present.

A true trac on a later 80 with the HF2AV (CDL off) will most likely exibit different turning behaviors than a non VC equipped 80.

ST

 

[kennyv0826]

The bigger problem with clutches and autolockers in the front, support Spikes theory of dangerous vehicle dynamics. The problem with a *front* autolocker or clutch is that you don't want it to go from open to locked (or max TBR) suddenly mid turn, and both these LSD require spin to be present to 'lock'. The nice thing about the torsen type True Trac is that it's torque allocation is linear to applied torque and slip, and all torque allocation change is complete by the time you have any wheel 'spin' present.

A true trac on a later 80 with the HF2AV (CDL off) will most likely exibit different turning behaviors than a non VC equipped 80.

ST

I've never heard of any situation where this has happend with a Truetrac (locking in mid-turn). It is not an auto locker it's a LSD and they never achieve full lock under any circumstances. They are very predicatable and I've never had a problem with one in any of the vehicles I've driven including my own.

An auto locker is a whole nother story and I would never say that it couldn't happen with one of these. That's why I would never suggest putting one in the front of a full time awd like the 80 series. You just never know for sure if it is gonna lock up in a situation that it shouldn't.

 

[kennyv0826]

One more thing. There are several production vehicles that come with front LSD's from the factory. Including the Acura TL 6spd, Mitsubishi EVO MR 6spd, Subaru WRX STI, Honda Civic SI, and even the piece of crap Dodge Neon turbo (although it's fast) plus a few more. There has not been a single negative incedent related to the front LSD.

The old Audi 4000 Quattros used to come with selectable lockers, but they eliminated that in 86. I think it had something to do with rally racing and they needed to have it on production vehicles in order to keep it in thier race cars. Those cars had amazing traction and were so much fun to drive.