Please Explain these specs?

[LibertyTC]

Have 04 Libby 3.7 Rocky Mountain Edition, from build sheet it states 3.73 Trac-Lok Differential is this really a locked diff?
Also What is Front Dana 30/186mm all about?
****** is 4spd 42RLE (command trac) Part time seems to work good, 4 lo in snow while pushing is good as well but wondering about if a locked rear end is better, if I do not have one...Help explain these specs please and Thanks in advance .
Tim.

 

[Corwyyn]

Trac-loc is a limited slip type of differential - not a full locker but better than nothing in certain situations. The Front Dana 30/186mm just means that the front diff is based on the Dana 30 design (but with an aluminum housing and other changes for the IFS setup) and the main gear ring is 186mm in diameter (just over 7 inches). I could be wrong on the meaning of the front diff info but that's OK, I've been wrong before

And welcome to the forum!

 

[LibertyTC]

Detroit Locker would be best for snow then?

Not into heavy wheeling, just lots of snow like 24 inches of it right now.
So I guess for Rocky Mountain Traveling (heavy snow conditions) best to change to a locker. Any recommendations, re a locker rear end and what is involved keeping the same casings or? Any help here appreciated. 3.73 gears have to stay the same or I guess I have to change the front as well?

 

[Dave]

Not into heavy wheeling, just lots of snow like 24 inches of it right now.
So I guess for Rocky Mountain Traveling (heavy snow conditions) best to change to a locker. Any recommendations, re a locker rear end and what is involved keeping the same casings or? Any help here appreciated. 3.73 gears have to stay the same or I guess I have to change the front as well?

You would be better off if you are not going off-road and just concerned about snow, to leave the trac-loc in the rear alone and put a DTT in the front. It will be better than a locker for your use. You wouldn't need to change gears.

Just my opinion for your usage.

Dave

 

[LibertyTC]

Dtt?

What is a DTT in the front?

 

[Jeepin05]

I believe it's a Detroit TrueTrac Limited Slip Diff

http://www.eaton.com/EatonCom/Produ...ducts/Differentials/DetroitTruetrac/index.htm

 

[LibertyTC]

DTT Ok But..

Now I am confused (that is easy 2 do) when it comes to Diffs. I found a link that explained: Detroit Truetrac 912A553 is a clutchless gear-based limited slip differential for the Chrysler 8.25" 29 spline axle.
There is a version for the Jeep Liberty's front D30a. As with any other limited slip device installed in the front differential, it will make steering slightly stiffer and cause the steering wheel to spring back to center more quickly than usual.

Ok ..but..why would I put a LSD in the front, is there not a locker in the front now? Then if I had a LSD in the front, I could drive in part time all the time, is that the benefit? Would it be better for grip in the snow than what I have now, is front not locked when in 4WD currently? What would happen with the new LSD when In Part time or 4hi/low would it automatically lock, or lock only when it starts to slip?? CONFUSED...explain please...Why would A DTT (LSD) be better than my current set up in the snow/ice?

 

[Corwyyn]

You're current setup is an LSD in the rear (Trac-Lok) and an open diff in the front. Jeep has never had an option (that I'm aware of) for any type of locking device in the D30a diff from the factory.

What the DTT would do is allow you to have better traction in slick/slippery conditions by allowing power to both front wheels once the LSD kicked in. It would NOT allow you to run 4WD at all times; you would still run the risk of ruining your transfer case if you tried running 4WD on dry pavement. In order to run 4wd all the time you would need a transfer case with the 'full-time' option.

 

[LibertyTC]

Thanks For explanation!

Thanks for that. That sounds beneficial, but expensive. Probably $2000+ parts/labor my guess here in Canada. Still not overly clear what is happening when I am in 4 low (does it work in reverse too) or Part time? SO with an open in the front what currently is happening in slippery conditions regarding the front wheels. The DTT would then lock both wheels or transfer the power to the slipping wheel, but what is it doing now?

 

[J-Thompson]

Thanks for that. That sounds beneficial, but expensive. Probably $2000+ parts/labor my guess here in Canada. Still not overly clear what is happening when I am in 4 low (does it work in reverse too) or Part time? SO with an open in the front what currently is happening in slippery conditions regarding the front wheels. The DTT would then lock both wheels or transfer the power to the slipping wheel, but what is it doing now?

the best way to under stand what is happening in your front diff is to have you go with some one who does NOT have any traction adding device in the rear
find some wet dirt or grass and have them go in 2wd
The out come will be "1 wheel peel"
this is what is happening in your front diff ,1 tire will spin and the other will sit still the 1 with less traction will spin
The thing that "locks" is the front and rear drive shafts
which then must turn at the same speed
this is why 4wd part time (high range) and 4wd low are bad in dry ground
4wd full time is fine

The reason it feels so different when in 4low is you are reducing your out put from 1 to 1 down to 2.72 to 1
or multiplying you out put power by 2.72

 

[tjkj2002]

Now I am confused (that is easy 2 do) when it comes to Diffs. I found a link that explained: Detroit Truetrac 912A553 is a clutchless gear-based limited slip differential for the Chrysler 8.25" 29 spline axle.
There is a version for the Jeep Liberty's front D30a. As with any other limited slip device installed in the front differential, it will make steering slightly stiffer and cause the steering wheel to spring back to center more quickly than usual.

Ok ..but..why would I put a LSD in the front, is there not a locker in the front now? Then if I had a LSD in the front, I could drive in part time all the time, is that the benefit? Would it be better for grip in the snow than what I have now, is front not locked when in 4WD currently? What would happen with the new LSD when In Part time or 4hi/low would it automatically lock, or lock only when it starts to slip?? CONFUSED...explain please...Why would A DTT (LSD) be better than my current set up in the snow/ice?

No locker or LSD was ever offered for the front D30A from the factory.

I ran the DTT in the D30A and a ARB locker in the 8.25,awesome comdo for a KJ,I wheeled the s$%t out of my KJ here in the mountains of CO with this combo and had far less problems then others,even one with ARB's F/R(but I had bigger tires).The great thing about the DTT is if you apply the brakes a little it will fool the DTT into "locking up" almost as good as a locker,and being gear based it will never wear out and no special additives needed.In 4wd the steering was a bit heavier and returned to center faster but I soon got used to it and never noticed it,in 2wd it is invisible.

 

[4Factor]

So to make this clear as mud and help a fellow out here, the front diff is open, the rear could be an LSD (depending on your options), but what is the center diff (when in Full-time). Based on what I've done with my KJ, I'm assuming the center diff is open as well (when in FT).
I did a U-turn in deep snow on a small path the front tires slipped off the path and I got stuck, front tires spun. Realizing I was mistakenly in FT, I switched to PT and backed up and finished the u-turn. So that's my experience telling me the center diff must also be open... correct me if I'm wrong.

Reason for the u-turn, someone got stuck and I had to go back. I then backed down the path and yanked him out. Looking back on it I shouldn't have attempted the u-turn, I should've just reversed, but all was fine in the end.

 

[tjkj2002]

So to make this clear as mud and help a fellow out here, the front diff is open, the rear could be an LSD (depending on your options), but what is the center diff (when in Full-time). Based on what I've done with my KJ, I'm assuming the center diff is open as well (when in FT).
I did a U-turn in deep snow on a small path the front tires slipped off the path and I got stuck, front tires spun. Realizing I was mistakenly in FT, I switched to PT and backed up and finished the u-turn. So that's my experience telling me the center diff must also be open... correct me if I'm wrong.

Reason for the u-turn, someone got stuck and I had to go back. I then backed down the path and yanked him out. Looking back on it I shouldn't have attempted the u-turn, I should've just reversed, but all was fine in the end.

The 242 select trac t-case has the full time option which is basically a "open diff" in your t-case that allows the F/R drive shafts to spin a different speeds making it okay to drive on dry/high traction surfaces without drive line damage.When in Part Time 4wd it locks the F/R driveshafts together so they spin the same speed all the time,and since your F/R diffs are slightly geared differently this will lead to major drive line bind on dry/high traction surfaces(that includes wet pavement),same goes for 4low.

Open diff = torque follows the path of least resistance
LSD = in therory the torque fllows the path of high resistance
Locker/spool = doesn't matter both wheels spin at the same speed all the time.

 

[LibertyTC]

Possible to install Full time from selec-trac?

Since my 04 does not have full time w/ selec-trac can the KJ be converted to full time somehow, is it feasible? What is involved instead of thinking about DTTs for front../Rear, which also would be expensive.

 

[Corwyyn]

Since my 04 does not have full time w/ selec-trac can the KJ be converted to full time somehow, is it feasible? What is involved instead of thinking about DTTs for front../Rear, which also would be expensive.

More expensive than lockers (even the full-blown e-lockers or ARB versions). You are looking at getting the selec-trac t-case, then IIRC you need to change the rear driveshaft since the selec-trac is longer than the command-trac (might have to change the front DS too?). Lots of other changes that will need to happen but I don't recall them right now.