Topic: Truetracks and the D30

[95 Lowbuck]

I have a '95 Wrangler, 2.5 and a 5 speed.
My question is how well a Detroit Truetrac will work
with the D30 axle disconect. Will it still be operable,
or will it turn the drive shaft reguardless ?
If thats the case I will replace the two piece axle
with a one piece.
Will one from a XJ work and which year should I
be looking for.

[BlackYJ]

Because of the axle disconnect the truetrac will only work when in 4wd.  I am pretty certain any one-piece shaft will work from a XJ or TJ, but I would go with a TJ and replace both sides because you will get larger u-joints.  Just remember that you have to remove the shift fork from the disconnect.

Edit: A limited-slip will only work when power is delivered to it so regardless where you have a 1 or 2 piece axle setup, it will only work in 4wd.

[Jeffy]

Here's the scoop;  the True-Trac is a gear driver Limited Slip Differential.  It will bias up to 2.5:1.  You can get this number down by applying the brakes a little to slow the faster side down.

The True-Trac will work with the vacuum disconnect D30 and like all lockers and tight LSD's, will turn the front driveshaft when in 2wd.

The only real downside to the True-Trac is if you do a one-piece conversion.  You will fell the locker working even though it is in 2wd.  It will try to understeer when ever you try to turn.  So, it makes steering feel heavy and unresponsive.

[low output 2.5]

it souldn't be working unless power is given to  the driveshaft so why understeer  i was told my lockright would do the same but when it's in 2wd it drives fine once the locker un locks i run a 1 piece shaft........my buddie ran a true-trac in his 30 it was normal on road but sucked off-road never lock up completely unless he dogged the brakes or punched it  ... but it was fun to watch :D

[FourbangerYJ]

I run a Detroit softlocker in the front with one piece shafts. In 2WD you don't know it's there. No understeer, no sluggish unresponsive steering.

[Gearhead2.5]

Detroit Tru Trac comments ..........

I can't really comment on the Tru Trac / Dana 30 , But ........

My 88 YJ  has a Tru Trac in the front  Dana 44 w/ warn hubs

When the hubs are locked ,  the vehicle is in 2wd , being driven on pavement , you barely know it's there . In 4wd , there are no harsh steering characteristics.  It's as described in the marketing literature , smooth , quiet  , .... BUT....  it is a LSD , not a true locker , when the going gets tough and wheels are spinning , a tap of the brake pedal will transfer torque to the opposite wheel or some times both will spin .



My 94 YJ has a Tru Trac in the Dana 35c  rear.  

It works well , is quiet and smooth , it's NOT a full locker , so you can pretty much forget it's there .


Bottom line , a Tru Trac is a well built differential , works as it is described , has no clutches to wear out and does not require oil  additives / friction modifiers  ,      I like them  .

[Jeffy]

I run a Detroit softlocker in the front with one piece shafts. In 2WD you don't know it's there. No understeer, no sluggish unresponsive steering.

That's because a Detriot or any locker for that matter, will unlock when in a turn.  The True-Trac will work as long as one side turns.  It will allow the unlocked side to turn 2.5 times then will spin the whole diff.  Which is why the front driveshaft may need to be balanced.  Now if you remove the disconnect, the passenger side will turn as well.  This is where you'll see understeer as tries to bias power 1:1 to each from the front tires.

And as long as it's for a Dana 30, it will work in any Dana 30.

[BlackYJ]

Detroits, softlockers, aussie, etc. only lock when power it given to them, so when you coast around corners, they unlock, stomp on the gas and then will lock.

I am still not totally convinced that a lsd will cause the front driveshaft to turn on a disconnect d30.  My reason is the driver's side will obvious turn the driver's side spider gear but since the ring is not turning, would it just transfer rotation to the intermediate shaft, but turn it in the opposite direction, just as it does with an open diff.

[Jeffy]

Detroits, softlockers, aussie, etc. only lock when power it given to them, so when you coast around corners, they unlock, stomp on the gas and then will lock.

I am still not totally convinced that a lsd will cause the front driveshaft to turn on a disconnect d30.  My reason is the driver's side will obvious turn the driver's side spider gear but since the ring is not turning, would it just transfer rotation to the intermediate shaft, but turn it in the opposite direction, just as it does with an open diff.

Tell that to my driveshaft...  It's has to be a tight LSD.  Like I said before the True-Trac will only bias up to 2.5:1

[BlackYJ]

Thought about it some more and now I agree with you, Jeffy.

[Jeffy]

I have a nice shiny ring around my driveshaft when it was rubbing against my exhaust downpipe.  Every time I did a hard right the engine would lean from a broken mount and rub while in 2wd.  I knew it turned but never bothered to confirm it till it confirmed itself.

[95 Lowbuck]

I think my first question has been answered,
it will lock up and turn the drive shaft.
And I realize I would have to balance it having read tha FAQ.
I had a Truetrac in the front of my old Toyota
and liked the fact that it didn't lock up in turns on the trail.
But with some brakes applied it worked very well.
As for the axles, I have the high pinion D30.
It is also the later version where the wheel bearing assy.
unbolts with three bolts.
Does this mean I have the Bigger Axle U Joints?
Since all TJ's have the low pinion, and I think the carrier
is positioned different I don't think that would be an option
for the axles.
Would an axle from the same year XJ work?

[Jeffy]

You should have the 297x series U-joints which are used on the D44.  There are upgradeable Spicer U-joints available also.  Has nothing to do with the 3 bolt wheel bearing assembly, though.

Like I said before it does not matter if the LSD was used in a Standard or High-pinion.  They use the same carrier.  My True-Trac came out of Brad Kilby's TJ and now sits in my YJ.

[BlackYJ]

The only real difference between high and low pinion axle housings are the gears (reverse cut for high, standard for low) and the oiling system.  The carrier, axles, etc. are all the same.  You can use TJ shafts in a YJ if you want to get rid of the disconnect because they are the same as XJ shafts.

Now I have a very late YJ (built oct '95) and I am pretty sure I still have the 260x u-joints.

[FourbangerYJ]

Mine is a Oct. 95 as well. It came with the 297 joints. I sold them a few years ago when I went to alloy shafts.

Measure the caps and let us know what you come up with. I am pretty sure you have the 297's.