Author Topic: YJ VS. TJ Dana 30  (Read 1531 times)

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Offline 95 Lowbuck

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YJ VS. TJ Dana 30
« on: June 17, 2007, 01:45:48 PM »
What is the difference between a 1995 YJ HP Dana 30 and a TJ LP Dana 30 ?
I know about the Pinoin location, and my HP Dana 30 has the Unit Bearings,
and the bigger Axle U-Joints. I also had my front DS straightened and balanced.
So I'm hearing that a Truetrac will work good in a TJ axle but not a YJ.
Something about the TJ having better bearings.
Does a TJ have a CV Driveshaft ?
1995 YJ RioGrand, 2.5, AX5, 231 T.C., A.A. SYE,
D30, XJ D44, Truetracs F+R, CV D.S. F+R, 4.88's
R.E. 4" STD., 33-10.50 BFG KO2's on stock rims.

Offline chardrc

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Re: YJ VS. TJ Dana 30
« Reply #1 on: June 17, 2007, 05:37:36 PM »
only difference i know of is that yj d30's have central axle disconnects, and i think they got rid of them for the tj's. not 100% sure but thats all i know
1990 YJ 4cly, ax5, 2.5 inch BDS lift, 31 MTr\'s,  Powertrax-lockers all around, track-bars removed, boomerang shackles, warn m8000 winch, electric fan. [sold but not forgotten]

2007 jk Rubicon 2dr

Offline Jeffy

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Re: YJ VS. TJ Dana 30
« Reply #2 on: June 17, 2007, 09:57:25 PM »
What is the difference between a 1995 YJ HP Dana 30 and a TJ LP Dana 30 ?
I know about the Pinoin location, and my HP Dana 30 has the Unit Bearings,
and the bigger Axle U-Joints. I also had my front DS straightened and balanced.
So I'm hearing that a Truetrac will work good in a TJ axle but not a YJ.
Something about the TJ having better bearings.
Does a TJ have a CV Driveshaft ?

HP is stronger then LP because of the cut of the gears.  The earlier 1987-1993 use a 260x series U-joint at the axles.  Later ones use 279x series which are a bit stronger.  The LP gears from the TJ use crush sleeves for the pinion bearing preload while the better setups use shims.  The disconnect on the YJ does add complexity to the mix which makes it weaker.  Not only the axle shafts but the housing too.  So which is better?  Neither, the XJ HP D30 is the strongest.  Although, I'd say the YJ has the edge when you swap some parts out.

Only ZJ D30's have CV joints but I would say they are a weakness since they are prone to damage.

I run a TrueTrac in my YJ D30.  There are some downsides but really it's not a big deal.  Because the LDS is gear driven, it not act like an open diff.  The LSD, like a Locker will cause your front driveshaft to rotate even when in 2wd.  YJ Driveshafts aren't balanced from the factory so you might need to balance it.  IF you remove the disconnect, you will encounter understeer.  That means when you make a turn, the Jeep will want to go straight.  It's just inherent to LSD's.  Love it or leave it.  A Locker will disconnect because inducing understeer so in that sense it's better.
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"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."