D30 vs D44 front axle

[ChrisD]

For you that didn't know, found some great info comparing the D30 vs D44.

U-Joints
Most Jeep YJ's came with the smaller Spicer 260 u-joint in the front axle shafts. It has an average torque rating of 2900 lbs-ft. A set of 35" tires will quickly break these, unless you are light on the throttle. Most every Dana 44 came with the larger Spicer 297 u-joint. With an average torque rating of 4400 lbs-ft, it is better suited for heavy use. Note: Late model YJ & TJ's ('97-and-later) have the larger Spicer 297 u-joint.

Shafts
There is a slight axle diameter increase between the Dana 30 and the Dana 44. The Dana 30 has a 27 spline / 1.16-inch diameter axle shaft, with an maximum torque rating of approximately 4100 lbs-ft. This "smaller" axle is best suited to 31 or 33 inch tire. The Dana 44 axle is 30 spline / 1.31-inch unit, with a maximum torque rating of approximately 6000 lbs-ft. This axle shaft is suited for 35 inch tires, and should handle the 36 or 37 inch tires.

R&P
The main area where the Dana 44 is stronger when compared to the Dana 30 is in the ring-and-pinion. The Dana 30's ring gear has a diameter of 7.2 inches, while the Dana 44 features a ring gear with a diameter of 8.5 inches.

So basically if I read this correct, the weakest point for both axles is the U-Joints with a torque rating of 4400 lbs-ft?

[beaker]

You could also eliminate the U-Joint with a set of these:

[ChrisD]

Hey Mike! How is the family?

I know a certain lucky person that might be picking up a set (not me).

[beaker]

Family's good, Mark's getting excited to go see Cars 2 opening night on his birthday.

BTW, keeping this on topic, 6800 FT/LBS to break those. And you break 'em, we'll replace them warrenty.

-mike

[nostaw]

Housing on a D30 is not as stout... Casting is lighter and the axle tubes use thinner walls / smaller diameter tube. Knuckles / C's / ball joints are smaller too.

I'm not trying to talk down the D30, but since you raised the topic...

Some of the D30 lockers have the option to support 30 spline inner shafts (I know ARB has an option) in an standard D30 housing.

JW

[johnsxj]

Housing on a D30 is not as stout... Casting is lighter and the axle tubes use thinner walls / smaller diameter tube. Knuckles / C's / ball joints are smaller too.

I'm not trying to talk down the D30, but since you raised the topic...

Some of the D30 lockers have the option to support 30 spline inner shafts (I know ARB has an option) in an standard D30 housing.

JW

True if you're not talking about the TJ D44's
The TJ D44 uses the same parts from the center section out as a TJ D30 in front and TJ D35 in the rear (axle tubes, ball joints, unit bearings, knuckles, brakes, brackets, etc...)

Both ARB and OX offer the 30 spline option for the D30.

[johnsxj]

CTM shafts are nice but the $$$ they cost!!!!!!!!!!!!

[beaker]

CTM shafts are nice but the $$$ they cost!!!!!!!!!!!!

Those are RCVs....

[johnsxj]

My bad but they're still major $$$$$$$$$$$$$$$$

[SidewaysTim]

You could also eliminate the U-Joint with a set of these:

I've been running these for a couple of years now and LOVE them. I have the 3rd set that RCV shipped. No steering feed back when the wheel is turned and they are just as strong with the wheels straight as they are at full lock. They are pricey but stronger than a u-jount shaft and the price is comparable to a top of the line set of shafts and u-joints.

[Frank]

Why would you be on your third set ???? Im still using my D-30 u-joints and carry both full replacements and have done some pretty challenging stuff on 35s . I think the driver has more to do with parts lasting than any chart. The weakest point of the u-joint is when under power and turned. Dont do it ! I have 86 knuckles and Im mot even sure the 297-X will fit through them. Id have to build the knuckle while inserting the axle, Thats a thought. FjR68

[johnsxj]

No Frank!!! He has the third set of shafts that the company sold!!!!!!!

[Frank]

OHHHH ? Sorry ! FjR68

[beaker]

I've been running these for a couple of years now and LOVE them. I have the 3rd set that RCV shipped. No steering feed back when the wheel is turned and they are just as strong with the wheels straight as they are at full lock. They are pricey but stronger than a u-jount shaft and the price is comparable to a top of the line set of shafts and u-joints.

Now I know what you mean about no feedback. I just pulled out of the garage, no front drive shaft, locker engaged to make sure it was working, expecting that feedback to tell me the front end was locked as I turned. None at all. Thought I might need an adjustment until I walk back & saw the grass chewed up from the locked wheel in the turn, ending right about where I unlocked it...


-mike