vetteboy said:
This is true...but...everytime I've seen a D30 break, it's been the u-joint, and everytime I've seen a D44 break, it's been the shaft itself (at the spline neckdown) or the yoke ears.
Given that they both run the same u-joint (at least some D30s), that sort of makes me have a little more faith in the D30 shafts. As sacreligious as that may sound, maybe the D30 shafts just have better transitions to get rid of stress risers or something.
You just haven't seen enough of them break. I've seen D30 u-joints break, stub shafts break, and quite a few inner shafts break. When using a 297x/760x axle u-joint, the joint is about as strong as the ears of the Spicer axle shaft yoke, and if the cups are secured with full circle clips (snap rings) or are tack welded to the ears, the u-joints are usually stronger than the Spicer yoke ears (D30 or D44). So, you will many times see the yoke ears sheared when the axle breaks.
A D30 with the larger axle u-joints can take quite a bit of abuse, but it's still not as strong as a D44 in every area other than the axle u-joints (if the D30 has the large joints). However, since the axle u-joint and axle yoke ears are the weakest link in both, I'd rather have a D30 with chomo shafts and snap ringed u-joints than a D44 with stock Spicer shafts. Since it's easy to buy D30 shafts with the larger u-joints (many drivetrain stores sell them new), and it's not hard to put snap rings on them, you could easily break as many axle joints with either a D44 or a D30 if running Spicer shafts. This is why most people swapping a D44 consider the expense of chromo shafts to just be a part of the swap. If you're willing to spend the money on chromo shafts for the D30, it can be a good way to go over the expense of a D44.....depending on how hard you use it, what terrain, and what tire size. The D30 housing is still subject to bending, and the ring and pinion prone to spitting teeth, if used with tires larger than 33's, however they can still hold up reasonably well to 35's with an easy driving style and chromo axles.
PapaPump said:
after reading some of these posts though i do have a question of my own, though. somebody mentioned that 95 and newer came with the 297s...if i wanted to be cheap, i should be able to get a junkyard d30 from a 95 or 96 4cyl then, and get high pinion, 297s and 4.10s, correct? or, if that was only the abs models...then that might be a rare option on 4cyl models.
Some one knows this for sure better than I do, I can't keep track of all the year differences, but I believe they all started coming with the larger u-joints in '97, and before that it was only if they had ABS. If you're poking through the wrecking yards, the 260x joint cups are 1 1/16" diameter and the 297x cups are 1 3/16" diameter. It's also easy, and relatively inexpensive, to just buy new Spicer shafts with the larger u-joints.