Topic: Larger spline shafts VS. R&P

[FourbangerYJ]

Looking for some input. The D44 have a 8.5 inch ring gear, not huge but not small either. But with the 5.38's the pinion is getting pretty small. With the 30 spline shafts I would think that it would be close in which would break first.

But what about going to a larger dia. shaft like the 33 or 35 spline? Do you think the R&P would be the weak link? I am tempted to go with the 33 spline shafts mostly because I like the Detroit and the 35 spline shafts a ARB is the only thing avail.

Another thought would be a 9 inch with 35 spline shafts.

[Bounty Hunter]

I run 5.38 with 36" TSL's and neither the pinion nor the stock axleshafts have been a problem.

[Jeffy]

Looking for some input. The D44 have a 8.5 inch ring gear, not huge but not small either. But with the 5.38's the pinion is getting pretty small. With the 30 spline shafts I would think that it would be close in which would break first.

But what about going to a larger dia. shaft like the 33 or 35 spline? Do you think the R&P would be the weak link? I am tempted to go with the 33 spline shafts mostly because I like the Detroit and the 35 spline shafts a ARB is the only thing avail.

Another thought would be a 9 inch with 35 spline shafts.

Running 5.38's in a D44 is pretty common so I wouldn't really worry about it.  I've heard of people running 5.89 in them as well.

If you're wanting to go stronger then stock shafts then go Alloy.  If you want to run 33 splines then you might as well go with a Ford 9 or Dana 60 as you are shifting the possability of breakage aeay from teh axle shafts to something else.  Optimally though you're weakest link should be the U-joints.

[FourbangerYJ]

Running 5.38's in a D44 is pretty common so I wouldn't really worry about it.  I've heard of people running 5.89 in them as well.

If you're wanting to go stronger then stock shafts then go Alloy.  If you want to run 33 splines then you might as well go with a Ford 9 or Dana 60 as you are shifting the possability of breakage aeay from teh axle shafts to something else.  Optimally though you're weakest link should be the U-joints.

I was mosly thinking the rear. I am pretty sure the my front is about as strong as I can make it without going to a D60.

I have Alloy shafts in the rear, so maybe it's fine. I guess I am paranoid about breaking a shaft. I am pretty easy on the throttle and don't let it bounce. Maybe a set of spare shafts would give me peace of mind.

I run 1310 joints, the axle end of the rear shaft if a 1330. I have spare D-shafts F&R.

I have heard that Currie Ent. does not recommend the 35 spline shafts with their HP 9 with the 8.8 gears because they have had lots of R&P failures with the larger shafts. I guess the smaller 31 spline shafts will twist a fair amount before failing and absorbs some of the shockload and helps keeps the R&P alive. While the larger shaft does not twist as much and the R&P fail before the shaft.