Anyone running sb 31 spline axles in 9"?

[Num nuts]

ok to run sb 31 spline or upgrade to the bb ends. Plan on running 35's and pushing around 330 horsepower. I'm looking at superior axle 31 spline sb conv. axles.

 

[TexasBronco]

I am running stock 28 splines BB with 35's and 300 horses.... I would say for now just save up and upgrade to 31 or even 35 spline BB axle.

 

[SaddleUp]

There are a few here that do. I would recommend upgrading the housing as well. It just doesn't make a lot of sense to me to put larger axles in at the cost of running a smaller bearing at the end. (In order to fit the axle the bearing ID is larger while the OD is the same so it's even smaller than the stock small bearing)

 

[Steve]

I've run Moser 31 spline shafts in my SB 9" for several years now, doing the hardest trails/obstacles I can find (not to my wife's satisfaction I can tell you) and have had no problems whatsoever.

 

[broncow72]

I've been running SB 31 spline Superiors for a few years now in the So Cal desert. Not had an issue. Lots of sand-to-rock transitions under power. But I am puttin out a tad less hp, prolly closer to 275 on a cold day, at sea level.

 

[SC74]

28 spline chromolly will do the trick too. I have a friend with SB 9" and chromolly shafts running 38.5's with a 390 and has not broken one on the toughest of trails. He broke several stock 28 splines before spending the cash on chromolly and has convinced me that for the money that is the route I am going to take.

 

[mountainlivin]

I have 31sp dutchman axles on a SB and have abused them with no problems.

 

[SaddleUp]

28 spline chromolly will do the trick too. I have a friend with SB 9" and chromolly shafts running 38.5's with a 390 and has not broken one on the toughest of trails. He broke several stock 28 splines before spending the cash on chromolly and has convinced me that for the money that is the route I am going to take.

I ran 28 spline alloy's in mine with a Detroit Locker for several months without breaking them with 35" and 37" tires before I built the 35 spline rearend for it. The splines are still straight on the axles so they might live a long time. I was just being proactive by changing them because I jumped to larger tires with a shallow wheel offset. I wanted bigger bearings at the ends so I went overkill on it.

 

[Rustytruck]

Get what you can afford, you can always change the bearings later if you get a deal on a better housing. You just have to keep the same brake drum spacing. With what your planning to run it is far more important that you get alloy axles than what bearing you run. Now if your planning to run extremely fast all the time with a very heavy tire and wheel combination and maybe jumping your truck thats a whole other story. You have to watch out with rock crawling and compound low dual transfercases and lockers too. You wouldnt believe how many people are still running stock axles with 28 spline's and their 35 years old. If you cant drive senceable and have a yahoo attitude then go for the gusto. You really need to sitdown and think what you will be doing in the Bronco before you start spending cubic dollars. Personally if you want to spend money I would get the alloy axles with the small bearings and use the extra money to change the output shaft on the transfer case before i would concider changing the axle housing. But thats me and everyone has their own opinion.