When I turned the hubs in on my pair of front rockwells that put the wheel mount flanges to just over 69.5" (as it should be) but the driveflanges are still at 86" or so (duh; they stay at a fixed width) This means that they will stick out past the tire...

Has any one thought about cutting an inch or so off the ends of the drive flanges and a corresponding amount off the stub shafts and then capping the flange with some steel...

I guess my main question is how much spline length do you need at the drive flange to be reasonably safe - With the huge coarse spline of the stubs shafts I would think it shound not be a huge issue; but then again a fine spline should have more surface area contact (right?)

I am shooting for a metal to metal trackwidth of 82" or 83" so if I lose 1.5" out of each flange I am there - right now the ends look like they have a freeze plug in them so 0.5" of the flange is used up by the plug so the main queston is can the flange afford to lose and inch of actual machined spline (plus I don't think the stub comes all the way to the end of the flange)

Or should I just shut up and bust out the grinder and see for myself :flipoff2:

Matt

What tires and rims are you running that put you less than 86" wide outside-outside??

I have some 20" military combat rims that look kinda like the 5 tons with a different locking ring - I am putting new 1/2" plate centers from John351c in them and the backspacing will be set neutral

The rims are 11" wide - so 69.5" plus 6" beyond the wms on each side (12" total) puts my total mounted rim width at 81.5" then add in the side wall of the tire which is 16"+/- across the tread putting the total track width at 85.5"+/- but the tire is flexible - the rim is not...

Here is the rim with a tire:

http://home.off-road.com/~wanderingwillys/xjpics/Buggy_Stuff/mounted_tire1.jpg

So the simple answer is deep backspacing and a flatfender body that is 42" wide at its widest point by the tires

Matt

I don't think you can do it. There isn't much/if any material that could be chopped off the driveflange...the only thing you could eliminate is the little circle on the end of the flange...but it looks cool and probably adds strength. The splines are directly behind that.

CJ

CJ - I was planning on chopping the stubs back as well as the flanges.

So the real answer is that no one knows if the stub splines can afford to lose any length off of the very end of the stub itself...

How much engagement is needed in a male-female splined connection? - I would think it is related to the thickness of the shaft (similar to how much engagement is needed in a threaded joint before you have no additional benefit to having additional threading)

I would think having spline length that is equal to the max diameter of the shaft would be the minimum - does anyone know the actual engineering / design criterial for splined connections?

Matt

I think this is a really bad idea. The metal these are made out of isn't top notch chromemoly and the splines are course and need all the strength they can get. plus there is only about an inch and a half of splines on the thing and they are supposed to fit into that cap. to take an inch and a half off would require cutting pretty much all of the splines off. Even if there was some splines left they would strip the first time they were under any stress. I am positive that this would be strait up booty fab! If you wanted to do it right. Machine the spindle down and make shorter hubs and stub shafts. I know it isn't cheap but it is the only way to do it right.

I have to agree with that. These old axles are not very strong. Just old cast metal really. The coarse splines are not very strong to begin with. If you shorten them, you really start raising the stress on each spline. Something is going to go :boom:

Don't forget that with most old military hardware, it may have 20 - 30 years of abuse on it before you get your hands on it. Same with most anything you get from a wrecking yard.

From what I have seen so far, the first thing to go on a Rockwell is the stub shaft. I would leave it alone. If you really want to go narrower try cutting the long side housing down and replacing it with a short side axle.

I agree with the abuse and material limiting factors - and probably will not shave them down other than smoothing the endcap so it do not get hung up on stuff... However I am still curious in an ideal world what is the rule on splined connections - spline length in relation to shaft diameter....

I am pretty much not going to shorten the housings because I will have to move all my link bracketry which just barely squeezes on the housing now...

What is the mode of failure with the stub shafts - IIRC they were breaking at the middle or the yoke end of the shaft not shattering of stripping the splines off???

I will get the thing up and running before worrying about this too much more - thanks

Matt