WJ Knuckle Swap, trying a different approach

[asp]

Re: WJ Knuckle Swap... The CORRECT way!

It's been established that the purpose of the spacers is to align the ujoint axis to the ball joint axis.

Would running WJ stub shafts, WJ unit bearings, & WJ rotors work?

To the OP, Seal surfaces are usually about an inch wide, so spacing it out 1/4" (what the JKS spacer does) would (and did) work just fine for me.

 

[cal]

Re: WJ Knuckle Swap... The CORRECT way!

It's been established that the purpose of the spacers is to align the ujoint axis to the ball joint axis.

Would running WJ stub shafts, WJ unit bearings, & WJ rotors work?

To the OP, Seal surfaces are usually about an inch wide, so spacing it out 1/4" (what the JKS spacer does) would (and did) work just fine for me.

They would be the wrong bolt pattern, and IIRC WJ's used CV joints and not u-joints.

I have seen people run WJ unit bearings redrilled 5x5.5 and XJ stubs without the .250" flange spacer. The stub was not quite long enough and you could not put a cotter pin into the retainer hole and there was almost no meat outside of the wheel studs, but it did work.

 

[asp]

Re: WJ Knuckle Swap... The CORRECT way!

They would be the wrong bolt pattern, and IIRC WJ's used CV joints and not u-joints.

I have seen people run WJ unit bearings redrilled 5x5.5 and XJ stubs without the .250" flange spacer. The stub was not quite long enough and you could not put a cotter pin into the retainer hole and there was almost no meat outside of the wheel studs, but it did work.

:doh: I forgot about the bolt pattern mismatch... I sold my WJ'd 30 last winter and haven't touched a stock axle since. Thanks for the reminder. I, however, did not know that WJ's had CV joints, though it makes sense.

Neat info about that combo.

 

[cal]

Re: WJ Knuckle Swap... The CORRECT way!

:doh: I forgot about the bolt pattern mismatch... I sold my WJ'd 30 last winter and haven't touched a stock axle since. Thanks for the reminder. I, however, did not know that WJ's had CV joints, though it makes sense.

Neat info about that combo.

They may not be CV.. for some reason that is sticking in my head though.

 

[The Hard Struggler]

Re: WJ Knuckle Swap... The CORRECT way!

Look at those shafts. That will be an impressive 30. I'm curious about ball joint choice as well.

It is not a 30. The housing is a HP D44 from a 77 F-150, with welded wedges.


I think Tyler used the WJ inner Cs, to address the ball joint-axle shaft alignment, I may be wrong.

 

[cal]

Re: WJ Knuckle Swap... The CORRECT way!

It is not a 30. The housing is a HP D44 from a 77 F-150, with welded wedges.


I think Tyler used the WJ inner Cs, to address the ball joint-axle shaft alignment, I may be wrong.

It would not matter what the C's were - the distance from the retaining nut to the pivot plane is what will matter. The axle shaft is expecting an XJ knuckle, and you HAVE to accomodate it.

 

[The Hard Struggler]

Re: WJ Knuckle Swap... The CORRECT way!

Sounds reasonable, I don't know enough about the axle to say much more about it.

Tyler is a pretty sharp guy, if it can be figured out he can do it.

The RCVs are for a TJ Rubicon 44 if that makes any difference.

 

[cal]

Re: WJ Knuckle Swap... The CORRECT way!

Won't make a difference there, you have to accomodate for the 230 thousands somewhere (generally the .250" is considered 'close enough').

 

[Talyn]

Re: WJ Knuckle Swap... The CORRECT way!

Nice writeup, but as others have said the spacer is needed for a reason.

 

[Team Willys]

Re: WJ Knuckle Swap... The CORRECT way!

Nice writeup, but as others have said the spacer is needed for a reason.

Well what is it then?

The center line of the u-joint (or RCV in this case) is right where it needs to be. I did the measurements and from what I could tell, they are the same. If there was a difference it is definitely not a 1/4". The JKS spacer was designed with the late model guys in mind. You need it if you have the 00 or newer unit bearings or the rotor won't fit in the caliper bracket.

Now... all that being said, I haven't tried it with u-jointed shafts. But The RCV shouldn't be any different. The shaft didn't move forward or back when steered, which means the center line of the joint does indeed line up with the axis of rotation between the upper and lower ball joints. Also, think about it... the inner c's are the same between the WJ and XJ/TJ/YJ. Also, the stubs are the same, as well as the distance between the unit bearing mounting flange and where the axle meets the splines, so why would this cause the u-joint to be in the wrong place? It wouldn't. But just to satisfy those who still do not believe, I will be doing the swap on a u-jointed axle in a couple of weeks, and I will post up findings then.

So for those of you who disagree with me, you can do it you way and stack washers and hack it together unsafely. Not my ass in your rig when the rotor cracks and flys apart.

For those of you who have valid questions, I will do my best to answer them.

Ball Joints: Uppers are the same between WJ and XJ, lowers are WJ. The taper is a different angle according to Moog.

No this is not the LS2 XJ, he got Reid Racing Knuckles and is running REAL Dana 44 outer parts, not hybrid stuff like this. This was a custom housing that I built that is indeed TJ Rubicon width and used a High pinion Ford Center section, 1/2" wall 2.75" DOM axle tubes, and Jeep Dana 30 inner C's bored out to 2.75".

Like I said, I am doing another swap on a TJ Rubi housing that is still running stock shafts. It is in another XJ and he has the pre 98 unit bearings so basically the same setup we have here. If there is an issue I will let you know... but there wont be!

 

[Team Willys]

Re: WJ Knuckle Swap... The CORRECT way!

I have seen people run WJ unit bearings redrilled 5x5.5 and XJ stubs without the .250" flange spacer. The stub was not quite long enough and you could not put a cotter pin into the retainer hole and there was almost no meat outside of the wheel studs, but it did work.

Using a redrilled WJ bearing has no effect on u-joint alignment. The distance from the knuckle mounting surface on the unit bearing to where the axle shaft meets the unit bearing is identical on all 3 of the bearings. You can even see that in the first picture. You preach that I am wrong but you are contradicting yourself with this very statement.

 

[Destroyer]

Re: WJ Knuckle Swap... The CORRECT way!

Do me a favor when you do the next one and measure the distance between the ball joint centerline/stub shaft intersection to the unit bearing mounting surface on the WJ knuckle. I'd like to remove my deadly washers but for now it is the only solution that works.

 

[souske]

Re: WJ Knuckle Swap... The CORRECT way!

Is the fact that both the OP and WJ's are running CV type shafts the issue here?

CV's can suck up a little in/out movement. A u-joint type setup has nothing to give.

 

[Talyn]

Re: WJ Knuckle Swap... The CORRECT way!

Well what is it then?

Go back and read. It was already mentioned.

 

[ColoradoRaptor]

Re: WJ Knuckle Swap... The CORRECT way!

It would not matter what the C's were - the distance from the retaining nut to the pivot plane is what will matter. The axle shaft is expecting an XJ knuckle, and you HAVE to accomodate it.

Ding Ding Ding :worship:

As you can see, the flange height is exactly the same on the 98 Unit bearing and the WJ unit bearing.

I knew right away the correct way to do the swap... bolt the 98 unit bearing to the WJ Knuckle and then re-drill a WJ rotor to 5 on 4.5. No silly spacers or washer stacking required!

What does flange height have to do with needing a spacer??? Nothing!! :dunno:.......... your quote only relates to rotor/caliper alignment not u-joint/knuckle axis!

 

[jonzer12]

Re: WJ Knuckle Swap... The CORRECT way!

I have not seen an RCV shaft but if it is a typical ball and cage style CV they usually have some plunge to them. Completely different animal than a U-joint. That could be why you are getting away with not running the spacer.

 

[cal]

Re: WJ Knuckle Swap... The CORRECT way!

OP: You obviously have no interest in listening to people who have done this swap in the past (some of us several times)..

So good luck with it. Carry spare balljoints and stub's. And probably a spare unit bearing. eace:

To everyone else:

Don't do this at home. :gee:

 

[asp]

Re: WJ Knuckle Swap... The CORRECT way!

To the OP: Technology and common knowledge cannot advance without critics. The question about the spacing issue that Cal and I were discussing is very on-topic and a perfectly valid point of concern. A better way of allaying our concerns would have been to provide us with measurements that prove your configuration to be proper. Please try being a little less pretentious next time. Like Cal said, there are other people out there who might know a little something about what you're doing.

Edit: Against my better judgement, I'm going to write a little tech in this post too.

Also to the OP: You're right that the unit bearing mounting surface to the WMS is the same for both the WJ unit bearing and the 98 unit bearing. You have a picture that very clearly proves that. What cal and I are questioning is the distance between the ball joint axis to the unit bearing mounting surface. If that measurement is the same on a WJ knuckle and a XJ knuckle, your approach is valid. If that measurement is not the same (which I suspect that it's not), bring spares because it's going to: :explosion

 

[kastein]

Re: WJ Knuckle Swap... The CORRECT way!

I did look into running WJ stub shafts to deal with the fact that the bearing has a different thickness and offset from the back of the bearing to the u-joint centerline, and found the very same thing that cal and asp (I think, not going back to page 2) mentioned. They (WJs) run CVs. I considered trying to find a U-joint stub shaft that would be long enough to fit, but everyone in NAC fortunately told me to stop being a tard and spend the $42 on spacers so that I could use stock shafts/bearings as spares still.

There is a reason people do it the way they do... it results in the most stock part reuse in the most important places, i.e. where things may break or where custom parts are not easily fabbed or are expensive to buy. I have not yet addressed the caliper spacing issue, if I find that I need spacers I will be making them from flat stock instead of stacking up washers.

 

[EvanRigged]

Re: WJ Knuckle Swap... The CORRECT way!

Ok everybody, go back to the first pic. Yes the flange surface of the two units on the right are the same, BUT! Look at the difference from the table to the surface where they mount to the C's... that difference is the reason for the JKS spacer.