Fino's D27 Knuckle Stud Project

Save yourself a couple bucks, I have 8 1.5” button heads for you.
Send me an address and I’ll put them in a bubble mailer. Then you might have 6 leftover for the next guy!

 

These are what I used, in have the box less the 12 i used already turned down. Any longer and they will likely interfere with the hub. Like other offers yours if you want them just send a destination.


20220226_190953 by Joe with a jeep, on Flickr

20220226_190455 by Joe with a jeep, on Flickr

 

James these are the lock nuts I had to use due to not much bolt sticking out.
https://www.boltdepot.com/Prevailing_torque_lock_nuts.aspx

 

Probably a dumb question, but why wouldn’t you use regular studs instead of buttonhead bolts? Wouldn’t studs solve the clearance problem and make the hole easier to machine since you would drill out the threads on purpose?

 

The idea is to use a bolt instead of relying on the weak threads in the cast iron steering knuckle.

 

This is how the newer Dana 30 is designed as well.

 

But a stud like a wheel stud also had a head on the backside. Wouldn’t that serve the same purpose? I’m thinking of the studs that are used in hubs.

 

The issue is the cast iron threads aren't fully utilized with the bolts and get pulled out. my plow jeep had several stripped so the knuckles had to get heli coiled by a machine shop and at that point you might as well have the inside faced and have peace of mind that the bolt head and all the threads would need to come out before you loose a wheel.

The big issue is when people swap brakes and the backing plate thickness takes away from the standard bolt engagement in the knuckle.

 

Those won't be as strong because it removes the existing threads and you need to be confident it won't spin or crack the iron casting.

 

I remember reading somewhere about doing the conversion this way.
2 issues, the studs required were some oddball unobtanium piece, and the knurls where they press into the knuckle create stress risers that can cause cracks. There's not a lot of material between the bolt holes and the center hole in the knuckle.

 

The button head screw solution is not new at all. That's exactly what my dad did to his Jeep back in the 70s.

 

This means the D30 does not have the thread pulling issue?
Just wondering if the Yellowjacket needs this mod or not.

 

No, it doesn't. Another reason to swap to Dana 30.
But I should back up, if you keep everything stock on your Dana 27, it should last a long time.

 

This is a dana 25/27 problem. The D30 is a better design.

 

Thanks fellas.

 

James, did you get to the front brakes yet? Just wondering what brake hoses to use on the for the disc conversion. Most particularly, what length as I believe you and I are both running about 2.5" lifts.

 

If it helps wheelie, i had my hoses for front discs on a D27 made to 18” with the calipers in about 9:30/3:30 positions. Pictured here.
http://www.earlycj5.com/xf_cj5/index.php?threads/153111/#post-1751480