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Knuckle stud upgrade

Printed From: The CJ2A Page
Category: CJ-2A Discussion Area
Forum Name: Modifications from original
Forum Description: Show off what mods you can do to a CJ-2A or questions about mods.
URL: https://www.thecj2apage.com/forums/forum_posts.asp?TID=46350
Printed Date: 28 Mar. 2024 at 11:40am
Software Version: Web Wiz Forums 12.06 - http://www.webwizforums.com


Topic: Knuckle stud upgrade
Posted By: jeeper50
Subject: Knuckle stud upgrade
Date Posted: 20 Jan. 2020 at 10:25pm
With Stan's recent knuckle stud problem I began researching info about this upgrade to our steering knuckles. I found some info over on the ECJ5 forum.  It replaces the studs with 3/8-24 button head cap screws to keep the studs from pulling the threads out of the knuckle. No pics but good info none the less. Requires you to clearance the new button head bolts for gouging the sealing surface of the knuckle, as if they never leak Ouch

http://www.earlycj5.com/xf_cj5/index.php?threads/knuckle-studs-again.112140/" rel="nofollow - http://www.earlycj5.com/xf_cj5/index.php?threads/knuckle-studs-again.112140/


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Belleview ol skool winch soon.
'48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers

Texan at heart,Alabama by retirement




Replies:
Posted By: SE Kansas 46 CJ-2A
Date Posted: 20 Jan. 2020 at 11:05pm
Message deleted

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46 CJ-2A #64462 "Ol' Red" (bought April 1969)(second owner)(12 V, 11" brakes, M-38 frame, MD Juan tub)

U.S. Coast Guard Chief Petty Officer(ret.)
U.S. Army Vietnam veteran and damned proud of it.





Posted By: 44bz
Date Posted: 21 Jan. 2020 at 1:13am
I did this upgrade on my J2000 and am about to do it on the 2a since I'm upgrading to discs.  Just ordered those studs actually.

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46 CJ2a - Buick 225, T90/D18, Warn overdrive, Rancho 2.5", power steering, disc brakes, 33x10.50 BFG KM3s

1968 J2000 - AMC 327, T18, Dana 20

1971 CJ5 RenI - 225, T18, D20(2.46:1)


Posted By: Mark W.
Date Posted: 21 Jan. 2020 at 1:23am
Keep in mind there are no Grade 8 button head bolts in US threads Least not that months of searching on my part could turn up. To get real strong Button Head Bolts for my Roll Bar mounting plates I had to bite the bullet and go with Grade 10.9 Metric. I used 8mm to replace the 3/8" bolts I wanted to use. Luckily I found this out before drilling holes so I could have them match the Bolt Diameter. 


Std Grade 5 Hex Head bolt              120,000 psi tensile strenght
Std. Grade 8 Hex Head bolt             150,000    "       "              "
High strength Socket Head bolt     170,000    "       "              "
Std Button Head Bolt  Alloy             120,000    "       "              "
18-8 Button Head Bolt Stainless       70,000     "       "              "     HALF AS STRONG AS GRADE 8   
316  Button Head Bolt Stainless       70,000     "       "              "     HALF AS STRONG AS GRADE 8 

Grade 10.9    Hex Head bolt             150,000        "       "              "

Just some food for thought


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Chug A Lug
1948 2A Body Customized
1949 3A W/S
1957 CJ5 Frame Modified
Late 50's 134L 9.25"clutch T90A D18 (1.25") D44/30 flanged E-Locker D25 5.38 Since 1962


Posted By: 64CJ5
Date Posted: 21 Jan. 2020 at 1:44am
I got my info on this up grade from the Jeep CJ rebuilder's Manual 1946-1971 By Moses Ludel.  I did the up grade on my 1964 CJ5 with the model 27 axle. 


-------------
64CJ5 "Eeyore"
01TJ "Tigger"
52 M38 Severely demilitarized, "Popeye" The Coast Guard Jeep.
14 JK "Jake"
To Trust Government Defys Both History and Reason.

PUBLIC LAND Owner/User


Posted By: unclemoak
Date Posted: 21 Jan. 2020 at 3:51am
Just ordered a piloted counter bore and button head bolts from McMaster to try this on a spare set of knuckles. Should have everything on Wednesday. 


Posted By: Ol' Unreliable
Date Posted: 21 Jan. 2020 at 5:51am
I did this to Ol' Unreliable about 15 years ago.  I made a mistake in not grinding clearance for the button heads when the knuckles go to turning limit.  I just adjusted the steering stops but now I have a much larger turning radius than I would prefer.  I can still get kuh-nuckle kuh-nock (with Rzeppa joints), so maybe I need to adjust the stops out more.


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There's a reason it's called Ol' Unreliable


Posted By: jeeper50
Date Posted: 21 Jan. 2020 at 1:32pm
Originally posted by unclemoak unclemoak wrote:

Just ordered a piloted counter bore and button head bolts from McMaster to try this on a spare set of knuckles. Should have everything on Wednesday. 

Post pics of tooling and your progress on those knuckles 


-------------

Belleview ol skool winch soon.
'48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers

Texan at heart,Alabama by retirement



Posted By: unclemoak
Date Posted: 21 Jan. 2020 at 2:05pm
Originally posted by jeeper50 jeeper50 wrote:

Originally posted by unclemoak unclemoak wrote:

Just ordered a piloted counter bore and button head bolts from McMaster to try this on a spare set of knuckles. Should have everything on Wednesday. 

Post pics of tooling and your progress on those knuckles 

Will do. I was planning to do a small write up and video.


Posted By: Spinnas
Date Posted: 21 Jan. 2020 at 2:20pm
Interested to see this. I have contemplated going to “D44” knurled spindle studs.


Posted By: wheelie
Date Posted: 21 Jan. 2020 at 11:27pm
I have s few pictures of mine somewhere. I'll try to find and post them.




Posted By: oldtime
Date Posted: 22 Jan. 2020 at 3:26pm
Here's mine I did a couple years back along with the double knuckle modification.
Casting cuts very easy so I just  milled the flat area by hand on a drill press.



-------------
Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963)
Zero aftermarket parts



Posted By: jeeper50
Date Posted: 22 Jan. 2020 at 4:20pm
Great pics, what is the P/N for those bolts spot facer if you still have them.

-------------

Belleview ol skool winch soon.
'48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers

Texan at heart,Alabama by retirement



Posted By: unclemoak
Date Posted: 23 Jan. 2020 at 12:17am
Originally posted by jeeper50 jeeper50 wrote:

Great pics, what is the P/N for those bolts spot facer if you still have them.

Here are the numbers from McMaster 
 

https://www.mcmaster.com/#3102A25" rel="nofollow - 3102A25  - High-Speed Steel Changeable-Pilot Counterbore, 21/32" Body Diameter with 4 Flutes

https://www.mcmaster.com/#3103A3" rel="nofollow - 3103A3  - Steel Pilot for Changeable-Pilot Counterbores, 3/16" Shank Diameter with 3/8" Pilot Head

https://www.mcmaster.com/#91255A647" rel="nofollow - 91255A647  - Button Head Hex Drive Screw, Black-Oxide Alloy Steel, 3/8"-24 Thread, 1-1/4" Long, packs of 25


Posted By: GeorgiaFlattie
Date Posted: 23 Jan. 2020 at 7:09pm
Originally posted by unclemoak unclemoak wrote:

Originally posted by jeeper50 jeeper50 wrote:

Great pics, what is the P/N for those bolts spot facer if you still have them.

Here are the numbers from McMaster 
 

https://www.mcmaster.com/#3102A25" rel="nofollow - 3102A25  - High-Speed Steel Changeable-Pilot Counterbore, 21/32" Body Diameter with 4 Flutes

https://www.mcmaster.com/#3103A3" rel="nofollow - 3103A3  - Steel Pilot for Changeable-Pilot Counterbores, 3/16" Shank Diameter with 3/8" Pilot Head

https://www.mcmaster.com/#91255A647" rel="nofollow - 91255A647  - Button Head Hex Drive Screw, Black-Oxide Alloy Steel, 3/8"-24 Thread, 1-1/4" Long, packs of 25

Thanks for sharing those part numbers. That's valuable tech.


Posted By: unclemoak
Date Posted: 25 Jan. 2020 at 1:13am
Originally posted by GeorgiaFlattie GeorgiaFlattie wrote:

Originally posted by unclemoak unclemoak wrote:

Originally posted by jeeper50 jeeper50 wrote:

Great pics, what is the P/N for those bolts spot facer if you still have them.

Here are the numbers from McMaster 
 

https://www.mcmaster.com/#3102A25" rel="nofollow - 3102A25  - High-Speed Steel Changeable-Pilot Counterbore, 21/32" Body Diameter with 4 Flutes

https://www.mcmaster.com/#3103A3" rel="nofollow - 3103A3  - Steel Pilot for Changeable-Pilot Counterbores, 3/16" Shank Diameter with 3/8" Pilot Head

https://www.mcmaster.com/#91255A647" rel="nofollow - 91255A647  - Button Head Hex Drive Screw, Black-Oxide Alloy Steel, 3/8"-24 Thread, 1-1/4" Long, packs of 25

Thanks for sharing those part numbers. That's valuable tech.


My mistake, you actually need the 5/16 pilot. The 3/8 is too big (I wasn't thinking about the major vs minor diameter of the threads)


https://www.mcmaster.com/#3103A29" rel="nofollow - 3103A29 Steel Pilot for Changeable-Pilot Counterbores, 3/16" Shank Diameter with 5/16" Pilot Head


Posted By: unclemoak
Date Posted: 02 Feb. 2020 at 10:49pm
Here's a video I did on how to do this upgrade.




Posted By: Fltfndr
Date Posted: 12 Feb. 2020 at 5:36pm
Anybody know if these same mods to the knuckle are necessary with a spicer axle?
 
Fltfndr


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Fltfndr
1948 CJ2A Restomod "Six Pac"
The object of war is not to die for your country, but make the other bastard die for his. George S. Patton


Posted By: jeeper50
Date Posted: 12 Feb. 2020 at 6:00pm
This mod strengthens the mounting point of the spindle, preventing the attaching hardware from pulling the threads out of the knuckle which is what happened to grandpas jeep. 

-------------

Belleview ol skool winch soon.
'48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers

Texan at heart,Alabama by retirement



Posted By: Fltfndr
Date Posted: 12 Feb. 2020 at 6:13pm
I understand  using the button heads and the modification to the edges of the cap.  I was referring to grinding  the ball end of the axle housing itself.
 
Fltfndr


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Fltfndr
1948 CJ2A Restomod "Six Pac"
The object of war is not to die for your country, but make the other bastard die for his. George S. Patton


Posted By: Stev
Date Posted: 12 Feb. 2020 at 6:37pm
There are probably two benefits to grinding the bosses flat inside of the steering knuckle:
1.  The button head bolts are a little more out of the way from the spinning axle join.  
2.   Full contact with the flat surface of the button helps with the frustum strength of the bolt compressing the assembly.

Look at slides 8 and 9
http://faculty.mercer.edu/jenkins_he/documents/MAE322Bolts2.pdf" rel="nofollow - http://faculty.mercer.edu/jenkins_he/documents/MAE322Bolts2.pdf


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Stev
1946 CJ2A Trail Jeep (The Saint), 1948 CJ2A Lefty Restored


Posted By: wheelie
Date Posted: 13 Feb. 2020 at 12:23am
  I did the job on a Dana 27......Spicer axles. I ground the housing because I was not comfortable grinding too much off the button head cap screw. 

I mounted the knuckles (with the seal in place) on the axle and marked the location of the knuckle seals at full lock in each direction to assure that I would not grind to much of the ball away and create a breach of the sealing surface. 

I don't recall if I could grind the ball with the seal removed from the knuckle or if I took the knuckle off and on and off and on etc., etc as I checked for clearance. 


Posted By: unclemoak
Date Posted: 13 Feb. 2020 at 2:49pm
Originally posted by Fltfndr Fltfndr wrote:

Anybody know if these same mods to the knuckle are necessary with a spicer axle?
 
Fltfndr

The style of axle shaft doesn’t make a difference. This upgrade strengthens the joint between the knuckle and the spindle. 


Posted By: Fltfndr
Date Posted: 13 Feb. 2020 at 6:21pm
Do you have any specific measurements of how much material to remove from the ball end of the axle housing?  Also any description of where to remove. I have the button heads done and installed and too chicken to just start blindly grinding on the housing.
 
 
Fltfndr


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Fltfndr
1948 CJ2A Restomod "Six Pac"
The object of war is not to die for your country, but make the other bastard die for his. George S. Patton


Posted By: Stev
Date Posted: 13 Feb. 2020 at 7:52pm

I would expect that you would want to retain as much material as possible and still get a 90 degree flat surface for the back of the button head bolt to seat against the casting.  Somewhere up in this thread I posted a link showing how the compression forces work with a bolt.  The bolt head needs to be in solid contact for the Frustum to be most effective when the nut is tightened.  Shear should not be an issue since the spindle has a step that goes inside of the steering knuckle casting.

The factory set up is a "Tapped Joint"  the button head bolt is a "Bolt With Nut"

Grip Pressure Cone
https://mechanicalc.com/reference/bolted-joint-analysis" rel="nofollow - https://mechanicalc.com/reference/bolted-joint-analysis


-------------
Stev
1946 CJ2A Trail Jeep (The Saint), 1948 CJ2A Lefty Restored


Posted By: Fltfndr
Date Posted: 13 Feb. 2020 at 9:41pm
Way above my pay grade. I am not dealing with the bolts, only the ball  end of the axle housing

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Fltfndr
1948 CJ2A Restomod "Six Pac"
The object of war is not to die for your country, but make the other bastard die for his. George S. Patton


Posted By: jeeper50
Date Posted: 13 Feb. 2020 at 10:17pm
The best way to figure out where and how much to remove, involves installing knuckle after installing button head bolts into knuckle and installing knuckle without spindle to be able to see where the bolts contacts axle housing. Looking inside as the knuckle is rotated side to side to indicate if you need to remove a bit more to clear the head. In the axle pic you can see the small area on front and rear of the outer edge that he ground on for clearance. 

Without using a formula to show it


-------------

Belleview ol skool winch soon.
'48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers

Texan at heart,Alabama by retirement



Posted By: oldtime
Date Posted: 14 Feb. 2020 at 12:28am
Just remove the minimum amount of casting to get a flat face for the bolt head to seat upon.
Then assemble knuckle to hemisphere to make sure knuckles will swing a full 29* without interference.

29* is required for Rzeppa shafts at maximum steer angle.
27-1/2* for Spicer shafts at maximum steer angle.
23* for Bendix shafts at maximum steer angle.



-------------
Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963)
Zero aftermarket parts



Posted By: Fltfndr
Date Posted: 14 Feb. 2020 at 1:18am
Can you remove some material from  the top of the buttonhead screw in addition to the edge of the screw?

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Fltfndr
1948 CJ2A Restomod "Six Pac"
The object of war is not to die for your country, but make the other bastard die for his. George S. Patton


Posted By: Nothing Special
Date Posted: 14 Feb. 2020 at 1:44pm
Is everyone talking about the same thing here?  To me it doesn't seem so.

These two posters sound like they are addressing the rotating part of the axle contacting the heads of the bolts"

Originally posted by Fltfndr Fltfndr wrote:

Do you have any specific measurements of how much material to remove from the ball end of the axle housing?  Also any description of where to remove. I have the button heads done and installed and too chicken to just start blindly grinding on the housing.

Originally posted by jeeper50 jeeper50 wrote:

The best way to figure out where and how much to remove, involves installing knuckle after installing button head bolts into knuckle and installing knuckle without spindle to be able to see where the bolts contacts axle housing....

But these two seem to be talking about making room to install the bolts in the first place:

Originally posted by Stev Stev wrote:

I would expect that you would want to retain as much material as possible and still get a 90 degree flat surface for the back of the button head bolt to seat against the casting....

Originally posted by oldtime oldtime wrote:

Just remove the minimum amount of casting to get a flat face for the bolt head to seat upon....

If I'm misunderstanding someone I apologize.  But if others are misunderstanding each other maybe this will help.


(oldtime might be getting back to Fltfndr's issue when he goes on to say:)

Originally posted by oldtime oldtime wrote:

....  Then assemble knuckle to hemisphere to make sure knuckles will swing a full 29* without interference.

29* is required for Rzeppa shafts at maximum steer angle.
27-1/2* for Spicer shafts at maximum steer angle.
23* for Bendix shafts at maximum steer angle.


-------------
Bob

Flatfender wannabe
https://www.thecj2apage.com/forums/nothing-specials-71-bronco_topic42024_post411994.html?KW=#411994" rel="nofollow - '71 Ford Bronco


Posted By: oldtime
Date Posted: 14 Feb. 2020 at 3:59pm
Quote  Can you remove some material from  the top of the buttonhead screw in addition to the edge of the screw?
I believe that a small amount of grinding on the bolt heads is better than milling too deep into the casting.

On my conversion I milled the minimum amount of material to get a flat surface. 
I use a drill press with a 1/2" end mill. 
I just manually slid the casting about by hand on top the drill press table. Cast iron machine very easily !
I did not need to grind any off the the button heads and can easily turn the knuckles 30* either way after assembly was complete. 
Note: one of  mine is a "double knuckle" and so that's why the machining looks so different between them.


-------------
Currently building my final F-134 powered 3B .
T98-A Rock Crawler using exclusive factory parts and Approved Special Equipment from the Willys Motors era (1953-1963)
Zero aftermarket parts



Posted By: Stev
Date Posted: 14 Feb. 2020 at 5:02pm
Sorry if we got off track.  In the old days when doing this conversion (to decrease the chances of the tapped holes in the casting failing)  it was done with regular bolts and the process involved grind mainly the bolts at 3 and 9 o'clock - if I remember the process correctly.  Button head bolts don't have high edges and corners so grinding should be minimal.

-------------
Stev
1946 CJ2A Trail Jeep (The Saint), 1948 CJ2A Lefty Restored


Posted By: wheelie
Date Posted: 14 Feb. 2020 at 11:14pm
I ground a little off the button head cap screws and also a little off the ball ends of the axle housing.


Posted By: drm101
Date Posted: 15 Feb. 2020 at 3:17pm
Nice video Unclemoak! 

-------------
Dean
'47 CJ2A "Mud Hen"
The less the Power the More the Force


Posted By: masscj2a
Date Posted: 01 Mar. 2020 at 12:27am
Great video, thanks for doing that.

-------------
1946 CJ2a Dauntless aka Jalopy
1946 VEC stock
1981 CJ-8 5.3 LS
1966 CJ-6 SBC TUX
1968 CJ-6 225 V6
1974 CJ-6 4.2
1967 M-416
East Coast Modified CJ's


Posted By: TXtea
Date Posted: 17 Mar. 2020 at 1:01pm
So I was looking over this mod and I really like it.  Thanks for the video Unclemoak.  But I was wondering if anyone has done this with the Tracker disc conversion?  I've got a 1/2" thick disc mount that also bolts to the spindle, so I will need longer bolts, but wanted to make sure the excess bolt length will not interfere with the hub.  I have very little clearance right now, so I'm sure it will be closer after this mod.

-------------
Ryan
'48 CJ2A SN: 161039


Posted By: Metcalf
Date Posted: 18 Mar. 2020 at 8:39pm
Originally posted by TXtea TXtea wrote:

So I was looking over this mod and I really like it.  Thanks for the video Unclemoak.  But I was wondering if anyone has done this with the Tracker disc conversion?  I've got a 1/2" thick disc mount that also bolts to the spindle, so I will need longer bolts, but wanted to make sure the excess bolt length will not interfere with the hub.  I have very little clearance right now, so I'm sure it will be closer after this mod.


Making sure the fasteners have a minimum of 3-4 threads past the nut is best.

I have done a lot of the drum brake Dana 30 axles with the factory studs. One of the reasons my brackets are a 1/4" ( which is still PLENTY thick ) is to allow using the factory studs and nuts in that application. If the bracket is any thicker you don't have any threads past the stock stud. If the stud is too long you risk hitting the back of the bearing hubs and spindle seal area ( especially with a worn inner wheel bearing ).

The best answer is to mock everything up. Maintain as much stud length as you can. It is fairly easy to shorten them if needed with a grinder and a nut/file to clean up the threads.

When we did the button head mod back in the day, we used two different lengths to allow the pocket mod for full turning angle.




-------------
42 MB that had a one night stand with a much younger 69 CJ5 and a 50s GM truck.






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