Forum Home Forum Home > CJ-2A Discussion Area > Tech Questions and Answers
  New Posts New Posts RSS Feed - Talking about Caster and shackles
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Talking about Caster and shackles
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
Mark W. View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 09 Nov. 2014
Location: Silverton, OR
Status: Offline
Points: 7982 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark W. Quote  Post ReplyReply Direct Link To This Post Topic: Talking about Caster and shackles
    Posted: 21 Jan. 2020 at 6:51am
So reading all the time about Jeep stuff I came across someones concerns about Castor Shims and how they should be installed. This got me reading some more stuff about alignment in a Willys.

Stock C Shackles are roughly 3" center to center I am told (mine are LONG gone) the Fancy Shackles I made measure 3.7" center to center.

Will this effect my Castor enough to worry about? I do plan on having CHUG run through a friends alignment shop once its all on the road and such. But I was wondering should I scare up some Shims to have on hand should he need them to get me to spec?

Tires will be 29" tall on Wheels with matching offset and Backspacing as stock wheels. But 6" wide.
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
Back to Top
jeepsterjim View Drop Down
Member
Member


Joined: 13 July 2011
Location: lincoln, ca
Status: Offline
Points: 1283 		Post Options Post Options   Thanks (0) Thanks(0)   Quote jeepsterjim Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 7:14am
When doing custom work on commandos springs, shackles, etc., a highly rated off-road alignment shop drilled into my head that you can only go 1" longer in shackle length before messing up castor and such. After that shims or tilt diff with new axle/spring perches to the correct castor and weld up.
Jim
CJ-2A - 81299
Back to Top
nofender View Drop Down
Member
Member
Avatar
Sponsor Member x 3

Joined: 10 May 2016
Location: Maryland
Status: Offline
Points: 2035 		Post Options Post Options   Thanks (0) Thanks(0)   Quote nofender Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 10:13am
I agreed with the above. 

With your .7 increase in length, there will be an ever so slight change in caster. But not enough to worry about or adjust out, in  my opinion. 
46 CJ2a rockcrawler
46 CJ2a - 26819
46 Bantam T3c "4366"
47 Bantam T3C - 11800
68-ish CJ5
Back to Top
jeeper50 View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 01 Mar. 2008
Location: Spanish Fort AL
Status: Offline
Points: 2579 		Post Options Post Options   Thanks (0) Thanks(0)   Quote jeeper50 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 1:27pm
When you get it driving, you'll be the first to know that the caster is jacked up by the way the jeep hunts down the road. 

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

Texan at heart,Alabama by retirement
Back to Top
Spinnas View Drop Down
Member
Member


Joined: 24 Apr. 2018
Location: AZ
Status: Offline
Points: 375 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Spinnas Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 2:31pm
Stock is 2-3/4” shackles. Yours are essentially 1” longer than stock. Myself in my 2A and my dad’s 3A both have 3-3/4” long front shackles for a 1/2” lift. Total caster change is 1.5 degrees less than stock. My dad’s has very nice and tight steering, while my steering is a sloppy loose POS. Both have 7.50-16s and drive 50mph regularly with no issues. Just our actual first hand experience.
Back to Top
rocnroll View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 20 July 2005
Location: Tuscumbia, AL
Status: Offline
Points: 13584 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rocnroll Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 2:51pm
The ever so slight increase in caster should actually make it go down the road straighter....not hunt.
 
Think 70's chopper, that wasn't just a styling thing.
 
Back in my buggy days you actually built in more caster to make them track straighter, add stability and as a side affect the wheels would have more of a lean to them when turning hence better 'digging in' of the front tires when turning.....picture the way a road graders' front wheels 'flop' when they turn. A chopper front end does the same thing....it doesn't really 'turn' as much as it 'flops' from side to side.
 
Granted these are extreme as compared to what we are talking about but it lets you envision it a little better.
 
In this case I don't think there will be enough change to even notice.
 
 


Edited by rocnroll - 21 Jan. 2020 at 4:46pm
'47 CJ2A PU
'48 CJ2A Lefty

"Common sense is not that common"
Back to Top
Spinnas View Drop Down
Member
Member


Joined: 24 Apr. 2018
Location: AZ
Status: Offline
Points: 375 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Spinnas Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 3:33pm
Originally posted by rocnroll rocnroll wrote:

The ever so slight increase in caster should actually make it go down the road straighter....not hunt.
 
In this case I don't think there will be enough change to even notice.


This would be a decrease in caster.
Back to Top
rocnroll View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 20 July 2005
Location: Tuscumbia, AL
Status: Offline
Points: 13584 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rocnroll Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 4:43pm
You are correct....my apologies.
 
Now my disclaimerLOL...I wasn't into my second cup of coffee yet and was thinking backwards (well, just not thinking of the 'stock' setup)
 
When I built 'Frankie' I did a shackle reversal when I hung my springs....thus, my front axle is hung with the shackle in the rear...the increase in length of the shackle (in that scenario) forces the pinion down therefore more positive.
 
In the stock setup you will indeed be forcing the pinion up.....negative.
 
My explaination is correct in theory (and correct in MY situation just not in a stock situation where the shackle is in front of the axle) just wrong in this situation therefore I will remove it.
 
Sorry to have clouded the issue but I think the answer is still....this slight change wont affect anything much.
 
 
 
'47 CJ2A PU
'48 CJ2A Lefty

"Common sense is not that common"
Back to Top
Mark W. View Drop Down
Member
Member
Avatar
Sponsor Member

Joined: 09 Nov. 2014
Location: Silverton, OR
Status: Offline
Points: 7982 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark W. Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jan. 2020 at 4:52pm
Well I checked and I can get .5, 1.0, and 1.5 shims easy enough so if my alignment guy or flying down the road with wild abandon indicate it shouldn't take but a half hour to add a little more. I'll just keep it in mind. Thanks guys.
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
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2022 Web Wiz Ltd.