Adding Shackles

I have a 1971 cj5 with the BDS 2.5 suspension and stock original shackles. I have 31"X10.50"x15". I am going to put on some 33x10.50x15 tires with 8" rims. I want to maintain the same clearance I currently have. How tall of a shackle can I use to achieve my goal. I want 1" or 2" lift from the shackle. Does it change the steering, alignment, or anything in a negative way?

Thanks

Julius

 

Yes, it'll change your steering geometry (caster), and may make your steering more twitchy. I have run extended shackles on previous vehicles, but personally, I'd be hesitant to do so on such a short-wheelbase vehicle. 1" might not be bad. 2" sounds like a LOT.

Do you know you'll have a clearance issue going with the 33s? I'd test the articulation/clearance with the stock shackles first if it were my vehicle.

Craig

 

to get 2" of lift from just swapping out shackles.. those shackles would probably have to be over 4" longer than stock, that's getting pretty long.

 

Thanks for clarifying this...I read that the shackles would be either 1" or 2" longer than stock, not the same respective amounts of lift.

 

If you re switching from a 31” tire to a 33”, you’re only losing 1” of clearance between the tire and fender. To get that 1” of clearance back, you need shackles that are 2” longer than stock.

Can’t comment on how that will affect your geometry/alignment, as it’s dependent on your exact setup.

 

I'd just wait until the tires are on and flex it out. Even money everything will be fine.

 

Nothing wrong with running a 1" longer (1/2" gained lift) or 1-1/2" longer (3/4" gained lift). You will loose a little caster and need to make sure your drive line angle is still acceptable. Make sure you also check your toe in adjustment as well.
If you do go with longer shackles you will want the H type with the cross piece in the middle. The H pattern is much more stable on road and wont affect on road handling as much.
You must be considering running Rubicon with us eh????

 

FWIW Julius, I run a 2.5" lift and 1" longer shackles ( .5" lift ). I am pretty confident I could go back to a stock shackle and be fine. I run 9.50 wide tires but that will change.

I tend to agree that you should wait and see what happens before buying longer shackles.

My pizza cutters still rub the wheelhouse at the rear of the JEEP at full stuff. Be prepared for this if it doesn't already happen to you.

 

The 33" tires will hit the front springs sooner so you will have to adjust your stops. This will also give you less turning radius. You could add wheel spacers to get
some or all of that back. A shackle lift will affect your caster and shims will correct that. A 4-degree shim will drop your front about 1/2" so you lose what a 1'
shackle lift gives. If you have a 1-piece tie rod the shim help raise the tie rod and one hole TRE above the springs for more clearance. BDS springs have a
spring clamp right in line of the tie rod. The stock shackle is 2-3/4" on center, so a 1" lift shackle would be 4-3/4' and a 2" inch lift would be 6-3/4" long.
I have the 2-1/2" BDS lift and not liking the nose down look and using a 1/2" [1" over] shackle with 4 degree shim. Put 4" Superlift front spings on and ended up
with the same ride height as the BDS. Going to try the Skyjacker 4" lift and see how that goes. Would like to run a stock shackle. Note: 1" body lift on frame and 33" tires.
Stock shackle on the rear. Probably end up making a franken pack or custom springs from Alcan or Atlas. I may consider YJ springs at that point.
BDS needs more arch in their front springs but not going to happen.

 

Agree with others that you'll be fine with 33" tires and minimal shackles. Here's my '71 on 32x11.50-15 tires with 6 degree camber shims and stock shackles all around:




I've since added 1" longer than stock home-made H-shackles in the front to get it to sit more level, not for clearance issues. As others have noted, the BDS front springs could use a little more arch:


How it sits today. 33s would be no issue:

 

Yes I have noticed that my jeep sit's a little low in the front also. Thanks for all the good advice.