BC 4x4 Forums banner
1 - 8 of 8 Posts

·
Premium Member
Joined
·
1,541 Posts
Discussion Starter · #1 ·
I was reading the new four wheeler mag and under specs alot of trucks had shackle reverses. So what is a shackle reverse? Is it just putting the shackles from the front of the leafs to the rear?

------------------
92 yj 2 inch body lift,lift shackles, 2.5 rancho lift springs running on 33's
 

·
Registered
Joined
·
183 Posts
no its flipping the shackle so instead of the shackle going up ya flip it and the shackle goes down and gives you about 3 inches of lift.. ON A CHEVY


------------------
81 3/4 ton chevy w/ 7" susp lift & 3" body lift
NEW 35" mud-terrains, pro-comp off-road lights
OH DID I MENSION I HAVE AN alarm!?
<SPORTIN A CHEVY> <BeCaUsE Im SiLlY lIkE tHaT!!!>
 

·
Registered
Joined
·
394 Posts
A "shackle reversal" is when you have a vehicle like a YJ that has the front spring's shackle on the front end of the springs...and you reverse that so the shackle is on the back end of the spring. The solid mounting point that was on the back is now used up front.

Some people feel this is a good modification because the shackle is allowed to move more naturally creating a softer ride. Others feel the negatives outweigh the postives.

A "shackle flip" is what I have seen as a common term to describe what jasonped explained.

------------------
jo-jo
http://island4x4.com

"Give a monkey a brain and he'll swear he's the centre of the universe". - Fishbone circa 1993

"I love the smell of Argon in the morning, smells like victory".

"The right to be heard does not automatically include the right to be taken seriously."
- Hubert Humphrey
 

·
Registered
Joined
·
802 Posts
It's also if you have a vehicle like a solid-axle Toyota, and you move the shackle from the rear of the front spring to the front of the front spring, so it's like a Jeep. Apparently the rationale for this is improved pinion angle (because the rear of our front springs sit lower than the front of the front springs) no need for a long-travel front driveshaft (axle moves towards the xfer case on droop), and no rubbing on compression (the tire moves away from the rear of the fenderwell instead of contacting it).

Despite those obviously good points, I'm not convinced that the opposing force on the springs is a good thing. MEK is trying to convince me otherwise.



------------------
Greg Sue
85 Toyota X-cab
http://media-north.com/4wd/
 

·
Registered
Joined
·
50 Posts
Some opinions on shackle

With the shackle on the front, when the spring is compressed it forces the wheel forward. Some people feel this forces the wheel into the rocks and makes it harder for climbing big rocks. If you have a rear locker this is probably true. for a truck with open diffs it provides a benefit by forcing the wheel forward to gain grip. fine for medium sized rocks and with out lockers you won't be climbing up a 90% tire high rock.

Rear shackles also require a longer pinion movement. I've heard they also help with road handling. However if you have nice soft springs for articulation it can really weird out the highway driving. With the shackle up front the weight of the vehicle shifts to the front outside tire compressing the spring. As the spring lengthens it helps to turn the vehicle because the radius distance between the rear and front tire lengthens. With soft springs and the shackle to the rear you get the oppposit effect. So on the harder you corner the shorter the radious created the more the vehicle wants to jump the other way. The guys that reverse the shackle and also harden up the ride don't notice these effects.
These last comments only apply to spring under applications. Once you do a SOA the physics reverse.

This is my understanding of it to now. Be glad to learn more though from the leonardo's out there.


------------------
4x4pics

[This message has been edited by Sid the Squid (edited March 18, 2002).]
 

·
Superfly
Joined
·
8,221 Posts
Originally posted by Sid the Squid:
These last comments only apply to spring under applications. Once you do a SOA the physics reverse.
Not exactly. The key factor is whether the spring is arched or not. If it is, then compression will lengthen the spring by flattening it. With an SOA, the springs are _usually_ flat, so compression will actually negatively arch the spring, shortening it. BTW, when I say lengthen or shorten, I mean in relation to an absolutely straight horizontal line. However, with SOA setups with arched springs, the springs will flatten upon compression, just as you would expect with arched SUA springs.

...lars



------------------
19911995409993004:144444.103512.58274



Join | BC4X4 | .com
 
1 - 8 of 8 Posts
Top