step by step 3/4

[nick.gooding]

hey evryone i recently posted a topic about drop shackles
and most people with the drop shackles dont recomened them
and alot of people suggested the 3/4

i was wondering if i could get some more information on this such as price, what you need, how to do it and some pics would be great

and was wondering if anyone had any pics of the flex

[lay80n]

There are plenty of pics and write ups on this. GRPABT1 has detailed his in his members thread. Start there. Also search and bible.

Layto....

[GRPABT1]

AFAIK nobody sells it as a kit, so unless you know a good fabricator then you'll be up for a fair whack of money for it to be done right as with anything custom. But the good thing is if you're handy with the tools and can get a welder and grinder you can make one yourself.

Like mentioned though it has been discussed a few times before and there is a thread on here with details of my setup, and you can find pics in my members thread which is in my signiture.

[Gwagensteve]

Nick, 3/4 requires some fabrication ability and sound decision making.

Ideally, It's best applied to a narrow track sierra, or with the rear of a WT sierra converted to NT spring width. That's because NT's have the spring under the chassis which makes the conversion very much neater and cleaner.

Here's a photo of an opened up 3/4 on a narrow track chassis.

To do it like this you will need:

a set of 50mm wide trailer U bolts and spring plates
2X main leaves from a 50mm wide spring pack cut down
Longer shocks and custom shock mounts
relocate the fuel filler from under the chassis
Lots of grinding to remove the stock bumpstops and shackle hangers

That's about it. The fuel filler and the shocks and shock mounts are the hassle.

GRPABT1 has some photos of how to do it on a WT with stock spring spacing. IMHO though, I'd move the springs in if it was me.

Sorry for complicating things though - but I'd forget about the rear and RUF the front before I bothered with the rear. All the extra flex in the rear is only going to push the front end higher off the ground with the 5" of travel the stock front end has.

Here's a photo of a way bootyfab sierra that had MASSES of front wheeltravel and 3/4 rear. If that car was just 3/4 rear and stock front, it would probably be on it's side if tried to drive that spot.



It's all about the balance.

I'd vote more more travel in the front every time for a predictable, capable car.

Here's a car with RUF and OMe springs, shackles and bumpstop spacing in the rear. It doesn't have great rear travel at all, but the soft and flexy front makes it VERY capable.

with 33's


and another car with a similar setup.



3/4 rear might be a good solution for balancing the travel of RUF though.

Ruf is a lot of work, but if you are contemplating 3/4, you're already prepared to car your car up so don't rule it out.

Just my 2C.

[zookprojectfnq]

I built mine by looking at photos of grbabt1s build thead, I don't deny that. (thanks mate) There is more to it then in the photos,but you work it out as you go along. Mine was done on a 92 wt sierra. I have also made another clamp (not pictured) to clamp it while on the black top. It sits between the two square bars and is similar to the fixed clamp but with wing nuts.
If you can weld and use an oxy to a satisfactorily standard give it a go its very cheap. I used my old springs for main leaf and ordered new ones from fulcrum. They were $140 a pair delivered for efs. Then there's probably $30 of flat bar a few bolts. The dear part is whether you use your old shock mounts or new weld on ones that run to the center at the top. Then there's shocks. With the weld on mounts My old (new) Gabriel hiace van rear shock were right length almost spot on at full flex
I did the 3/4 to try and match the awesome flex I gained after doing ruff.
I will do full flex shots early next week if you want.
Still doing bar work

That is all
Chris

Build thread
http://www.outerlimits4x4.com/ftopic169485.php

[MUD-PIGSIERRA]

Excuse the shitty lookin scratched up paint work... A narrow track Sierra (NT) is far easier to do as Gwagonsteve has said, it allows the top leaf to run and rest along the bottom of the chassis when not in use. I have a capture pin which I leave in for most road driving.

Mine uses the Sierra shackle of the back and another leaf with U bolts and plate around the chassis. The U bolts allowed me to sort of fine tune the amount of rear flex from the top spring by bringing the clamp in a little further over the spring or moving it back for more flex but at the risk of bending the top spring under heavy load. That said with crawler gears and a set of front and back lockers really no need for 3/4 rear on a leaf Sierra. I can flex my wheel base on the RTi ramp without even pulling the pins out of a standard set of leafs on SPOA Sierra.

[ofr57]

hay steve did the critter run on sierra rears all round

i thought it was running longer springs

[Gwagensteve]

When critta was first set up 3/4 rear, when Mock and I put it back to SPUA, it ran OME rears all around.

When the MQ diffs went in it went to MK Patrol fronts all round. The photo I posted was when it was MK sprung, but for the purposes of the how the 3/4 was setup, there is no difference.

Steve.