OK, So, Mount the Shackle in front of the axle or behind? and why?

Here's the project:
SOA front Dana 44 on a pickup frame, daily driver and offroad rig.
The truck will primarly be used for rockcrawling but must also be capable of general offroad perposes.

Standard steering setup plan on Highsteer later.
Springs are 45" long. Will be running 35"+ tires with 5.13 gears and RS9000 Shocks

-SMART ASS

I was watching my friend wheel with his FJ40 and newly done shackle reversal. My rig at the time was a CJ7 with similar setup to his - 35s, lockers, mine even had an automatic. We both climbed the same rock, same approach - the FJ went up and over so smooth. I followed and the CJs tires contacted the rock and the darn thing felt like it wanted to jolt backwards. This happened all day. later, I put on a shackle reversal on that rig and have continued to do it for all vehicles. Works for me.

I vote to do a reversal stricktly for the increase in approach angle.

there are many pro's for shackle at the rear........ mine are.

but here are some negatives i've found with mine.
i run an automatic/dana20 transfercase which leaves very little clearance for the front drive shaft....during extreme flex with lateral axle movement (when shackles lean) i sometimes hit my drive shaft on my exhaust or torque converter cover & i'm running a small diameter driveshaft.....i'm thinking about putting on a trackbar because of this.....
also with rear shackles and suspension droop: your pinion starts pointing down, and then add torque which also trys to push the pinion down more and the clawing effect from the front tires and you can have a problem with your front U-joint angle maxing out. ( i rotated my pinion way up to help with this, :eek: see pic and also a longer stub and might be need.......:)
http://bbs.off-road.com/wwwthreads_uploads/53-663791-pinionwayup.jpg

COOL, COOL, INFO :D

124 people viewd this post, but only 13 votes :confused:

The advantages of a s/r are simply a myth. Especially off-road.

Anyone that believes that the pinion turning away from the transfer case is a good thing, needs to take a second look.

Also, as far as approach angle is concerned, the WORST approach angles I have seen to date are from s/r's with those massive fixed brackets in the front.

Also, with the articulation going towards the body, you will be limited on tire size, unless you move the axle forward. But the you have to deal with the tie rod/pitman arm conflict. I am running 38's with no sheetmetal cut on the front. Gee, I wonder how many s/r guys can say that?

Jeep put the shackle up front for roughly 50 years. Do you think that was an accident?

If it ain't broke, don't fix it.:D

Exactly what Bob/CA said!!!!;)
I just finished my SAS on my Tacoma and i put the shackles up front for the same reasons!! I have more clearence and a better approach angle with my shackles up front than the other SAS guys have with their front spring hangers!!
Shackles up front, no doubt bout it!:skull:

I vote for shackle in the rear. I have done a few conversions on jeeps before and the difference in ride quality is huge. The natural motion of bumps coming from the front of the truck is better transferred to the rear of the spring. Think about it. Why would you want to make the axle move the opposite direction of incoming shock. As for approach angle you don't need a lot of bracketry up there. Just 2 simple pieces of thick ass metal that are correctly welded will work fine. good luck.

Shackle reversal is awesome..............on the street! And thats where it belongs. On the trail i've seen it cause way too many problems - tires moving back into the body at full compression and drivelines coming apart at full extension being the most common. It just makes everything move the wrong direction as the suspension cycles.

Originally posted by Bob/CA
The advantages of a s/r are simply a myth. Especially off-road.

Anyone that believes that the pinion turning away from the transfer case is a good thing, needs to take a second look.

Also, as far as approach angle is concerned, the WORST approach angles I have seen to date are from s/r's with those massive fixed brackets in the front.

Also, with the articulation going towards the body, you will be limited on tire size, unless you move the axle forward. But the you have to deal with the tie rod/pitman arm conflict. I am running 38's with no sheetmetal cut on the front. Gee, I wonder how many s/r guys can say that?

Jeep put the shackle up front for roughly 50 years. Do you think that was an accident?

If it ain't broke, don't fix it.:D

BOB??????

you left out alot of details there bud....
Yeah I have a Boeing 747 and I to can fit 38's without cutting metal??????

WTF does that have to do with anything?
also jeep has been putting shackles in front for 30 years?? well the also put amc 20's ax15's and dana 35's in their shit!!! oh wait but the 35 can really be beefed up huh....

LOL whateva!!
and to answer the Question

the ride baby - all the other pros/cons balance out in my opinion

flat springs = better ride with shakles in front
high arch = better with shacle in rear


laterz!

Originally posted by KacksterK5
I vote for shackle in the rear. I have done a few conversions on jeeps before and the difference in ride quality is huge. The natural motion of bumps coming from the front of the truck is better transferred to the rear of the spring. Think about it. Why would you want to make the axle move the opposite direction of incoming shock. As for approach angle you don't need a lot of bracketry up there. Just 2 simple pieces of thick ass metal that are correctly welded will work fine. good luck.

SOA or SUA + flat springs=front shackle

Axle moves up and back on compression
Down and back on extention
Slight arch no big deal

SUA or SOA+high arched lift springs=rear shackle

Axle moves up and rearward on compression
down and forward on extention

My vote is SOA+flat springs(or slight arch) and front shackle

:flipoff2:

Originally posted by KacksterK5
I vote for shackle in the rear. I have done a few conversions on jeeps before and the difference in ride quality is huge. The natural motion of bumps coming from the front of the truck is better transferred to the rear of the spring. Think about it. Why would you want to make the axle move the opposite direction of incoming shock. As for approach angle you don't need a lot of bracketry up there. Just 2 simple pieces of thick ass metal that are correctly welded will work fine. good luck.

Who cares about ride *quality*? Only thing I care about on my rig is how far up the trail I can go.

Ride quality is for mall rats and old men. Buy a cadillac if you want ride quality

Originally posted by Moab Austin


BOB??????

you left out alot of details there bud....
Yeah I have a Boeing 747 and I to can fit 38's without cutting metal??????

WTF does that have to do with anything?
also jeep has been putting shackles in front for 30 years?? well the also put amc 20's ax15's and dana 35's in their shit!!! oh wait but the 35 can really be beefed up huh....

LOL whateva!!
and to answer the Question

the ride baby - all the other pros/cons balance out in my opinion

flat springs = better ride with shakles in front
high arch = better with shacle in rear


laterz!

Finally a decent post on the subject

Originally posted by chevota01
I was watching my friend wheel with his FJ40 and newly done shackle reversal. My rig at the time was a CJ7 with similar setup to his - 35s, lockers, mine even had an automatic. We both climbed the same rock, same approach - the FJ went up and over so smooth. I followed and the CJs tires contacted the rock and the darn thing felt like it wanted to jolt backwards. This happened all day. later, I put on a shackle reversal on that rig and have continued to do it for all vehicles. Works for me.

If you are *jolting* when you hit an obstacle, you need to learn to drive. Only *jolting* should be if you are running races/baja. Otherwise, you are on the gas too much. Try a softer touch, you will get farther, without having to RS every rig you drive.

Where is that novel I wrote on this subject.

All a RS is good for is ride quality.

Shackle Forward (SF) is a better wheeling setup.

With RS, when a tire contacts a large obstacle, the rotation of the tire rolls the tire back and away from the obstacle, reducing traction.

With SF, the natural rotation of the tire pushes the tire forward and into the obstacle, increasing traction. The more downward force on a tire, the better traction you get. RS reduces downward pressure. SF increases.

Also, RS allows the tire to get out of the way of the obstacle, without the rig actually climbing. Your approach angle gets worse, as that tire moves back. I have seen many RS rigs drive their bumpers into obstacles because the tire *got out of the way*. When a SF gets to an obstacle, it forces the rig up and over.

One point of RS that I will allow is that the RS does keep the rig closer to the ground, so COG is less of an issue. However, for most rigs, if the obstacle is big enough to worry about, you are going to need the clearance to get up over it without getting hung up.

Keep the RS for the old men, and at the mall.

Just my humble opinion.

Good info and opinions~!

MORE MORE~!!!:D

Ok Ill give you my opinion. I think it doesn't matter cause you are just a mall poser anyway :flipoff2: Are you talking on your ranger? I would say put the shackle on the front of the frame. The way the ranger frame is this will give you a spring that will sit much more level in relation to the ground and not have something hanging really low behind the axle ether. It should also make standard highsteer arms if you go the route fit much easier and no have cleance issues with the spring. Just something to think about.

Matt

I've got the shackles up front, semi arched springs, SOA, on a 97 s-10. My problem is "death wobble". I put johny joints in the eyelettes and they work real well except for they just add to the death wobble. The axle itself isn't vibrating, its the truck on the spring perches. I should get a track bar, but I"m going to still do the RS.

I did my SAS with the shackles forward. Being I used rear toys, they moved the axle forward and with 35's I only have 4-5" of spring sticking forward so I'm not worried about approach. Plus I can run a normal spline length front drive line with no problems. As far as the rear shackle voters saying the front wheels get pushed back, when in 4wd they're pulling you forward, I just don't understand that reasoning. The ride is definately a little (note little) rougher, but I'm still glad I went forward, not back.

Screw it all go coilover.

I agree that in some situations aproch angle is beter with SR but in front it pushes the axle foward which is good for keeping tires out of the fender plus lends it self nicley to climbing ledges cause of its designe it naturaly wants to go foward.

Originally posted by Bob/CA
The advantages of a s/r are simply a myth. Especially off-road...

Also, as far as approach angle is concerned, the WORST approach angles I have seen to date are from s/r's with those massive fixed brackets in the front.

Also, with the articulation going towards the body, you will be limited on tire size, unless you move the axle forward. But the you have to deal with the tie rod/pitman arm conflict. I am running 38's with no sheetmetal cut on the front. Gee, I wonder how many s/r guys can say that?

Jeep put the shackle up front for roughly 50 years. Do you think that was an accident?

If it ain't broke, don't fix it.:D

OK :rolleyes:

Depends on how they are done, in "kit" form I agree

I'm running 38.5's with no sheetmetal cutting and a S/R, well not your traditional hack job...

So with that line of thinking we should all be using a D30 front axle then right???

Have you ever applied more than moderate brake pressure to a shackle reverse vehicle, hell, try an emergency lane change manuver!!! There goes your "good for the street" theory. Just jam the brakes and hold onto the steering wheel with both hands. Seriously though, brake dive is a big issue, plus all the others above mentioned. Two of us on the Toy board are discussing how to Un shackle reverse our trucks!!!! If approach angles are your game, just choose the correct spring, short forward length(and plenty soft, solves your rough ride issue, and FLEXES lika a mutha), and go BIGGER in the tire department (IMHO!):D

Originally posted by jslamerman
Have you ever applied more than moderate brake pressure to a shackle reverse vehicle, hell, try an emergency lane change manuver!!! There goes your "good for the street" theory. D

Another good point!!;)

the biggest advantage of shackles in the front in my opinion is the fact that the tire moves foward during compression which helps to jam the tread into the rock when you are forced to bump it slightly. It might make it feel rough but the tread is grabbing harder and it only leaves one place to go. up and over!