I tried the search and it gave some good info...but still didn't answer my question....
....doing the SOA this weekend and everyone says you gotta do a shackle reversal when you do the SOA...WHY!!! Seriously, I need your help in figuring this out.
I'll flip myself off right now...:flipoff2:
Thanks

No one wants to help a fellow cruiserhead out? Come on guys!

I think that the reason that everyone says that you have to do this is that you already have your suspension off, so you might as well do a SR. Also, it really helps to make the ride smoother. I know several people that don't have a SR up front with a spring over and they do fine. Except there vehicles are driven mainly on trails and very little street.
Doing a SR is not very hard, and makes your cruiser handle better as well. Just my experience though. HTH

Thanks for the reply ouibus...so the only reason to do the SR is for a better ride...doesn't help on the trail? Isn't there a reason why Toyota put the shackles in the front?:confused: :confused:

won't get much help from me either but look at the new 01-02 jeeps there shackles are also up front may pose this in the jeep section:D

Having a SR also helps in approach angle. By not having shackles up front that stick down, you have one less thing to get caught up on the rocks. Another thing that it does is allows you to get by with a shorter slip yoke on your driveshaft. The reason behind this is the driveshaft will compress as you flex and compress, instead of pulling out.
The reason that they came with shackles in the front, from what I understand, is to help with cornering. As you head into a turn the, your front axle will move over to the outside of the turn, and your rear will move to the inside of the turn. Keep in mind, this movement is very slight, but it does help in the turning of the vehicle. At least that is how it was explained to me on several occasions. HTH

Take a look on www.ih8mud.com there is an explanation why toyota put the shackles up front.

Did a shackle reversal on my truck because i had it stripped down to the frame, so it was an easy mod.
And since I live in Belgium where there aren't much places to wheel my truck will be used 90% on the road, I did the SR because, it's supposed to be a big improvement to the handling of the truck.
It's supposed to give a smoother ride, because when you hit a bump, now the axle can do a more "natural" backward movement wich results in a smoother ride (with the shackle upfront, the axle has to move forward into the bump wich results in a more brutal ride).
Also the steering should be more direct, because when you make a turn with shackles upfront, first the shackles will move and then the car will follow (big issue when you have worn out bushings). But with the fixed end of the spring up front, the car will follow immediately wich will result in more direct steering.
One of the drawbacks with SR is that the nose will dive under hard bracking.
I haven't driven my truck yet because i am still building it, but i got all the info from Harold Pietschmann, Jason Mace and Brian Swearingen and those guys know what they are talking about

Christof M.
1980 Bj40

Another thing that it does is allows you to get by with a shorter slip yoke on your driveshaft. The reason behind this is the driveshaft will compress as you flex and compress, instead of pulling out.

ouibus, you might want to re-think this. A SR causes the front shaft to change length more than a stock, front shackle. In my opinion the handling improvements claimed with a SR are a myth. The biggest reason for doing a SR is to improve aproach angle by not having the shackles hanging down in the front.

BigDave, you should read Jim Chenoweth's article in the IH8MUD tech section. His explaination of how the suspension works really makes a lot of sense.

Technically I am a newbie too so you can flip me off if you like. I find that you learn a lot more reading and wrenching than you do padding your post count.

Dan

as for the nose diving.....even under heavy braking and the rear discs (which are supposed to contribute to the nose dive) i dont have any problems, but ive extended my wheelbase to 100"

thanks for all the info/observations...what do you all think of Jim Chenoweths article...seems to me I should not do a SR now that I read that article...any thoughts?

Dan Gleason,
I can see how it would maybe make the driveshaft change length more, but in compression, not extension. With having the shackle up front, when the springs compress, the axle will be shifted forward, there by pulling the driveshaft out. If you are running long front springs with a long shackle, and you don't have a long enough slip yoke, you could pull your driveshaft apart.
Also, when most people do a SR, they recess the shackle into the frame. This makes the shackle movement limited, there by making the axle movement, back and forth, less.

ouibus, yor're missing something here. When the shackles are in the front, the springs pivot in the rear. Just like the front driveshaft pivots at the transfer case. They are almost parallel and swing in the same arc. You could remove the front shackles and jack the front end up over your head and the shaft still wouldn't come apart. With a SR the springs pivot in the front and swing in a different arc. As the axle swings down and forward the shaft swings down and back. So............when you do a SR and a SOA it usually requires a longer slip drive shaft.

Dan

Also, when most people do a SR, they recess the shackle into the frame. This makes the shackle movement limited, there by making the axle movement, back and forth, less

So, your saying that they do this to limit movement of the axle? Sounds counterproductive to me. Part of the lure of SOA would be its cush ride and good flex. I doubt people are recessing the shackle into the frame enough to cause bind. That would be caused by poor planning. With the flatter springs of a SOA, the shackle would be best placed in a 45 deg agle to allow for the most forward motion as reasonably flat spring will pull the shackle forward more than pusing it back on a Shackle reversal/SOA. With a SOA and SR, the axle will pivot on the radius of the axle to front spring hanger distance. Compound that with the effective shortening of the spring under both compression and extension(for a flat SOA spring) causes the axle to move forward under compression and extension. That is the reason for the longer slip joint inthe driveshaft.

Dan, what you say makes sense. I was just thinking purely on the way that the shackle moves and not how the springs move in relation to the drivesahft. Understanding that they move in the same arc clears up a few things. Thanks for that clarification.
Cruiserbrett, I wasn't saying that they do this to limit the spring movement. By moving the sackle into the frame, it sometime limits how far back and forth the spring can move. It is almost like running shorter shackles. You can design and build it so it isn't affected that much, but you are still losing some distance in the shackle itself.
As for the axle movement, I was explaining it if the shackle was vertical at rest and the spring had slight arc to them. That is how most of the setup I have seen are. In the case of the angled shackle and flat springs, what you say makes a lot of sense.

Thanks for the teaching lesson you guys. It is always good to learn something new.

You will need a longer slip driveshaft with a shackle reversed front versus a standard front Cruiser/vehicle.

If I'm not mistaken the slip yoke length becomes more of an issue when backing down or off something and the front is under extension, thus causing the slip to be *pulled* apart.

A longer slip yoke is a MUST with a shackle reversal. Extension is only PART of the problem. You will also get more compression in the driveshaft with a shackle reversal. I've seen several SR trucks seperate the (stock) driveshaft during extension, but I've also seem them bottom out and grenade the transfercase. Not a pretty site when the bottom of your case hits the dirt in a flood of gear oil. That's the end of the trail for you.

Bottom line is if you do a SR, plan on having a longtravel driveshaft made to handle the increase in compression and extension.

All that being said, my truck has had a SR for the last 4 years and I love it. My truck is still sprung under, but the shackle reversal still helped a ton with the ride and it seems smoother as I cruise over rocks and they're able to absorb some of the impact with the rocks. A well designed shackle reversal will not limit articulation (should improve it to some degree) but will provide a better ride on the street and the trail IMO.