Ok, I have a '84 4runner and my rear (stock) shackles are pretty close to being veritcal and I know that's not a good thing. I've searched and didn't find the answer to my question. Will longer shackles help? I was looking to get some +2" shackles, but then wondered if that would even help or make it worse? Can anyone tell me? I'm not looking to move the spring hangers and can't by new springs right now, but I want to fix this potential problem. Thanks in advance, Steve

 

the shackel angle will pretty much stay the same regardless of length.

i believe your only option is like you said, longer springs, or move the hanger.

 

Damn, I was afraid that was going to be the answer. Thanks for the response though. Is it possible the previous owner installed a lift that wasn't made for this truck? I would think a proper lift kit shouldn't make the shackles go soo close vertical.

 

i suppose so, Ive seen people do worse.

what kind of lift springs are they?

 

Previous owner told me skyjacker, but there are no markings or stickers for me to confirm. I only offroad with it and the ride is not bad considering the shackle situation. The front shackles are not vertical and so only the rear is a little "springey" I guess is an accurate description.

 

And what's the best way to measure leaf springs' length. I measured my current rears installed and they were 45" from eye to eye. NOT with the tape measure arched like the spring, but straight across from bolt to bolt. Is this right? And does anyone know of a spring that will give about 5"s of lift on a 1st gen 4runner and is about 47"s to 50"s measuring the same way?

 

when the springs are fully unloaded the shackles should be near vertical. it's possible they may even slant slightly towards the front of the truck. but what is important is that when the spring compresses, it swings towards the rear and not towards the front. when compressed, the springs will 'de-arch', become 'flatter', and push rearward on the shackle. if the shackle is too far to the rear, the spring will not be able to compress as much as possible and will limit up-travel of the spring.

 

agreed, although with the truck just sitting on flat ground, with no load, except for the weight of the truck. the shackle should be angled back at about a 15 to 20 degree angle.

 

I will agree, but all in all, what I said is true. As long as when unloaded, then consequently compressed, the springs do not cause the shackles to pivot over-center and towards the front when the springs are compressed... as long as that does not happen, there is no real issue with the springs or shackles and all is well and perfectly acceptable.

 

And I thought I read it, but wasn't sure, but apparently the original owner installed a lift of some sort.
The same thing holds true though, as long as when the spring is suddenly unloaded then loaded it doesn't cause the shackle to flip, there is no problem at all, even if the shackle is perfectly vertical when loaded.

 

For measuring leaf springs, I believe you're supposed to measure the distance eye to eye with the weight of the truck on it.

 

No, along the arch of the spring as if the spring were flat. The distance you speak of would change depending on how much the leaf spring flexes and be totally and completely unreliable and useless.

Here is a brief synopsis, some pictures and a measuring form.
http://www.eatonsprings.com/measuring.htm

 

Thank you all for info. Abe, I feel a little better now knowing a vertical or close to it is ok when unloaded. I believe it does pivot backwards when flexed but I will double check the next time out.

You've all been really helpful. Wabbit, I'm going to be ordering those shackles and extended brake lines soon, so look for my order in the near future.