jumper_bob

Hi guys, so for once I managed to get an awesome score off craigslist:

$40 for all of the following, from a 98 Runner:



1 - rear coils that dont sag (as a matter of fact, I saw a picture of that truck with these coils on it, and it has a GOOD rake to it, so the springs, I assumed, were plenty firm, and installation bore out that result - see below questions!)
2 - front coilovers, stock, but again in great shape
3 - front 4-piston calipers with good pads
4 - front rotors, still very thick and not scored

So I got all the stuff from the guy, and proceeded to start the install.

Prior to install, the truck was sitting like this:







Visually it wasnt too bad, but as you can see underneath, the springs are actually pretty flat; and with the top on, EXTREMELY flat, super stiff harsh ride.

So I got the right side done; the springs were so stiff and the coil compressor I rented from AZone was the "inside the coil" kind, so wouldnt work to compress, it would hit the bumpstops.

I had to drop the whole leaf (was doing bushings anyways, so no big deal), still had to compress the coil by hand about 1 coil, but it worked okay, then jack up the axle and pull tension a couple of places with a ratchet strap to line the leaf spring bolts back up. These coils are STIFF!@!!

I also had some longer shackles sitting around, and decided to put those in; as with the stiff coils I was worried about "forced droop" when wheeling, and possibly reversing the short Toy shackle, with ensuing carnage undesired. So I think that with these coils, longer shackles probably necessary. Mine are about 2" longer than stock.

Anyways, I ended up with more lift than I was hoping for:



and gained about 5" of lift:



Its a little funky right now, just one side done, but I am not happy with TOO MUCH lift!!!! I have measured while the truck is in a few different spots, and actually I think I have a bit more height than the above picture shows, about 1" more or so.

LOL, how often do you hear that?!?!?

But I just wanted a slightly better ride, some load capacity, and cannot afford or have time to lift the front to match right now...

Of course, the longer shackles play a part; I have a steel flat bar I am going to make shackles out of; I think that 1" longer than stock will ease my concern of shackle inversion, with only gaining 1/2" extra lift.

My current thought is that I want to reduce the amount of lift I have gained, so the truck is more level and doesnt look so high in the badonka-donk end.

I am going to do the left side today, in a couple hours; and am thinking that I may take out the overload and lowest leaf, and just leave the top two leaves. That, in combination with just-longer-than-stock shackles, should LOWER the lift I got back to a reasonable level, methinks.

It seems that I gained, with these particular coils, at least, and maybe a bit more, than other people who have installed the 2nd gen runner coils. (Accounting for the longer shackles.)

Since its obvious that these coils are now performing the weight-carrying duties, it would seem that the leafs are now only serving to locate the axle; in which case I should be fine to remove the overload and bottom leaves. And combined with different shackles, should put me at about the height I want. Another benefit of this would be to reduce what is currently a pretty stiff spring rate, between the leafs and the coils; resulting in a decent ride, and some articulation, without sacrificing load carrying. I mean, these coils are pretty close to factory-new-strong! I havent driven it yet, as only one side is done, but am concerned about a very stiff ride.

Another option I am considering is to cut off a coil or two, which might fix all the above problems.

Anyone have any thoughts?

- Scott

JohnnyCanuck

Drive it for a bit after you're finished and see how it sits. You can also cut the coils to make them shorter.

derockus

iTrader: (1)

Yeah, you can cut the coils but you should know that cutting them will make them stiffer (higher spring rate).

jumper_bob

Dang; if cutting the coils will make them even STIFFER, than that is not gonna work. Looks like its "take out some leaves" time. I think I'll try that on the left side, see how it sits compared to the right; then decide which is better.

derockus

iTrader: (1)

Yup, sorry man.

"k" is the "spring rate", or the inches of deflection per pound of force applied to a compression spring.

k = [G*(d^4)]/[8*n*(D^3)]

G = modulus of rigidity of spring material (steel). this will not change if cut
d = wire diameter. not changing if cut
n = number of "active" coil (ie, those that can move, like if you have flattened ends). this WILL change.
D = mean coil diameter. this will not change if cut.

As "n" gets smaller "k" gets larger and your springs get stiffer.

jumper_bob

Derockus, thanks! that is great info. I dont have extensive experience setting up suspensions lol so its kind of "trial and error" to see what works. I am just about to go out and do the left side, so its actually pretty convenient to remove the bottom leafs; I gotta replace the bushings anyways, and to even get the coil in there safely, have to drop the whole axle; so no biggie to take out some leafs. (a good excuse to slap some paint on a few places!)

Thanks again for the help, I'll post pics and update later after a test drive, see how it works!!!

- Scott

Inu

So you put 3rd gen coils. Isnt the common spring 140lb or tj coils? My bet is even without the leaves your lighter 1st gens gonna ride like a dump truck.

derockus

iTrader: (1)

from reading a lot of the Zuk mod threads on here people tend to go with the 125#/in or 150#/in black magic springs. i used TJ front springs cut to 12"... I tried to find the stock spring rate for those and it's i guess 140-160#/in depending what you read. so i made mine a little stiffer. mine rides real nice when loaded up heavy for camping. riding around totally empty, top off, and only me driving its a pretty stiff rear. personally, i'd rather deal with stiffness while empty and be cushy when i'm wheelin' around fully loaded.

jumper_bob

Ooops, there is a typo up top - the truck I got these from is a 1996, not a 98. sorry for that confusion.

I didnt look closely at the guys truck when I picked up the parts, but here is a pic of his truck from CL:



Looks like a 96, right? I will text him today and double check.

anyways, got the left side all done, took a while to cut out the old bolts and bushings....man, that chore is FUN! haha. Only broke one u-bolt, 1/2 a shackle, 2 sawzall blades, and one drill bit.

Pulled the two lowest leafs out, had to get an M8 allen head, grade 10, to re-pin the two skinny leafs together, and to get the centering pin to fit in the holes on the spring pads and the bumpstop. Also had to put some washers/spacers under the u-bolt plate, as with the removal of two leafs, that effectively pushed the u-bolt plate up the threads of the u-bolt, so high that I couldnt tighten the nuts. Not super happy about that method, but planning on a u-bolt flip kit soon anyways, so its fine for now.


And the bolts I got for the new shackles were too short - I didnt factor in that I was using thicker metal for the new shackle sides when I was at the store. So the truck stayed on the jackstands overnight till I can get to the store in a bit for some longer bolts.

Should be done this morning; once I get the long bolts I need, I will bolt up the left side, leave the right side, drive it around the block and see how the two different sides compare.

jumper_bob

Well that didnt work. LOL.

coils are just way too stiff. Removing leafs just created axlewrap; noticeable while shifting gears on the road, and very bad while in 4low going up a rocky wash.

And the coils are so stiff, that the axle doesnt articulate barely at all, instead simply lifting the body:



In the photo it *looks* like its compressing a little bit, and it is, but it never compressed any more than that - look at the hitch for reference; its almost the same angle as the axle.

Oh well, it was worth a try. Time to pull them out and put the leafs back together. At least now that I have new bushings and bolts, the leafs and rear axle come apart easily and quickly!