I've read a ton of posts and threads but...620 lowering.

[ohmrchristopher]

I also just read through this forum and it was good!! Lots of info and especially part numbers for the shox!! But there is one thing I am missing. What are theses shims, where do I buy those (p/n welcome) and where do I install them? Also I love the body pictures but how about some underside pictures? How far is your exhaust from the ground? Whats your bumpstop distance? How does your drive shaft angle look??

 

If I could get some snaps of these items it would help take out a lot of confusion.

 

Oh and I need to change out my leaf bushings, radius arm bushings, and basically any rubber mount under the truck. 2 questions here, 1) anyone know p/n's for these bushings (any or all)? I was thinking of cutting up some hockey pucks for the leaf bushings because of question 2) should I try to find these 4x4 leafs or keep the stock 620 ones? I have nill stock for datsuns in the JY and so finding something like leafs may next be impossible. Can someone clear up why I would want 4x4 leafs? Are they softer becuase they're more leafs in the pack? Are they a bigger stack up and thus you do not need as big a lowering block?

 

Thanks in advance if you have the info!!

[datzenmike]

The 4x4 springs are flatter and stiffer. When a vehicle is lowered it's always better to run a stiffer spring to resist suspension travel on a dip in the road. I see some dip shits take leaves out to lower. Yeah that lowers it but now the truck springs are so soft that the suspension travel is increased. Decreased clearance + increased travel =

 

Chester on here put 720 4x4 springs in his 620.

[ohmrchristopher]

That is a picture of a pulled torsion bar and a cross member? I understand how spring rates work, I just dont know what the 4x4 spring looks like. Is it a multi-leaf pack? I have a single leaf and just a small, what I would assume helper spring.

 

As we can see here.

 

Datsun 620 029 by NickedKnuckles, on Flickr

And here off to the left.

 

Datsun 620 019 by NickedKnuckles, on Flickr

[]2eDeYe]

Just an FYI, that effectively lowers your spring rate and rating to almost 0. ;)

[ohmrchristopher]

2eDeYe' timestamp='1333063204' post='662793']

Just an FYI, that effectively lowers your spring rate and rating to almost 0. ;)

 

What does?! Explain sir!

[]2eDeYe]

2eDeYe' timestamp='1333063204' post='662793']

Just an FYI, that effectively lowers your spring rate and rating to almost 0. ;)

What does?! Explain sir!

 

 

Each leaf in your spring pack adds an amount of spring force and also raises your spring rate.

 

As an example (I do not know the factory spring force or rate for the leaves)

 

If your main leaf has a spring force of 100 lbs and each added leaf adds an increasing amount of force, say 75 lbs for the next leaf, 50 for the next and so on up to say a total of 350 lbs. You are removing that spring support for each leaf you have removed. Also as the spring compresses throughout the suspension travel the rate increases due to the arch of the leafs and each smaller leaf compressing at a different rate due to it's shorter length until you compress the overload leaf which dramatically increases your spring force due to it's thickness (increased spring force). The more leafs you have in the pack the better your spring rate, which is the increase in stiffness of the suspension as the springs compress.

 

When you only have the main leaf left your rate is non-existant and your spring force is only what that main leaf can support, which isn't much compared to a complete spring pack. Now you end up overworking your shocks as the spring is no longer supporting the full weight of the truck as designed and you end up with a real floaty rear end that ends up boucing a lot once the shocks can no longer keep up.

 

Hopefully I explained that right, it is still a little early :)

Edited March 30, 2012 by ]2eDeYe
added quotes from the previous page

[Zeusimo]

4X4 Side By Side With Stock 620 Springs

[metalmonkey47]

Siempreloco where are you??

[Zeusimo]

Sleeping... It's Almost 1 AM

[metalmonkey47]

Sleeping... It's Almost 4 AM

 

fixed for east coast

[]2eDeYe]

The 4x4 springs look a little longer in that picture. Are they? Wonder what the shackles on the 4x4 look like.

[Zeusimo]

Yeah They Might Be 2" Longer... Maybe Cuz They Are Shorter??

This Is After I Shaved The Springs Cuz They Kept Rubbing...

I THINK They Are The Same Shackels... Don't Remember

Anyways... They Bolt On Fine

[datzenmike]

All 520/521/620/720 leaf springs are the same length... 1,200mm or 47.27" long.

 

1/ You have a 620 with stock rear springs and ground clearance is say 4" before you hit something. You drive through a dip in the road and the body slams down 3" and everything is ok. Now without changing the springs you block the axle 2" higher lowering the body 2" and reducing your ground clearance to 2" and drive through the same dip and the body tries to travel 3" in a 2" space and hits the ground. Bad enough with all your springs

 

2/ You have a 620 with stock rear springs and ground clearance is say 4" before you hit something. You remove all but one leaf from the springs and the truck drops 2". The spring rate is radically altered (reduced) and now the springs will deflect 6" when hitting a dip in the road. You have 2" of ground clearance and 6 inches of possible travel. Worse case.

[ohmrchristopher]

If that's stock 620 leaf pack then by comparison it looks like my truck is missing a leaf? I only have the main leaf and that stubby little one. I guess someone took out a leaf at one time? Is that what everyone noticed?

[ohmrchristopher]

so upon further inspection a leaf has been removed from my packs. I can see where the end tabs were bent over at the end of the shorter leaf. This is a bummer...

[]2eDeYe]

Just find yourself a set of 720 4X4 leafs and go from there :)

[ohmrchristopher]

KYB Gas-A-Just Rear Shocks - KG4605A - Same product in CarQuest box 1844257

 

KYB Gas-A-Just Pinto Front Shocks - KG4511

 

Ok, datfuk, I'm stumped. I ordered these exact shocks and the metal insert in the eyelet end A) is too small to mount on the truck, and B) wont come out. The Pinto one is even longer of a insert!

 

So how did you get the inserts out of the shocks? And did you replace them with a different one or are you just running shock rubber on the mount bolt?

And why are the dust cups/caps upside-down? That's gonna trap any water in there and cause rust.

 

Unless I am using the rears in the front and the fronts in the rear??

[Siempreloco]

Ok, datfuk, I'm stumped. I ordered these exact shocks and the metal insert in the eyelet end A) is too small to mount on the truck, and B) wont come out. The Pinto one is even longer of a insert!

 

So how did you get the inserts out of the shocks? And did you replace them with a different one or are you just running shock rubber on the mount bolt?

And why are the dust cups/caps upside-down? That's gonna trap any water in there and cause rust.

 

Unless I am using the rears in the front and the fronts in the rear??

did you use his numbers or mine? because i fixed one he posted wrong, the rears are KG5447

The pinto fronts are KG4511, and require some kind of modifying, if you look around enough im sure there's a thread about it.

[ohmrchristopher]

did you use his numbers or mine? because i fixed one he posted wrong, the rears are KG5447

The pinto fronts are KG4511, and require some kind of modifying, if you look around enough im sure there's a thread about it.

 

Nooo, fuck! Really? I bought the wrong ones... Ugh. So I have the Pinto ones, will look up modifying them, but I bought the wrong ones for the rears...

Wait, why do we use the Pintos again? Cause well I cant really return the 620 front ones, I could return the Pintos and buy 620 rear ones for now...

[DatDoug]

15x8 Blazer Ralleys with 205-55's

 

3" blocks with KYB gas shocks & 1 leaf removed in back (74 truck so you can get away with removing a leaf cuz they have like 10 of them!) Makes for a smoother ride

 

Front torsion lowered with the bumpstops cut down to an inch with pinto shocks

 

[ohmrchristopher]

Uh gee thanks. Still wondering if I should return the Pinto shocks (new, in box, untouched) in exhange for 620 REAR shocks, because the 620 FRONT ones I bought (by accident) are not in the best condition to go back...

[Siempreloco]

No, id still figure out how to run those pintos, maybe someone else on the forum would like the 620 fronts, if they aren't effed up i may even be interested.

[ohmrchristopher]

All i did was drill "drain holes" in the top off the dust cap because I was trying to mount them upside down. And try to push out the metal bushing. I can fill the holes in with my welder and the bushing is still in all a bit scuffed. I would trade them for a stock wheel D:

 

Thanks for the help, I'll run the Pintos and put an add up for the 620 fronts.

[79620kc]

 

the frame is notched in the back. 4" blocks. the front spindles are modified belltech drop spindles for a frontier. removed the bumpstops in the front. the front hubs and brakes are hardbody.

might not look that low but the frame rails are no more than 2 1/2 or 3" off the ground and the exhaust is about an 1 1/2" off the ground which explains why ive replaced that 2 foot sections from headers to cat 3 times :w00t: its wayyy low but its do able and im used to it :ninja:

[chester]

I will get pics of mine tomorrow. As of right now I am running 720 4x4 leafs and 3" blocks and my rear end is about an inch from the frame. Then in front I raised my shock mounts and running kyb # 344469 shocks which are for a 2000-04 frontier they have a compressed length of 7.79" and a kyb for a 620 is 8.4"ish compressed. The frontier shocks are stiff but I prefer stiff suspension. also I have stock bump stops that have been cut down to half inch. Here soon I will be cutting all of that crap out I think.