What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

rear leaf spring lenth/POSITION *post #6

original balzer

original balzer

1/2 ton status
Joined
Nov 17, 2004
Posts
4,660
Reaction score
2
Location
roosevelt utah
First is 2" worth the effort for the rear springs(54" over 52")? Of course it would be the same amount of effort as I am already doing BUT I already have 52"'s should I find some 54"'s? OR Find some even longer yet?

Second long side verses short side. Can I put the short side to the rear to kick my axle further back without any real drawbacks? I may use some zero rates as well but Im lifting it quite a bit with the hangers and shackle flip aready. Will that cause insane axle hop?

This is for my CC keep in mind I DO want to be able to drive on the street.
Also the springs I plan on useing are the rancho soft ride 3" lift springs I had on my blazer. While they may not be super flex monsters, I do recall them flexing enough to make the hair on the back of my neck stand up at times. In other words I feel they flex ALOT for being out of the box kinda springs.
In OTHER other words Im not so sure I need more flex than what they will give me.

Balzer
 
Last edited:
I think you are confusing 54" springs (which I have never heard of) with 56" springs (often found in 3/4 and 1 ton trucks).

These springs are cheap and easy to find, so its up to you if you think gaining a little flex and maybe having a little better ride quality is worth it (though you may have to take leaves out from the 56's).

Putting the short side towards the rear (with 56's) may cause fuel tank interference problems.

56's with a shackle flip is perfectly fine for the street. Ask mrk5 what he thinks :deal:
 
Yes you are correct just a brain fart on my part I did mean 56's. I dunno why I was stuck on the number 54. The gas tank is going above the frame so no clearnace issues. I would think 56's would be stiffer as they came in 3/4 tons as opposed to 1/2t.

Balzer
 
'95 to 2000 Tahoe rear springs are 54" I think. I don't know much else about them, but I was looking into them as possible front springs on my K5.
 
Well im just gunna use the 52's from the blazer. I was thinking about flex and spring lenth and other randome stuff today. Then I thought about the perches. I have to move the perches 2" inward on either side. Do you guys think that would make much differance on the leverage when articulating?
I dont remember the exact measurments cuz Im not that far into that stage yet. 43" wide centers and 39" wide centers gomes to mind though. Sound correct? Anyway the measurements dont matter right now. Ill go into more detail when I get to that point.

But it seams to me the further inward you move the springs the more leverage the axle would have on them. That brings me to another thought. wouldnt the shocks do better the further out you mount them? Of corse that would mean youd need even longer shocks. Seams the shocks would control better at the ends of the axle providing that was possible, so as close to the end as you can get would be benificial? Or am I just up in the night? I am not an educated man and not a physics major, but it seams logical in my head.

Balzer
 
original balzer said:
Well im just gunna use the 52's from the blazer. I was thinking about flex and spring lenth and other randome stuff today. Then I thought about the perches. I have to move the perches 2" inward on either side. Do you guys think that would make much differance on the leverage when articulating?
I dont remember the exact measurments cuz Im not that far into that stage yet. 43" wide centers and 39" wide centers gomes to mind though. Sound correct? Anyway the measurements dont matter right now. Ill go into more detail when I get to that point.

But it seams to me the further inward you move the springs the more leverage the axle would have on them. That brings me to another thought. wouldnt the shocks do better the further out you mount them? Of corse that would mean youd need even longer shocks. Seams the shocks would control better at the ends of the axle providing that was possible, so as close to the end as you can get would be benificial? Or am I just up in the night? I am not an educated man and not a physics major, but it seams logical in my head.

Balzer
Click to expand...

Why do you have to move the perches?

The further inboard the spring, the greater leverage the tire has on it. This means it will flex better and have less stability (the tire has more effect on the spring and the spring has less effect on keeping the tires where they should be).

The same thing with shocks. The further outboard they are, the more effective they are but the further outboard they the more shock travel you need.

Bottom line is to keep the springs and shocks as far outboard as possible to get the travel that you need. Moving anything inboard (on a K5) is an unnecessary compromise IMO.
 
Im moving the perches because they are differnt on the crew cab than the blazer. I assume the crew cab is the same as a 1 ton frame, even though it says its a k25.(yes K25 as its a GMC rather than a chevy) K30/35 rear axles are the same way. Im not so sure its the frame or the actual spring hangers that make the differance. But the differance is there. The frame is my guess though as its also taller bottom to top than the blazer frame.

Actualy this axle that came out of my blazer is NOT the matching axle from the K30 donnor truck when I did the 1 ton swap on the blazer for this very same reason. Just so happened the owner of the shop I did that swap at, had a 14b that fit the blazer and had matching gears. So he just traded me axle for axle. (truth be known he got a govbomb axle, and I got a open diff) I do have the 14b that fits this frame(just took it out in fact) but the one under the blazer is in better condition and Im not positive the gears match. Im willing to bet the gears match though.

Balzer

EDIT: By the way I am building the crew cab and scrapping the blazer in case I forgot to mention that.
 
I'm pretty sure that the spring pad difference from a 1 ton to a 1/2 or 3/4 ton is only 1".

In fact, I'm pretty sure my rear end is a 1 ton and I have never moved the perches with no problems (I had to relocate the shock mounts which probably means it was a 1 ton axle). Maybe I got lucky :doah:
 
Like I said I didnt take exact measurments. I dont know how you would bolt everything up. I definatly aint strong enough to flex the springs in enough to bolt them to the hangers. At least in this situation. Maybe if I did one side then used the backhoe or truck to push/pull the other side into position? Still at that it seams sketchy to bind anything up like that. Maybe Im over causious but it just sounds like square peg in a round hole. The springs bolted to the axle and rolled under the hangers the center of the spring on both sides was at the outside "ear"? of the spring hangers. In other words, had I bolted in one side the other side spring would have been outside of the hanger.

Wow I wish I was better with words.

Balzer
 
I'm reasonably sure that I'm using the 1 ton spring perch spacing (at the axle) with the stock 1/2 ton spring spacing (at the frame). This means that each spring has to "flex" in ~1/2", which really isn't that much for the bushing to take up (if you've ever had the spring hanging there without an axle attached to it, its very easy to move the spring right and left).

I can't say that I've had any issues by doing this, but if I had known the spacing was different (I swapped in the 1 tons before I was a member here) I would have moved the perches.
 
Hmm...... I did actualy try today but I was tired by then. Im fairly sure mine is closer to 2.5-3" further apart then the hangers. Tomorow is a another day though, perhaps it will be easier or better fit now that I have unbolted the axle from the springs. I havent yet desided if I want to just slap this all together for now or pinch a little and get some new parts such as spring bushings, greasable bolts ect. I am VERY broke right now as I am dumping every penny into a trucking business. So Im trying to not spend any money I dont have too. Diesel costs alot when you get 250 gal at a time, every 3-5 days. It would be nice to buy some of that kind of stuff while its all apart though. I can always go back later though.

LMAO you dont even KNOW how tempting it is to give Kert my business credit card number. But alas I have to save as much as I can until this business gets off the ground.

Whoohoo listen to me sounding all responsable and growed up.

Balzer
 
You must log in or register to reply here.

Latest Posts

Top Bottom