springs and shock for the no-lift guys

[streetpirate]

ever wanted your street driven xj to be tighter in the corners? me too. im gonna try to do mostly junkyard upgrades. im looking at t-bird coils up front, that are cut down, and adding a leaf or two in the back. i know i need new shocks, but i have no idea which ones to get. I'll make sure to do a good write up and photos. im doing poly bushings real soon, still need to get poly sway bar bushings front and rear.

i want questions opinions suggestions

 

[5-90]

The idea of swapping springs is fine, but watch out when you cut coils. It might be better to have a spring shop modify them for you.

Ever see some kid in his Honda bouncing along in a parking lot, or on a clean level road? That's cut springs - run over a dime, and it takes you five minutes to settle down. Cutting springs can change the "spring rate" drastically (spring rate = amount of weight to compress a spring a given amount, usually expressed in pound-inches) and could result in an unstable vehicle.

Just thought you ought to know.

5-90

 

[Ed A. Stevens]

If you plan cutting coils I would begin with a set of stock springs. They are usually easy to find, and if they are from a friend's lifter XJ they are usually free. Consider it a free exercise to learn how spring changes work.

Cutting a coil will increase the spring rate.

A helpful link to indicate the spring rate change can be found here at one spring rate calculator

Start with the stock spring specs, and then model one less coil (or two less coils, etc.). A stock spring is something like 0.5625 (9/16" wire), in a 5" OD coil, with 11 coils. Plug it in and you get ~150 #/in.

Cut one coil, change the coil number to 10 and you increase the rate from ~150 to ~160 #/in. Cut two coils, from 11 to 9, and you get a rate of ~180 #/in. Work with the modeling tool to predict what you will get.

Old Rancho 3" lift coils are larger (5/8") wire and will provide a stiffer rate with less cutting (they start at 0.625, 5", & 11 coils = ~230 #/in without cutting). These coils are usually cheap and were common on road/rally XJ's.

The stock coils and Rancho coil free lengths are ~18".

You also need to try and keep the spring loaded and contained at full extension (like when flying over a bump, with a shorter free length spring). Limit straps or short shocks (at a minimum) will help keep the coil from falling out of the mounts.

If you do want to cut a coil use a cut off blade in a chop saw or angle grinder (or a cutting torch).

 

[streetpirate]

any advice on the progressive rate t-bird coils? would cutting the bottom keep the same initial rate and give a firmer rate with compression?

 

[rsalemi]

Just for reference; here is my setup- 89 with 284 stroker.

ZJ upcountry front springs, Doestech 3000 front shocks, 1 1/8" front sway bar with energy suspension poly bushings.
Rear trailer tow 240 lb leaf springs, poly bushings, & Edelbrock RSK rear shocks, Poly rear sway bar bushings and BFG 255X60X15 TA's on 8" canyon rims.

This combination will go pretty fast on most roads. The ZJ fronts are already pretty stiff at stock legnth - cutting them would make them stiffer as ED says.

 

[raypla]

I too have the Edelbrock IFS shocks (only suspension upgrade) stock height and I can take corners, that I used to take at 35, at 50-60. They also improved the ride drastically, and have poly bushings. I was going to upgrade the swaybars to poly bushing units
My saggy rearend to Rock Lizard BB kit check it out,
http://www.rocklizardfabrications.com/lizard_lift_kits.htm
It comes w/all this good stuff,
Rock Lizard Cherokee 2" Add a Leaf kit includes:

(2) Heavy Duty Progressive Rated Coil Springs

(4) Long Add a Leafs with No-Squeak Pads

(6) Leaf Spring Clamps

(2) 5/8" Center Pins

(4) U-Bolts

 

[purplexj]

I had my front coils cut on my 1971 Ranchero and the ride was horrible. One spring fell out once. Even w/KYB's (the hot ticket 20 years ago). Went w/Moog HD springs and the ride was great. Looking for a 2.5 4spd 2wd mj for back up work truck and was looking for info on better handling, and pos 1 or 2 inch drop. 1" front 2" bigger rear sway bars, poly and shocks. My old 92 2wd, 5spd XJ dd now has 3.5" lift 31 4wd and i got rid of my 99 E150. The back truck won't get used much work, just want something more MPG friendly and easy to park. Would TJ coils lower XJ. Was thinking of lowering blocks in rear or is there a better shackel. Stock parts should be easy to get my friends own a junk yard. You should see the XJ stuff they throw away , sometimes the stuff falls into my van.


b's

 

[rsalemi]

purplexj TJ 4 cyl front coils will lower the MJ front by 1" - 1 1/2" and XJ shackles will drop the rear by about 1/2".

 

[streetpirate]

i dont get it, my stock height xj only has 2" clearance from the bumpstops, and less than that from the uca mount to the edge of the oilpan and tranny lines on the passenger side. but then again, i have reverse arch on my leaves. (dont think thats stock)

 

[ROBZ95Xj]

i dont get it, my stock height xj only has 2" clearance from the bumpstops, and less than that from the uca mount to the edge of the oilpan and tranny lines on the passenger side.

It seems that thsoe 2 don't get along, here a pic of my punctures cooler lines due to to much suspention uptravel.

 

[krakhedd]

Hey, that pic is nice. I managed to do that with stock suspension once, but it was a LOT worse..........

Ok, onto the question. If you're going JY parts, this won't work, but why not get a set of airbags? I dunno how much snow you get in Oregon, but the best way to get through snow doesn't have so much to do with 4wd as it does with having ground clearance.

I'd also convert to coil-over for the rears, get shorter & stiffer springs, so you can lower it a bit more. There's also little/no point in retaining the 4wd, so long as you've got some kind of locker rear and don't go offroading. Converting to RWD would save you a couple hundred pounds (I think), and an added benefit would be no revolving mass in the front axle (improved gas mileage).

 

[bjoehandley]

I almost did that stock too, but that was after CarMax replaced the line under warrenty and ran them wrong way.........

 

[xjgrn]

Lots of luck turning the Xj into a sporty handling car.You might have some sucess, but the fact is,solid front axles arent the way to go for carlike handling.Before you do anything, think about going to a Blazer. Ifs is the way to go for what you're looking for.

 

[streetpirate]

ACK no blazers. i dont think its getting lowered, and im keeping 4wd. most snow ive ever had (HAD) to drive in to get home was less than eight inches. i know there are alot of improvements to be made to the xj in the handling department, but i know its not a sports car. what it IS is the perfect all year daily driver.

 

[streetpirate]

Just for some clarity, i have no intrest in lowering my jeep. i just want a MAX of 2" lift. thats why i want to cut one coil off the tbird springs, and make a slightly stiffer than stock bastard leaf pack.

 

[bjoehandley]

Right now both Dad and I have Rancho RS500's on the front, Napa/Tennecco Airshocks on the back, 235/75/r15 Wranglers (he's got AT's and AT/D's I've got Silentarmors) on factory rims and both trucks will do suprisingly well if needed although I'd like to try some urethane sway bar bushings eventually.

 

[purplexj]

rsalemi Thanks for the infoon TJ coils, but i'm only trying to level ride and make it a shorter lift to load equipment. I have a 05 Astro for work but will use the MJ for night work one or two times week and Home Depot runs. By the way my Xj handles great w/the 3.5 lift it has.

 

[krakhedd]

I think my XJ will handle just fine with new shocks (mine are totally shot) and poly bushings all the way around. Only later *MAY* I build a street XJ, but that would be a project vehicle which gets torn apart and rebuilt for that purpose only.

Besides, I more need an all-purpose vehicle for now. I can buy/build a street vehicle that doesn't weigh as much, is set up already more for handling, etc. when I get the money, and this would be a much better base to start building a vehicle for the purposes of going fast and handling.

 

[Boomer]

"Up Country" suspension had higher spring rates.

 

[streetpirate]

AHHHH! RUN AWAY FROM THE ZOMBIE THREAD!