Getting Accurate Measurement For Front Coil After Soa

[revmaynard]

Hey guys- I need some opinions on this. I recently SOA swapped my '88 Sportruck with 95K miles (makes me believe the springs should be decent) and after measuring like I have seen instructed on the boards it only appears I'm netting 3.8'' at most if I go with a 1/2'' of sagging. I am measuring from the axle tube to the inside center of the bumpstop, if this is incorrect that could be my problem! Unfortunately it completely slipped my mind to take my own stock measurements, but I used my number off of what I measured afterwards and what the factory height should be. I'm thinking I may jack the front end up and place it on jackstands and see what I get, but I want to get the right front coils the first time!

 

Specs-

 

1988 4wd

Dana 35 to SOA 8.8

I measure about a 1/2'' of height from the tube to the spring perch.

Factory 4wd leaf springs

 

 

Any input is appreciated!

[Eagle]

I measure about a 1/2'' of height from the tube to the spring perch.

???

 

You might want to check that measurement.

[Eagle]

 

I measure about a 1/2'' of height from the tube to the spring perch.

???

 

You might want to check that measurement.

 

And if you gained only 3-1/2" of lift with a SOA conversion, your rear springs are NOT in good shape.

[revmaynard]

You're right, I typed the wrong thing from my note sheet. It is 1'' from the top of the tube to the resting spot of the spring on the perch. I never said they WERE good, only that I assumed they were given the low mileage. This truck sat for a little over 10 years without being driven so I didn't think they would be too bad off. My thought is the downward rake from not lifting the front (IE: needing to measure for coils) is possibly compressing the spring at the front skewing my numbers. I won't have a chance to check this again until the weekend and just wanted to get some input and see if that seemed to be the reason.

[revmaynard]

This just looks like a LOT more than that even on stock tires.

 

 

[Eagle]

You're right, I typed the wrong thing from my note sheet. It is 1'' from the top of the tube to the resting spot of the spring on the perch. I never said they WERE good, only that I assumed they were given the low mileage. This truck sat for a little over 10 years without being driven so I didn't think they would be too bad off. My thought is the downward rake from not lifting the front (IE: needing to measure for coils) is possibly compressing the spring at the front skewing my numbers. I won't have a chance to check this again until the weekend and just wanted to get some input and see if that seemed to be the reason.

I have no idea what you're talking about or where you got your measurement points. The Jeep Information Service Bulletin (which has been cited in multiple previous threads) tells us that for the front you measure from the top of the axle tube to the underside of the frame rail directly above. For a 4WD vehicle, the measurement should be 7-3/4" +/- 1/2".

 

As to the rear lift, think about what you're gaining. The amount of lift will be the axle tube diameter + the offset of the spring perches from the tube + the thickness of the spring pack. That's going to be between 5-1/2 and 6 inches. Are you measuring to the bottom of the actual bumpstop? If so -- wrong. There are four different bumpstop heights. You measure from the top of the axle tube to the bottom of the frame rail AT the bumpstop. The dimension (for stock) should be 9.2" +/1 1/2". With a spring over conversion, I would expect something on the order of 15 inches.

[revmaynard]

I am measuring just as you described at the very end which is what I took from the thread below by a member named Hornbrod.

 

http://comancheclub.com/topic/13565-stockfactory-overload-or-helper-springs/page-2?hl=helper%20leaf

 

When I was last measuring I was seeing at most around 12.5-13'' at most depending on if I account for a 1/2'' of sag or not. Thanks for the input so far because I was expecting about the same using that method. Maybe I'll see what I get when I jack it up this weekend and remeasure.

[Incommando]

My SOA with 2wd springs netted me 5" of lift measured the "correct" way. That is with well worn 2wd springs and Barnes spring perches. I used 5.5" RE springs for the front to get rid of some of the rake.

Front RE 5.5" Springs                                                                                                          $87

http://mudflaps.com/...-zj-4-pair.html 

[Zgerkhart]

My SOA with metric ton springs put up about 7-8" of lift. I also used 5.5 RE front coil but I also had to put 3" spacers to level out.

[GrizzzzBear]

I had done the SOA, have a Custom Lower Shock mounting plate, and a wedge.

My gain was 6-3/4 inches

Now I am going to the Metric Ton Springs, with an extra 2 inch curve.

I should get another 3-4 inches lift.

As long as I figured it right, I should have about 10 inches lift in the back.

I have the stuff to go Long Arm with 10 inches lift in the front.

Then I will need to get new donuts. 35's or 37's

I gotta check the "Legal Height" but, I should be good

[zackcj7]

The crappy part is even if you get an accurate measurement the springs you buy may not give the lift they advertise.