How do you measure lift

[thistle3585]

I just bought a Jeep and I am curious how you measure the height of the lift? I am assuming that larger than stock tires don't go in to the figure, so it wouldn't do any good to measure from the ground. I am trying to figure if there is any lift on my Jeep before I invest in new springs and shocks.

 

[SrBeaver]

Best way to get close is from the top of the axle tube to the bottom of the frame.

 

[thistle3585]

Thanks, but what would that dimension be on a stock vehicle so I could figure how much lift I have?

 

[Manhattan]

It's really tough to figure out with a tape measure. These trucks are 30ish years old - a lot can happen in that time, e.g. springs have sagged, non-stock shackles. As odd - and nonscientific - as it sounds, your best bet is to post a side pic of the Jeep and a pic of the shackles (include the tire size and amount if any body lift) and see what the consensus opinion is.

Springs really only came in 2.5", 3", 4" and 4.5" - the 4.5" being R.E. and they're pretty easy to I.D. On that... measure the width of the springs. And - probably before any of the above, inspect the springs for any markings, e.g. brand, part number, etc. While you're inspecting, the springs, see if you can I.D. an add-a-leaf. They're usually pretty easy to spot. If you're unsure, post a close-up of the spring pack.

 

[thistle3585]

Then let me ask this question..... Do I need to worry about what springs I put back on my Jeep? The ones on there now are pretty much flat and in really bad shape. The PO included some used replacement springs in the deal that he was going to put on but didn't get a chance. They have the same number of leafs, so I have to believe that I'll be okay but I'm concerned that I am going to put something different on there then have that problem compound itself in the steering or something else. I'd like to replace the shocks while I am at it, so I am guessing that will take care of itself. I will try and get some photos taken.

 

[Manhattan]

Then let me ask this question..... Do I need to worry about what springs I put back on my Jeep? The ones on there now are pretty much flat and in really bad shape. The PO included some used replacement springs in the deal that he was going to put on but didn't get a chance. They have the same number of leafs, so I have to believe that I'll be okay but I'm concerned that I am going to put something different on there then have that problem compound itself in the steering or something else. I'd like to replace the shocks while I am at it, so I am guessing that will take care of itself. I will try and get some photos taken.

Hard to say without knowing what the two sets are. We could tell a lot from a pic, e.g. arch, military wrap, banding, etc, but it's still going to be tough to say for sure - spring rate being the biggest guess if they're truly unknown brand/model.

At a minimum, pull a tape on the springs from eye-to-eye and eye-to-pin-to-eye. The pin locates the axle. CJ springs are symmetrical - in that the pin is centered end-to-end.

What's the problem that could be compounded - that you ref'ed in ^ post?

 

[thistle3585]

I phrased that wrong. It wouldn't be compounding an existing problem but wondered if it would create a new one. As I understand it, if I ended up putting springs on that were "taller" then wouldn't I need to do some sort of an extension on the steering shaft and/or the drive shaft to account for a difference in height?

 

[Manhattan]

I phrased that wrong. It wouldn't be compounding an existing problem but wondered if it would create a new one. As I understand it, if I ended up putting springs on that were "taller" then wouldn't I need to do some sort of an extension on the steering shaft and/or the drive shaft to account for a difference in height?

Not necessarily. If you swap in 2.5" lift springs in place of stock springs, nothing needs to be changed other than springs and shocks. Actually, you can get by with stock shocks for a while too. If you go to 4" springs, you'd need to add extended brake lines (a cheap upgrade too) and a drop pitman arm - the "lever" that connects the steering gear to the drag link.

Now, I'll agree - 4" springs do somewhat open up a small (but commonly addressed) can of worms. For starters, that drop pitman arm will result in a steering wheel that's no longer centered/straight (9 and 3 are now 11 and 5), and you'll have slightly less turning radius... on one side. You didn't mention if your Jeep is a 5, 7 or 8. This matters believe it or not. A CJ8 can handle 4" springs without any driveline issues. A CJ5 would require shims to rotate the pinion/axle a few degrees to reduce the angle the U-joint is at. But that opens another can - the Transfer Case to drive shaft angle and the axle to drive shaft angles have to be the same or you'll get a vibration.

But ALL of the above has been addressed thousands of times - no new ground you're breaking here... that's good news.

 

[thistle3585]

Actually, I don't want any lift. I want to try and stay as close to original as possible. Its a 78 CJ5 .

 

[Old Dog]

check out this thread http://www.jeep-cj.com/forums/f19/determining-lift-height-11160/