Xj Spring & Weight Specs?

[Eagle]

Trying to decide what route to take to bring a 2001 XJ up to where it should sit. New front coils are Up Country (bought new from dealership) and the front sits at exactly 18". So far ... so good.

 

The rear sits at 16" ... which is a full inch below where it should be. Everything is so rusted underneath that I don't want to risk breaking a weld nut loose, so rather than swap the rear springs entirely, I'm looking at doing a bastard pack. I have leaf springs around here from YJ Wranglers, XJs, and MJ. I'm trying to decide between adding one leaf (making it a 5-leaf spring) or two leaves (making a 6-leaf spring). I found a decent on-line spring rate calculator, but I need better input.

 

1. Curb weight for an XJ is around 3350 to 3400 pounds. Does anyone know how that's distributed, front to rear? For front engine, rear wheel vehicles I typically assume it's about 60% front and 40% rear, but I wouldn't mind more accurate figures if anyone has them.
2. What's the length of the XJ rear springs, eye-to-eye?

[HOrnbrod]

can't help with the XJ weight distro, but here are the rear leaf specs:

 

http://www.generalspringkc.com/Leaf_Springs_Jeep_Cherokee_s/1953.htm

[Oyaji]

Barring anyone being able to provide factory figures, you could always take the empircal approach: weigh each end and calculate the ratio yourself.  A couple years back my local Farmer's Co-Op charged me $3, which included a printout; there might be similar alternatives nearby for you, like maybe a ready-mix concrete vendor, for instance. (At the time I had thought of weighing each axle but passed on it - now I wish I had, so I could offer you the info. Sorry 'bout that  :( )

[dave92cherokee]

Are the rear springs flattened out or inverted? If they're not and you currently have a smooth ride with them maybe you should look into the shackle relocation brackets which give around an inch of lift and give the ability to control the shackle angle. All that's taken apart is the rear shackle mount bolt which shouldn't be to bad rather than taking the entire spring out. Here's a link to them and they're made by one of the guys on NAXJA and have received alot of good reviews about them.

 

http://www.hdoffroadengineering.com/collections/frontpage/products/xj-shackle-relocation-kit

[Eagle]

Are the rear springs flattened out or inverted? If they're not and you currently have a smooth ride with them maybe you should look into the shackle relocation brackets which give around an inch of lift and give the ability to control the shackle angle. All that's taken apart is the rear shackle mount bolt which shouldn't be to bad rather than taking the entire spring out. Here's a link to them and they're made by one of the guys on NAXJA and have received alot of good reviews about them.

 

http://www.hdoffroadengineering.com/collections/frontpage/products/xj-shackle-relocation-kit

 

Thanks, but I'm not interested in screwing up the suspension geometry. This XJ is my daily driver. Besides, you apparently missed this part:

 

Everything is so rusted underneath that I don't want to risk breaking a weld nut loose, ...

 

I have an intact pair of mid-90s XJ springs that were take-outs when one of the guys in NAXJA-NAC lifted his. I think what I'll do is cut the eyes off the main leaves on those, then remove the lower three leaves from my spring packs and put the full four leaves from the donor springs in. If that doesn't get me all the way to the 18" it should be, it'll still be a lot better than it is now.

 

I was considering adding a sixth leaf, but I suspect that will take it too high.

[mvusse]

Don't forget that adding leafs makes the pack stiffer. Since this seems to be a daily driver, you probably don't want to make it ride like a dump truck. If you have access to Comanche leafs, you could make a bastard pack with the XJ main leaf and one other leaf combined with two Comanche leafs for still a total of 4.

[mvusse]

Despite what they say about improving driveshaft angles, this will actually make the driveshaft angles incorrect causing vibration. A lot of lift part manufacturers either don't know or don't care about the physics behind driveshaft angles and u joints.

 

Are the rear springs flattened out or inverted? If they're not and you currently have a smooth ride with them maybe you should look into the shackle relocation brackets which give around an inch of lift and give the ability to control the shackle angle. All that's taken apart is the rear shackle mount bolt which shouldn't be to bad rather than taking the entire spring out. Here's a link to them and they're made by one of the guys on NAXJA and have received alot of good reviews about them.

 

http://www.hdoffroadengineering.com/collections/frontpage/products/xj-shackle-relocation-kit

[Eagle]

Don't forget that adding leafs makes the pack stiffer. Since this seems to be a daily driver, you probably don't want to make it ride like a dump truck. If you have access to Comanche leafs, you could make a bastard pack with the XJ main leaf and one other leaf combined with two Comanche leafs for still a total of 4.

 

The springs in it now are very soft ... so soft that my wife complained about how she almost got seasick when she rode in the back recently when driving relatives to the airport. I've done the extra main leaf AAL before and the ride is very comfortable. The result is also fairly predictable. Doing a mixed pack with MJ springs would be completely unpredictable, and mixing leaves with greatly different native arch is never a good idea.