Crashsector
NAXJA Forum User
- Location
- Annapolis, MD
Evening,
This is our victim, my 1989 XJ. 197,600 miles - purchased for $500. It had a pretty good case of butt-sag when I got it. Overloading it with about 600 pounds of firewood didn't do any good.
Initial measurements gave me 29.5 inches from the ground to the bottom of the rear fender flares.
Yea, this thing's been bottomed out a few times.
The proper fix: replace the leafs. After considering dealing with rusted U bolts, shackles, shackle bolts, etc., and weighing my total investment in the Jeep, I opted for a quick-and-easy solution. I purchased the Husky Springs LP4 Helper Spring set from Rock Auto for $85. Best solution? No. Cheapest? Probably. Easiest? Definitely.
The first thing that struck me is the thickness of the springs. These things are massive!
The directions say to place them up against the spring perch on the rear half of the springs. This is how it sits:
Two things began to worry me.
First: the spring looks like, under compression, it would be resting on the strap holding the leafs together:
The second is that is looks like the lifted end of the spring may contact the skid plate and frame rail:
I decided to see how everything shakes out and started bolting things up. Here we are with the first set of nuts tightened down:
The instructions suggest two different amounts of preload: 1/2" from the sprung end to the end of the bolt for loads under 800 lb, 1.5" for loads over 800 lb. Since I can't tell what I'll be dealing with, I went for the latter. This is the clearance to the strap with the axle under weight:
Oh well. One strap is already broken, if I have to take them off it will be 5 minutes with a screw driver and a hammer.
I lowered everything back on the ground and this is the result:
Same measurement as before yields 31.5". I'm stoked. Time to test drive.
What a difference. This thing morphed from a Cadillac into a Jeep. Huge increase in ride quality, responsiveness, and huge decrease in body roll. The back is probably a bit too stiff, but seeing as this will be a mobile tool box and boat hauler it's probably for the best.
My worries about clearance crept back up when I got back home from the test drive. It looks like both sprung ends are catching on the skid plate and are actually resting on them under the weight of the Jeep.
The instructions say the rotation in the second photo is normal, but that interference is not. I think if this install was on springs that weren't sagging as badly it probably wouldn't be a problem. Taller shackles in the rear would probably help too.
I could grind away a small area of the skid plate for clearance, but then I feel they would bottom out on the frame rail, something I'm not enthused about.
Anyone have any suggestions as to what to do? I'm going to take those straps off tomorrow and see if that makes any difference. I don't want to take any material off the springs as that end is pretty narrow as it is.
Thanks for all the help and I appreciate any suggestions!
--Andy
Annapolis, MD
This is our victim, my 1989 XJ. 197,600 miles - purchased for $500. It had a pretty good case of butt-sag when I got it. Overloading it with about 600 pounds of firewood didn't do any good.

Initial measurements gave me 29.5 inches from the ground to the bottom of the rear fender flares.



Yea, this thing's been bottomed out a few times.
The proper fix: replace the leafs. After considering dealing with rusted U bolts, shackles, shackle bolts, etc., and weighing my total investment in the Jeep, I opted for a quick-and-easy solution. I purchased the Husky Springs LP4 Helper Spring set from Rock Auto for $85. Best solution? No. Cheapest? Probably. Easiest? Definitely.

The first thing that struck me is the thickness of the springs. These things are massive!
The directions say to place them up against the spring perch on the rear half of the springs. This is how it sits:

Two things began to worry me.
First: the spring looks like, under compression, it would be resting on the strap holding the leafs together:

The second is that is looks like the lifted end of the spring may contact the skid plate and frame rail:

I decided to see how everything shakes out and started bolting things up. Here we are with the first set of nuts tightened down:

The instructions suggest two different amounts of preload: 1/2" from the sprung end to the end of the bolt for loads under 800 lb, 1.5" for loads over 800 lb. Since I can't tell what I'll be dealing with, I went for the latter. This is the clearance to the strap with the axle under weight:


Oh well. One strap is already broken, if I have to take them off it will be 5 minutes with a screw driver and a hammer.
I lowered everything back on the ground and this is the result:

Same measurement as before yields 31.5". I'm stoked. Time to test drive.
What a difference. This thing morphed from a Cadillac into a Jeep. Huge increase in ride quality, responsiveness, and huge decrease in body roll. The back is probably a bit too stiff, but seeing as this will be a mobile tool box and boat hauler it's probably for the best.
My worries about clearance crept back up when I got back home from the test drive. It looks like both sprung ends are catching on the skid plate and are actually resting on them under the weight of the Jeep.


The instructions say the rotation in the second photo is normal, but that interference is not. I think if this install was on springs that weren't sagging as badly it probably wouldn't be a problem. Taller shackles in the rear would probably help too.
I could grind away a small area of the skid plate for clearance, but then I feel they would bottom out on the frame rail, something I'm not enthused about.
Anyone have any suggestions as to what to do? I'm going to take those straps off tomorrow and see if that makes any difference. I don't want to take any material off the springs as that end is pretty narrow as it is.
Thanks for all the help and I appreciate any suggestions!
--Andy
Annapolis, MD