Life span of coils and springs

[honesT]

I have a 1996 Cherokee XJ Country that has no tow hitch and was pampered before I bought it.

I need some of your knowledge reguarding what the average life span of the front coils and rear leafs are, not including Jeeps that have been towing alot and jumping off cliffs

How can I tell if the coils & leafs are ca-put ?

Thanks in advance for your time, rest assured I will pass on what I learn to others so your time won`t be waisted

 

[98NWCherokee]

My 98 2wd XJ has only seen pavement. It has 150k on the original suspension. The front coils are fine, but the rear leafs are sagging. It's been on my "to-do" list to swap out for awhile now, but the ride is fine and I have no issues with handling or safety.

 

[cj5wagomando]

I would think you would need bushings long before new springs.

 

[Tim_MN]

Springs either sag or fail. The cause can be mileage related, use/abuse, or quality issues from the manufacturer.

Measure the static height of the springs and inspect the leaf springs for leaf deformation and breakage. Leaf springs should have a smooth continuous curve with no flats or reverse curvature.

Stock Cherokees are 17.5" front and 17" rear when measured from the center of the rim to the bottom of the fender flare.

 

[Bronco]

Contrary to what I have read here and other places, springs do not "sag" over time, they are bent from exceeding their design limits. Steel has an elastic limit and a fatigue limit. A spring that is used within those two limits will last indefinitely. In other words if your springs are bent further than they were designed to even one time they will not return to the previous shape. They will be deformed or yield or take a set… all terms for the same thing.
The following is not fact but my belief based on observation: Most stock XJ rear ends “sag” from degradation of the bump stops that does happen over time. As the bump stop fails it lets the axle move too far and the spring is damaged. Also if you add a lift without lowering your bump stops the spring is left unprotected from overload. The twisting of extreme wheeling I think also causes many lifts to “sag” because the steal is over stressed locally. I think it’s the twisting that results in the main leaf getting all wonky right at the frame side bushing.

 

[Tim_MN]

Yes, failure to properly bump stop any leaf spring will allow it to over-flex which usually ruins the spring.

Stock Cherokee leaf springs are notorious for sagging even on grocery getters that do not tow, haul excessive cargo weights, or even leave the pavement. Poor design parameters or inferior quality spring steel would by my guess for the cause of Cherokee spring issues.