Matt here, new to the forum. Have a 2001 Cherokee w 4WD, in good shape, but rear leaf springs are flat and rusted, was thinking that would be my first move to tighten up the ride. Replaced shocks a while ago, but that's about it underneath. I avoid any hint of potholes/bumps if I can, would like to start addressing that.

I do minor work on it, but have a mechanic who will install parts I buy when its beyond me. Any advice on leaf springs? What to get and where? Thanks - M

 

If your vehicle is stock, you would consider a stock style replacement spring set, all the old ones have flat springs so a new set will level the truck and improve handling

Decide upon stock rubber or poly mounts

Removing the spring eye bolts can be very difficult, as; they have factory loctite, get rusty on the weld nut which is inside the frame, and may rust to the steel inner sleeve of the bush

So its best to soak penetrant by spraying inside frame well ahead of time, and have heat, preferably oxy, on hand to heat the bolt ends (take fire precautions, penetrant is flammable)

I have changed several sets, no oxy. If you are patient it should be a relatively straightforward task. You do not want to break off the weldnut inside the frame, as repairing that is nasty

Do bear in mind the XJ is not the nicest vehicle to drive over bumps, especially unladen in the rear

You make me diverge ('70's Jaguar XJ ) independent rear suspension units soak up road bumps better than any other vehicle I have ridden in...still !

I have a 3.54 Track lock unit complete, and would love to shove it under a Jeep XJ.

They have a Dana 44/Salisbury gearset, inboard disc brakes, 4 shock absorbers in coil springs and are a very tough unit.

I have seen older pickups with both Jag front and rear suspension units, sorry for diversion, I will start a thread in Modified section

 

That Jag IRS was, probably still is, great & found itself under anything & everything [when rotten/front ended Jag'wahs were 2 a penny (i.e. a dime a dozen)] but, oh boy, those inboard brakes were a pain!
Now back to reality, my approach to changing rear springs is to do it in easy stages over an extended period: treat each bolt, + the U-bolts on each side as separate jobs, remove, clean, grease & replace them. That way, if one takes 1/2-day you don't feel suicidal because the clock is ticking & there's still so much left to do, 'cos you've achieved that evening's/day's/weekend's objective. Then, when you actually come to do the job, you know it will all just come apart, no sweat, no problem.

One final tip, if you don't have the luxury of a lift, &/or an industrial rattle-gun, radius the pinch weld in line with the head of the front bolt, then you can use a socket on a 10" extension supported on a jackstand & you can swing that 3' breaker bar, even, literally, put your shoulder to it, outside the body, rather than trying to apply the effort required in a confined space while in an awkward position.

 

Thanks for the feedback! I'm looking at Crown, Dorman Omix - just want to purchase good stock replacement leaf springs, get it back to when it came off the lot back when.

Any opinion among those? And is there anything else (shackles, etc) that is typically replaced along with springs after 20+ yrs? Thx - M

 

depends what has been changed out, but my experience has been that most of the suspension components needed replacing, just do what's obviously needed by physical inspection first. I would do shackle bushes

 

Can't help with brands because, while familiar with the big American names (& some of their reputation) here in the UK we, mostly, have to grab what's going.

As for other parts, awg's right - physical inspection's king but spring bushes (yeah, I know, you call them bushings) for sure 'cos however good they are, chances of removing them and refitting them are slim. b-t-w, they're not cheap, so well worth paying a bit more if they're included - & if they're fitted, even more so.
Be surprised if you needed shackles, but upgrades are something else again.
Be prepared to replace at least some of the bolts, but no need to pay fancy prices, any 1.2-decent hardware store (or A TSC type place) should have what you need.
Some say new U-bolts but if they're still undamaged once removed I say just get new nuts, as re-using Nylocs is not best practice (although I've got away with it all my life).

 

Thank you!

 

I have replaced the leaf springs in 2 xj's so far. I used the Crown heavy duty springs each time. You can pick them up on amazon for about $100 per side. You will also need the bushings. The springs are used to duplicate the "up country" lift in the back as they will pick it up about 1.5 to 1.8 inches over stock. Other then squeaks, I love them. Remember that after you lube the bolts that are going to have to be removed you will need heat as well. I think all 4 spring eye bolts are locktighted in with the red variety. Good Luck!

 

Thanks Sig, I will take a look at the Crowns again. I had pretty much decided on:
- Dorman 929301 rear leafs, with bushings already in
- Dorman 722024 shackles (hardware included)
- Rubicon Express RE2421 Rear U-Bolt Kit for Jeep YJ/XJ

I'm guessing I will need some bolts for the leafs in addition to the U bolt kit.
Anything else you think I'll need? AWG mentioned "stock rubber or poly mounts", but I think he's referring to the bushings?

I guess the Crown's worked for you fine. Looking around, I found they were rated pretty equal to the Dornan, but I'm listening if you think otherwise. I just thought the bushings already in place was a point in favor.

 

"Dorman 929301 rear leafs, with bushings already in" - I'd find that very persuasive (all other things being equal, or even close)

No, I'm not sure what awg means by mounts, in his post he says "bushes" which is what you call bushings.

Personally, I wouldn't assume I'm going to need U-bolts - & I'd want to know exactly what's in a "kit"

 

As already mentioned getting the spring eye bolts loosened can be very difficult and is the hardest part of this job. I did it myself on my relatively rust free '91 and was successful in not breaking anything. The captured nut inside the unibody member/ spring box is the highest risk area. This is at the forward spring mount position. You want to get penetrating fluid inside the bushing sleeve (where the bolt passes through the spring bushing) and at the hidden nut that is welded to the spring box. The photo below shows the setup on my ’91 after new springs (Old Man Emu – very good but more expensive) were installed and coatings touch up done. Location of the nut is circled.

Assuming you have the original factory setup there is locking compound on the bolt threads where it goes into the hidden nut. Heat will help soften the locking compound but as you can see it is difficult to get enough heat at the right place on the forward spring mounts. I did not use heat as I didn't have an oxy acetylene torch, did not want to burn off paint and I had applied a lot of penetrating fluid over a couple of weeks creating more risk of fire.

Even if you have someone else do spring replacement start by applying penetrating fluid for several days. Kroil penetrating fluid might be a good choice or ATF mixed with lacquer thinner is effective. Get the weight off the suspension on the side where you are working to help relieve forces on the bolt. Without heat it took a fair amount of force to break the bolts loose. You will hear a cracking sound. Then work the bolt back and forth slowly a small fraction of a turn at a time. I would hesitate to take this job to someone that will be in a hurry and carelessly apply an impact tool to the bolt. There is a good chance the welded nut will break free. If that happens there is a lot of work to repair it and none of the options are great. You will find info with regard to this by search on this forum.

I recommend using original equipment spring bolts. A couple of years ago I obtained mine from a local Chrysler dealer parts department at a reasonable cost. They have the proper strength and come with locking compound already applied. If this is your daily driver I would wait until you have alternate means of transportation lined up. If something goes wrong it could take some time, and money, to correct.

Closeup of spring box and location of hidden, welded in place nut



Overall setup

 

Yes, it's a job that can all too easily go pear-shaped &, at best, take much longer than it should. That's why I suggest treating each bolt as a single job, then putting them back with plenty pf lubricant, so when you actually come to replace the spring, you know it will all come apart.

As for bolts, I got mine from my local fastener specialist (our hardware stores aren't like yours) the were pennies, rather than £/$'s. A HT bolt is a HT bolt, it's what it says on the head that's important, not where you bought it.

That said, I've not needed them because the only one a had a problem with was a back one, because the shackle-box had rusted away & I had to cut the nut off the bolt. Fortunately, I had a spare, because I'd practised on my parts XJ.

 

Thank you, third coast, I will certainly keep this in mind! I'm going to a shop with the parts to do the switch out, I don't have the tools for this job. Might just show them this post and pics to emphasize the prep work.

Looks very nice, btw! - M

 

Ideally you want to use specified OEM fasteners for all suspension applications due to performance and safety factors. Automotive suspension fasteners are designed for specific application requirements of quality, strength, form, elongation, etc. and do not necessarily correlate to standard SAE or metric fasteners. I appreciate the difficulty in locating parts for vehicles outside of their country of origin. You were smart to use a high tensile (HT) bolt and fortunate to have a good fastener supplier available to you.

For my XJ the original Jeep part number for the leaf spring and front control arm bolt is 34202118. It looks like the same or similar bolt was used from ’84 to ’01. For those in North America original Jeep suspension bolts are still available from dealers and on line Chrysler/Mopar parts suppliers. Crown also has the same or equivalent part but you may find the Mopar bolt for less. Amazon currently has offerings for Crown and OEM Mopar bolts.

If you must substitute obtain a flange head metric class 9.8 bolt. This class is less common than readily available metric bolts. It roughly corresponds to an SAE grade 5+ bolt. If you can’t find 9.8 its probably best to go up in class, such as 10.9, versus down in class. If available an AN or NAS aerospace rated fastener would be the best substitute. Using washers or just a standard hex head instead of a flange head bolt is not a suitable substitute for critical applications.

Below is a photo of an OEM type bolt I removed from one of my leaf springs. You will see unique features including black oxide coating (effects properties), the larger diameter of the shank near the head where the bolt pilots through the spring box, lack of threads on half of the length and the reduced diameter on the end to help engage a blind nut. Also note the flange on the head to reduce localized stress and the generous radius where the bolt shank meets the head to help minimize fatigue from bending loads. There are cuts across the first few threads to help clear debris at the bolt to nut interface. It is not your typical hardware store fastener for good reasons.

 

Great advice here. Treat each bolt as a separate job. When I did mine, it took me 3 days to do the passenger side. Everything was rusted, the nut broke away from the frame so I had to cut an access point. The bolts were so rusted, I cut the leafs off with a grinder, then removed the bolts. To my frustration and surprise at the same time, when I did the driver's side it took 30 minutes total. Nothing rusted, no broken welds, no problems at all.