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RE 4.5 spring problem?

moparcyco

NAXJA Forum User
Location
Preston Idaho
Hey guys just installed a set of RE 4.5 springs to my 91 2 door.Went through the usual problems with broken weld nuts and all that goes with that.Anyway I get everything back together go to pull it out of the garage and it feels like the wheels are wobbling.So I have my wife drive i up and down the driveway and watch it looks like the leafs are bouncing up and down?I tried this with the shocks hooked up and not.You can't even go 2 or 3 miles an hour! it bounces so bad WTF!I can easily bounce to rear with one hand.Used brand new bilstein 5100"s.Doesnt matter if the shocks are connected or not.Had to just walk away never had a project kick my junk like this.Please what is going on here?

The springs can only go one way right?Have I overlooked something simple?I am fairly new to the world of jeeping,but not wrenching please help before I pull whats left of my hair out.:helpme:
 
This is happening on the rear only? Is it a full pack or an add a leaf and lift shackle? The center pin is offset, the short side of the spring should be to the front although I doubt you would've put it in backwards because it would've pushed the rear back alot. Did you tighten up the bolts with the jeep in the air or on the ground with the weight on the suspension? How's the shackle angle look?
 
It's gotta be the shocks, doesn't it? If they're connected, (and working at all,) this kind of bounce should be impossible . . . Right?
 
Did you set it on the ground and tighten the shackles up?, they shouldn't be completely torqued and the jeep needs to be on all fours, that's why most shackle and spring bolts have a mechanical locking nut
 
I did not tighten up anything till it was on the ground.I used three degree shims so I would not have a binding issue.I had to just walk away yesterday and not touch it today.I will jump in and see if I can figure out whats going on.

Just a thought if the driveshaft was binding could it cause the whole rear to bounce like that?I would not think so with shims but have been wrong before,I also called Rubicon Express there tech guys tried to be helpful but just told me to try everthing I already have.I was really hoping this had happened to someone else here.Ill let you guys know.
 
Also I have the Hd Offroad shackle relocator boxes with extended shackles sits at almost perfect 45 degree angle.have not tightened anything more than a turn past finger tight yet with ratchet.This is the full leaf pack RE1462 is the number
 
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Couple of stupid questions... 1 did you put the shims in correctly or backwards? What is your driveshaft angle with the shims in?
2- did you loosen or remove your driveshaft while doing this? Is it still tight
3- are your wheels/lugs on tight ? Are they properly seated?
 
Couple of stupid questions... 1 did you put the shims in correctly or backwards? What is your driveshaft angle with the shims in?
2- did you loosen or remove your driveshaft while doing this? Is it still tight
3- are your wheels/lugs on tight ? Are they properly seated?

1.Yes they are in correctly,that is a good thought though I have not checked the actual angle yet,I had the three degree shims laying around just wanted to get it together and see how everything worked and fine tune from there.
2.Did not disconnect the shaft for this as I did one side at a time.These are excellent questions,I think on the binding issue I will remove the rear shaft and drive it in four wheel and see if the problem goes away.Was not able to look at it from a standpoint where I could think it through cause I was freaking pissed!Thanks and keep the ideas coming:worship:
 
In answer to a question you posed: yes, you can install the leaves backwards. Large bushing should be towards the front of the vehicle. I'd imagine you could end up with an insane pinion angle if you installed them backwards. Take a few pics (front and rear leaf bolts, spring perches, and driveshaft angle with the diff visible) and share.
 
1.Yes they are in correctly,that is a good thought though I have not checked the actual angle yet,I had the three degree shims laying around just wanted to get it together and see how everything worked and fine tune from there.
2.Did not disconnect the shaft for this as I did one side at a time.These are excellent questions,I think on the binding issue I will remove the rear shaft and drive it in four wheel and see if the problem goes away.Was not able to look at it from a standpoint where I could think it through cause I was freaking pissed!Thanks and keep the ideas coming:worship:
3.yes they are tight and seated properly
 
In answer to a question you posed: yes, you can install the leaves backwards. Large bushing should be towards the front of the vehicle. I'd imagine you could end up with an insane pinion angle if you installed them backwards. Take a few pics (front and rear leaf bolts, spring perches, and driveshaft angle with the diff visible) and share.

They are not in backwards just grasping at straws last night. I will try to get some pics tomorrow,its now at my friends shop needed it out of my garage we are going to work on it tomorrow night hopefully we can figure it out.I will take pictures of it before and after Maybe it could help someone else in the future
 
yes, pics might help.
couple of other things if the rear axle removal doesn't point the way or you have 'gottagetdonitis'.

I dont know what else you did but are both of your spring perches sitting fully/properly centered? I seem to recall I had to enlarge the hole in the spring pad for the pin to fit through, did you do this?

does this 'bouncing' happen regardless if you're going straight or turning?

given that you said it happens at very low speeds, this should be easy to troubleshoot.

What do you mean in your original post by "..can easily bounce to rear with one hand"? Something in your rear is binding at one end of the driveshaft or the other, maybe the slip yoke, maybe the driveshaft, it's going to be pretty obvious when you look at it, you just installed a lift that dramatically changed the geometry of your entire suspension.....I foresee an SYE in your future!
 
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yes, pics might help.
couple of other things if the rear axle removal doesn't point the way or you have 'gottagetdonitis'.

I dont know what else you did but are both of your spring perches sitting fully/properly centered? I seem to recall I had to enlarge the hole in the spring pad for the pin to fit through, did you do this?

does this 'bouncing' happen regardless if you're going straight or turning?

given that you said it happens at very low speeds, this should be easy to troubleshoot.

What do you mean in your original post by "..can easily bounce to rear with one hand"? Something in your rear is binding at one end of the driveshaft or the other, maybe the slip yoke, maybe the driveshaft, it's going to be pretty obvious when you look at it, you just installed a lift that dramatically changed the geometry of your entire suspension.....I foresee an SYE in your future!

Yes they are sitting flush,I made sure they sat in the perches before I did anything else.I wondered about it sitting centered what would you measure to verify?
Yes it bounced no matter what only went a few feet to pull it on the trailer.
I can with one hand bounce the rear end at leat 6 inches with one hand!I can bench 300 but I should not be able to do that!
I have a SYE that goes in nex weekend.The overall lift is almost the same as it was before.AAL with 3 inch blocks (bought that way)and extended shackles blocks had a 2 degree taper this actually rode ok.Flexed like crap and looked like crap and stock springs were shot.I like to do one step at a time ie change springs make sure it works then move to sye etc.I hope its not the driveshaft or I am going to feel like an idiot.
I have lurked here for awhile this is my first Jeep,but I have been racing and building cars for a long time.Again thanks to all.
 
Re: RE 4.5 spring problem?(update)

Ok guys think I had multiple problems here.The first is Being new to jeeping I thought if I bought a 4.5 spring this is what I would get in lift,with my hd shackle relocators I would have 5 inches of lift right?Ha! no I have well over 6.I will never do another thing on this without doing research again:D.So now my rig is raked a bit but will give me an excuse to get some ACOS.The next problem was my new shocks were waaaayyyy to short.I think at ride height they were maxed and holding up the rear(allowing me to bounce with my hand)I got a 4 inch longer shck and built some BPE'S solved that problem.And finally got the sye in used front driveshaft everything seems to be good now,side note should have no problem clearing the 33's I have planned.My 31's just look silly now.

Sorry for being so long hopefully this might help someone else.If you are planning anything on a xj please read up if you are unfamiliar like me it will save you a lot of grief:banghead:Thanks to all who tried to help and happy wheeling.:cheers:
 
Do be aware that many springs will sag 1/2 - 1" in a fairly short time. So, your 6" may become 5" after a couple of thousand miles or a few trail rides.

David Bricker / SYR
 
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