Rear Springs in Relation to the Axle spring Pads

[broncosam]

Folks let me say up front that it's been a long time since I've done this type of suspension work. Maybe I've gotten ahead of myself in the re-assembly. The problem I've run into and need help with. I've changed out my rear springs, I have them in correctly with the military/double wrap to the front. I've got the passenger side of the axle bolted up loosely with the u-bolts and spring plate. Everything is fine on that side. On the driver side the center pin in the spring pack is not lining up at all to the hole in the spring pad on the axle. It's about 1.5 inches off center in two directions. The rear springs are already torqued to spec, should I have loose assembled everything before tightening it all up. I took a couple of pictures they are not the best but it will show what I'm up against. In the one picture the shiny spot you see is the hole in the axle spring pad.

 

[Rustytruck]

in your second picture is that a wedge on the bottom of the spring pack? is the front left or right in the picture? if that is a wedge and left is front that would be lowering the drive shaft angle which would be wrong way to go. Measure from spring eye to centering bolt on each side to verify the springs are right way around. measure eye on each spring to verify the springs are the same length. If I remember right the short measurement between eye to centering pin goes to the front. but don't take that as gospel as it has been a very long time for me.

 

[broncosam]

Yes those are 6 degree axle shims/wedges and they are installed the correct way, on the bottom of the spring with the thickest part of the wedge to the rear. The springs are the same length and like I said I have them installed correctly with the double/military wrap to the front. It's been a long time for me too, but this is the first time I've ever run into this. I've checked and double checked everything I can think of trying to figure this out. I'm wondering if I should've loose assembled everything before torqueing all the bolts for the rear springs. Everything is good or new, spring bushings, new spring shackles, all new hardware. This sure has me stumped. Thanks

 

[DirtDonk]

Loosen the springs in their frame mounts and slightly loosen the U-Bolts. Not too much of course because you don’t want the good pin to come out of the hole.
You should be able to manhandle the axle forward or backward while you manhandle the spring inward or outward to line up the hole and pin.
Most of the time if you’re lucky the spring is outward and all you have to do is push inward on the spring with your foot.

This slight misalignment is fairly common. Not only were the spring mounts and hangers not perfect from the factory, but add 50 years of used to them and the fact that even the spring perched on the axle might be slightly off too, and the likelihood that things are going to line up perfectly when you replace the springs with new ones is slim.

 

[DirtDonk]

It’s been a while for me too, but I have installed literally dozens of springs on different Broncos and not once did they line up perfectly without a little bit of Jimmying one way or the other.
However so far, luckily they have never taken more than a little bit of extra muscle to get them lined up.

 

[broncosam]

Loosen the springs in their frame mounts and slightly loosen the U-Bolts. Not too much of course because you don’t want the good pin to come out of the hole.
You should be able to manhandle the axle forward or backward while you manhandle the spring inward or outward to line up the hole and pin.
Most of the time if you’re lucky the spring is outward and all you have to do is push inward on the spring with your foot.

This slight misalignment is fairly common. Not only were the spring mounts and hangers not perfect from the factory, but add 50 years of used to them and the fact that even the spring perched on the axle might be slightly off too, and the likelihood that things are going to line up perfectly when you replace the springs with new ones is slim.

Thanks, I'll give that a try. That's the one thing that I've been thinking is the issue, loosening the rear springs to move things around a bit may be the cure. Will let you know if that works. Thanks

 

[DirtDonk]

Probably will help to loosen them more now that we use poly bushings in almost everything, vs when they had rubber.
It's not like the rubber was soft either, and the metal sleeves dug themselves into the metal, but the poly bushes have those shoulder/flanges that reduce sideways flex of the springs even more.
Hopefully this gives you enough movement to not have to go ask the Ahnold the neighbor to help you do some flexing!

Paul

 

[broncosam]

I got it done. Loosened everything up and put a ratchet strap from spring to spring and with the help of the jacks I was able to get everything back in place and torqued down properly. When I first put the springs on and tightened everything up I kept wondering if I should've left a bit loose till I get the axle in place and tightened up. Oh well, live and learn. I do appreciate the help and advice, thanks to all.

 

[DirtDonk]

Your thinking path was correct. Even to the point of waiting until the vehicles back on the ground to do the final torque.
That way gravity is not having to fight against the resistance of the bushings and sleeves.

Not too late though. Even if you have it on the ground simply loosen the fasteners back up (all six of them) and then jump up and down a couple of times on the bumper and torque them all back down.

 

[armynavy17]

Going along with DirtDonk above, it's probably better to not torque the leaves to the factory spec for the rubber bushings. There have been a couple of discussions here regarding poly vs rubber torque specs, but the consensus seems to be to torque the poly bushings less. Say 70 ft-lbs when the original spec it 75-105 for the rubber bushings.

I also had to use a ratchet strap and plenty of kicking to get the other side to line up, it seems to be par for the course. Rides great now though. Don't forget to re-torque in a few hundred miles. I got another 1/2 to 3/4 turn out of my u-bolts.

 

[broncosam]

Going along with DirtDonk above, it's probably better to not torque the leaves to the factory spec for the rubber bushings. There have been a couple of discussions here regarding poly vs rubber torque specs, but the consensus seems to be to torque the poly bushings less. Say 70 ft-lbs when the original spec it 75-105 for the rubber bushings.

I also had to use a ratchet strap and plenty of kicking to get the other side to line up, it seems to be par for the course. Rides great now though. Don't forget to re-torque in a few hundred miles. I got another 1/2 to 3/4 turn out of my u-bolts.

Damn, maybe I should've did more research on this before torqueing everything down. I torqued all the rear spring hardware, the shackles, and both ends of the springs, to factory specs. They all have poly bushings. So you're saying that those bolts don't require as much torque because of the poly bushings? That's the first I'd ever heard that and it would've saved from some muscle and joint soreness. So, should I loosen those bolts and re-torque them to just 70 ft-lbs?

 

[armynavy17]

I went with "probably better" above because it's still up in the air some. I guess the best answer is "it depends." Here's some additional reading so you can make the best decision for you.

Rear Spring Bolt Tightness

I just installed a 3.5" lift on my Bronco. How much should I tighten down my bolts, both on the front hanger and the two on the rear shackle? Also curious on the U-bolts too. I was wondering if the hanger bolts need to be a bit loose to let the suspension articulate.

classicbroncos.com

Poly Bushings Torque

While putting my '71 back together with Energy Suspension bushings I did a search on here to see what guys were torquing the radius arm to bracket nuts. I found a wide range of advice. In my own mind it made sense that these poly bushings wouldn't require as much as the OE rubber bushings...

classicbroncos.com

 

[DirtDonk]

Well it’s not necessarily a poly versus rubber material debate, so much as it is the type and length of inner sleeve that used.
You certainly can use factory torque if the sleeve bottoms out on the metal before the bushing crushes.
I’ve seen some pretty mangled poly bushings and deformed spring hangers because the sleeves were slightly short. The shoulder of the bushings locates the spring side to side and doesn’t need to be moshed out.

But there is nothing wrong with factory torque if the sleeve bottoms on the hanger.
If you must leave it slightly loose however, having good locking nuts to keep the torque consistent overtime is a must.

 

[DirtDonk]

Just to highlight some differences in design between the original rubber and replacement poly bushings, the original rubber bushings had extended sleeves with serrated edges that literally dug into the metal of the hangers when full torque was applied. The rubber did not contact the sides.
This rigidly located the inner sleeve to which the rubber was vulcanized, meaning that as the spring moved, pivoted or twisted, the rubber stretched back and forth but nothing else moved. Just rubber twisting itself to eventual destruction if/when it’s limits were exceeded.
With no shoulders to center the springs in the hangers you could eventually grab a spring and move it side to side by hand when the outer sleeve finally lost its tension against the spring eye.
This meant the spring moved around a lot in use and was generally not a good thing.

With poly the bushing can rotate around the sleeve and even to a certain extent twist inside the spring eye. So it’s still a good idea for the sleeve to be long enough to anchor things, but if it’s not everything is kind of free to move about the cabin. Eventually they wear out too, especially if rubbing on rough edges and surfaces.

So they’re kind of the same, but kind of different too.

All comes down to if the sleeves were correctly sized for the application.
Which means, like almost everything else we use on our Broncos, it’s up to us to watch how everything works together act accordingly.
So if when you tightened the bolts down everything bottomed on the sleeves without crushing the bushings, you’re good to go.

 

[Jdgephar]

Just re-torque those u-bolts after about 30 miles...and maybe again after another 30.

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[sprdv1]

Just re-torque those u-bolts after about 30 miles...and maybe again after another 30.

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not a bad idea....

 

[sprdv1]

Well it’s not necessarily a poly versus rubber material debate, so much as it is the type and length of inner sleeve that used.
You certainly can use factory torque if the sleeve bottoms out on the metal before the bushing crushes.

for sure bubba