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Greaseable Shackle Bolts

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Then he called me back, suggesting 9/16" that they have in stock and will fit the slots, but I reminded him the thread pitch is not correct for the captured nuts inside the 'frame' so that's no go.. too easy. Correct me if I'm wrong.

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I just checked - A 9/16-12 bolt will not thread into a M14-2.0 nut. Based on thread dimensions, I thought I might get a few threads of engagement, but instead it bound immediately.

With that said, its no problem to source M14-2.0 bolts of a variety of lengths and grades. The grade 10.9 M14-2.0 bolts for my shackle relocate were purchased from Fastenal.
 
I just checked - A 9/16-12 bolt will not thread into a M14-2.0 nut. Based on thread dimensions, I thought I might get a few threads of engagement, but instead it bound immediately.

With that said, its no problem to source M14-2.0 bolts of a variety of lengths and grades. The grade 10.9 M14-2.0 bolts for my shackle relocate were purchased from Fastenal.

Yup, exactly what Mike told me about 9/16" vs. M14. And he also sources bolts from Fastenal. Just that MORE will do the CNC, etc.
 
Got'em. M14 x 2.0 x 110mm. Waiting on the springs.
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Sent from my Pixel 4a using Tapatalk
 
Metric 10 is it? Or grade 8.


Sent from my Pixel 4a using Tapatalk
 
Metric 8.8

Class 8.8 (SAE psi I understand, Metric MPa not so much)

Head Marking: 8.8
Material: Medium carbon steel, quenched and tempered
Size Range: All Sizes below 16-mm
Proof Load (MPa): 580

Min. Yield Strength (MPa): 640

Min. Tensile Strength (MPa): 800

Size Range: 16-mm to 72-mm
Proof Load (MPa): 600

Min. Yield Strength (MPa): 660

Min. Tensile Strength (MPa): 830
 
Should be fine enough. I'm going to switch to urethane bushings for the rear of my leaf springs, so I'll be ordering a pair of those bolts.
 
Should be fine enough. I'm going to switch to urethane bushings for the rear of my leaf springs, so I'll be ordering a pair of those bolts.

Since the urethane bushings are two-piece, does that mean there's a gap in the center so the grease can get out to the bushing material itself?

I ask because when when I had my first OME lift installed ages ago, they installed that kind of bolt where the leaf packs went into the shackles, but OEM rubber bushings were used so I imagine any grease only ever saw the bolt and the sleeve it passes through. Maybe the shop used the greasable bolts because it was what they had handy, being a 4x4 shop?

Speaking of that sleeve, on OEM rubber bushings it seems like the center sleeve is just a flat piece of metal bent into a cylinder, but the bolts don't spin freely in them (like I'd expect to happen with the sleeves in the urethane bushings, since they look like they're cut from tube/pipe stock instead of formed). Are the bushings supposed to rotate freely on the bolts, or not? I've never really been sure.
 
Since the urethane bushings are two-piece, does that mean there's a gap in the center so the grease can get out to the bushing material itself?

I ask because when when I had my first OME lift installed ages ago, they installed that kind of bolt where the leaf packs went into the shackles, but OEM rubber bushings were used so I imagine any grease only ever saw the bolt and the sleeve it passes through. Maybe the shop used the greasable bolts because it was what they had handy, being a 4x4 shop?

Speaking of that sleeve, on OEM rubber bushings it seems like the center sleeve is just a flat piece of metal bent into a cylinder, but the bolts don't spin freely in them (like I'd expect to happen with the sleeves in the urethane bushings, since they look like they're cut from tube/pipe stock instead of formed). Are the bushings supposed to rotate freely on the bolts, or not? I've never really been sure.

On OEM bushings the center sleeve is not supposed to move, it's even bonded to it.
 
Since the urethane bushings are two-piece, does that mean there's a gap in the center so the grease can get out to the bushing material itself?

...

That's a good point. Any grease will find its way in the space between the bushing and leaf and between the bushing and the sleeve. Should be ok though.

The problem with the bonded rubber bushings is that they can't handle a lot of rotation. Mine appear to already be debonding. May also be due to the infamous RC quality. But either way, the urethane rotate more easily and may allow the rear suspension to be a bit more subtle.
 
On OEM bushings the center sleeve is not supposed to move, it's even bonded to it.

I think I think you've misunderstood the question I asked. Let me restate it to better explain where my head is at.

As the suspension compresses, the leaf spring flattens and "gets longer", causing the shackle to swing toward the rear bumper. This imparts some degree of rotational force onto the bushing and bolt in that eye of the spring. When the suspension droops, the spring "shortens" again and the shackle swings back toward the front of the vehicle

Unrelieved, this will cause the bushing to "wind up" like a torsion spring, which I assume is not an intended effect of cycling the suspension (in the same way that rotational stresses build up in a 231-equipped jeep operated in 4Hi on pavement where the wheels cannot slip).

Assuming that this "windup" effect is not part of the suspension design, there are only two ways that I can see to relieve it - either the bushing must rotate within the spring eye, or the bushing must rotate on the bolt.

Since the eyes in leaf packs do not normally come with grease fittings in them, I must therefore assume that the intention is for the bushing to be able to rotate freely on the bolt holding it to the shackle. The bolts we've been discussing in this thread support this conclusion, as they clearly are meant to supply lubrication to the space between the bolt and the inside of the sleeve.

With a urethane bushing, the sleeve looks (to my eye based on pictures) to have been made via extrusion - no seam, and perfectly cylindrical. Slipped onto a bolt in the hand, it seems like it should rotate quite freely. Not having handled any of this type, I don't know if the sleeves rotate in the urethane or not.

The sleeves in the OEM rubber bushings, based on the Clevites I used when I replaced my leaf packs several years ago, looked different. They appear to have been made by taking a flat piece of metal and bending it around a template - I could see where the two "sides" of that piece were brought together. When I slid a bolt into those bushings, I basically could not rotate the bushing at all on the bolt. This would explain why maxbraketorque reports delamination in his rubber bushings - the formed sleeves simply cannot rotate freely like the extruded ones found in urethane can.

My question was whether the binding of the bolt in the formed sleeves of OEM-style rubber bushings is supposed to occur, or if it's a sign of a manufacturing issue and they are supposed to spin freely as well.
 
Rubber bushings are bonded to the inner and outer sleeves, and therefore, the rubber is meant to twist / wind up like a torsion spring. It is bonded to prevent the leaf spring from sliding sideways on the sleeve or on the spring. Urethane bushings are fundamentally different in that the bushing spins on the sleeve. To prevent the spring from moving sideways, a lip is added to each side of the bushing that acts as meat between the spring and the shackle.
 
I can only "assume" but the FSM states to lower the weight onto the vehicle before tightening the bolts, and with really high torque values(they vary) there is not much chance they intended on the sleeve being able to rotate.
 
.. and Mike at MORE told me that he recommends only 35# torque on spring bolts SO they
WILL spin (talking TJ but shouldn't matter). I mentioned that OEM spec is 85# (or so) and he thought that would defeat the intended function.
 
.. and Mike at MORE told me that he recommends only 35# torque on spring bolts SO they
WILL spin (talking TJ but shouldn't matter). I mentioned that OEM spec is 85# (or so) and he thought that would defeat the intended function.

That's horrible advice. Most of the OEM bushings I seen have a serrated edge on the sleeves that would cut into the XJ uni-body in a heartbeat!
 
That's horrible advice. Most of the OEM bushings I seen have a serrated edge on the sleeves that would cut into the XJ uni-body in a heartbeat!

I always hesitate to stray from factory specs and this seemed to be an odd one.
 
Rubber bushings are bonded to the inner and outer sleeves, and therefore, the rubber is meant to twist / wind up like a torsion spring. It is bonded to prevent the leaf spring from sliding sideways on the sleeve or on the spring. Urethane bushings are fundamentally different in that the bushing spins on the sleeve. To prevent the spring from moving sideways, a lip is added to each side of the bushing that acts as meat between the spring and the shackle.

thanks for clarifying. I learned something today.

Tha
 
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