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Poly suspension bushings...yes or no?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by chev4life, Jun 10, 2003.

  1. chev4life

    chev4life 1/2 ton status

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    I currently have a 4" superlift and am finally getting around replacing the remaining stock bushings. I have looked at the ORD front shackles and the greasable rear end kit...how good is it? I am mainly on the street, but I try to make to the trails at least 4-5 times in the summer and to the mud as much as I can in the winter. Will poly restrict my articulation too much or will it be just fine? Anyone who has used these and can give me some info would be great.
     
  2. Triaged

    Triaged 1/2 ton status

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    I bought the greasable bolt/poly set for the rear. I wouldn't do it again. The bushings are a pain to get out!!! The greasable bolts were grade 5 corse thread with a hole drilled in them and the stock bolts were grade 8, with just a bit of threads on them so the shank of the bolt was the one riding on the spring hanger, and they didn't have any holes drilled in them. Your truck will also ride nicer with the rubber bushings and flex better. I see no reason to spend the $$$.
     
  3. gravdigr

    gravdigr 1/2 ton status

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    from the ord website
    [ QUOTE ]
    This shackle kit increases the bolt size from 7/16" to1/2" and increases the sideplate thickness to 3/8" for improved durability. The bolts are Grade 8 for maximum strength

    [/ QUOTE ]

    I pulled apart poly bushings with my bare hands, you gotta keep em greased, as opposed to the rubber bushings I replaced...I had to burn em out with a torch. I can't comment on suspension flex as my rig isn't on the trail yet (still being built). You can also post any questions you have about ORD parts in the ORD forum here and stephen will answer them the best he can.
     
  4. chev4life

    chev4life 1/2 ton status

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    Thanks for the info guys...I was leaning towards hunting down some OEM rubber for the shackles but wanted to get a few opinions first.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    If it helps any, I posted some part numbers for (suspected) suspension bushings, but the manual isn't clear.

    Still haven't seen that anyone has found aftermarket rubber bushings yet. The OEM stuff was kinda pricey as I recall, $10-15 or so per hole.
     
  6. pilgrim

    pilgrim 1/2 ton status

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    I say yes, dude.. buy those poly bushings. i just put in full set from ORD and they were very good quality... 1/2" grade 8 bolts and the front shackle's are 3/8 thick /forums/images/graemlins/thumb.gif.

    getting out the 20 year old /forums/images/graemlins/shocked.gif rubber bushings was the hard part. once thats done its cake. i see no reason to put back in the rubber ones... plus if you go to the dealer to get them i think you'll be paying way more than you would for ORD's quality poly one's....
     
  7. k20

    k20 3/4 ton status

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    [ QUOTE ]
    Your truck will also ride nicer with the rubber bushings and flex better. I see no reason to spend the $$$.

    [/ QUOTE ]
    I can see the ride nicer part, but i dont really see the flex better. If ya think about it, rubber is alot stickier than poly, so its gonna grip that center bolt, its gonna grab the spring eye, and its gonna sorta twist. Whereas the non-tacky poly is gonna more or less rotate in the spring eye. Am I way off on this?
     
  8. Triaged

    Triaged 1/2 ton status

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    I forgot about the rubber being bonded to the inner and outer sleeve...

    I would like to see some bushings that were made to fit inside the outer steel shell that way all you would have to do is remove the inner sleeve and rubber (the easy part). The shackle bolts for the front are grade 8 but the rear ones are made grade 5. The front shackles are not so much of an upgrade as they use the same size bolts and length shackle (just a bit thicker) as a 87-91 k5. If I had it all apart and the rubber bushings were shot (mine were not and my truck is a 71 that none of the other rubber has survived on!) I would replace them with poly. I would also make my own sleeve (thinner so I could use a bigger bolt), use an AN bolt and drill and tap the SPRING for a grease zerk to make it greasable. I really don't like the idea of drilled bolts but it was the easy way out.
     
  9. gravdigr

    gravdigr 1/2 ton status

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    greasing the spring will get the surface between the poly bushing and the spring greased, but it dies nothing between the bushing, sleeve, and bolt. Greasing from the inside out pushes grease into all these areas.

    [ QUOTE ]
    The shackle bolts for the front are grade 8 but the rear ones are made grade 5.

    [/ QUOTE ]

    he wasn't asking about the rear shackles or bolts. In any case also from the ORD site

    [ QUOTE ]
    Greasable Rear Suspension Bushings


    Drilled and crossdrilled grade 8 bolts and sleeves


    [/ QUOTE ]

    Research research research...Also I'm curious on any returns ORD has had from broken bolts...They did have a problem with the bushings splitting but that design flaw got fixed and customers got new bushings.
     
  10. Triaged

    Triaged 1/2 ton status

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    [ QUOTE ]
    he wasn't asking about the rear shackles or bolts

    [/ QUOTE ]
    This is from his first post:
    [ QUOTE ]
    I currently have a 4" superlift and am finally getting around replacing the remaining stock bushings. I have looked at the ORD front shackles and the greasable rear end kit...

    [/ QUOTE ]

    He already has poly front bushings except for the top of the shackle. Doesn't say what in the rear... I would assume blocks but if he does have leaves some of them come with stock type rubber bushings in them (a pain if you want poly).

    [ QUOTE ]
    greasing the spring will get the surface between the poly bushing and the spring greased, but it dies nothing between the bushing, sleeve, and bolt. Greasing from the inside out pushes grease into all these areas.

    [/ QUOTE ]

    If you left the stock outter sleeve in from a rubber bushing(or sealed where the eye loops around) it would get into the center of the bushing/sleeve just fine. You don't need grease in between the sleeve and bolt as they should have no motion at all.

    [ QUOTE ]
    Greasable Rear Suspension Bushings
    Drilled and crossdrilled grade 8 bolts and sleeves

    [/ QUOTE ]
    I thought they would be grade 8 and fine thread...they were grade 5 corse thread when I got them. I thought the point of upgrades was to upgrade /forums/images/graemlins/confused.gif not downgrade. Strength issuse asside you cannot torque a corse grade 5 bolt anywhere near as tight as you can a fine grade 8. This will cause the sleeve to be held looser than factory and increases the chance of slipping between the sleeve and spring hanger or shackle. Added to that is the fact that the threads are the part that will contact the hanger if/when it moves (un-like the stock bolt!). This will chew up and ovalize the spring hanger if left unchecked. Doesn't sound like fun to me.

    [ QUOTE ]
    Research research research

    [/ QUOTE ]
    /forums/images/graemlins/rolleyes.gif

    [ QUOTE ]
    Also I'm curious on any returns ORD has had from broken bolts

    [/ QUOTE ]
    One of the SoCalBigdawgs has broken SEVERAL front bolts (at least one set being ORD greasable). He has now IIRC gone to bigger non-greasable bolts with no sleeve and a locknut.
     
  11. gravdigr

    gravdigr 1/2 ton status

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    OK somehow I missed him mentioning replacing the bushings in the rear, my bad.

    [ QUOTE ]
    If you left the stock outter sleeve in from a rubber bushing(or sealed where the eye loops around) it would get into the center of the bushing/sleeve just fine. You don't need grease in between the sleeve and bolt as they should have no motion at all.


    [/ QUOTE ]

    yep, no motion at all. So little in fact that when replacing my rear springs I had to burn them off because the bolt was galded to the sleeve.

    [ QUOTE ]
    I thought they would be grade 8 and fine thread...they were grade 5 corse thread when I got them.

    [/ QUOTE ]
    you should have contacted them then because it clearly states here http://www.offroaddesign.com/catalog/greasebushings.htm th rear bolts are grade 8, and the stock ones are coarse thread. Just how much torque do you need?
     
  12. chev4life

    chev4life 1/2 ton status

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    Ok...a little more info...I have front and rear springs (only block is my zero-rate in the back) The superlift came with eye bushings, but the shackle bushings are shot. I also read the grade 8 thing...they better be. I was looking at there greasable rear and front with the new front shackle. If I got the whole thing it would run me around $200 which is why I am looking at other options. When I did my lift I pulled all the bushings out...they all came out fine...but I didnt even think of replacing them cause I didnt have new ones in front of me and I just wanted to get it done, now I get to go in and do it again. I am going to call ORD and make sure that all the bolts in their kits are grade 8 other wise I will find something else. Anyone break the front shackles of theirs?
     
  13. rampage

    rampage 1/2 ton status

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    [ QUOTE ]
    you should have contacted them then because it clearly states here http://www.offroaddesign.com/catalog/greasebushings.htm th rear bolts are grade 8

    [/ QUOTE ]
    Clearly you haven't been around CK5 too long. ORD use to use grade 5 bolts because they were easier to drill through the center. Stephen changed the design after being questioned on the use of grade 5 instead of grade 8. I don't remember if they use to be course grade also, he may have changed that too.

    Do your research here.
     
  14. Triaged

    Triaged 1/2 ton status

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    See this thread.

    My bolts had to be cut out as well (or I would have reused them!). They were rusted to the inside of the sleeve. Mine had never moved. So when you ask how much torque do you need I guess the answer is the torque for a fine thread grade 8 and not a corse thread grade 8

    Stephen and I don't see eye to eye on this either.
     
  15. Triaged

    Triaged 1/2 ton status

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    [ QUOTE ]
    Anyone break the front shackles of theirs?

    [/ QUOTE ]

    I don't think anyone ever has or ever will.

    I bought my bushings about a year and a half ago. If they have changed sence then I have no idea.
     
  16. rampage

    rampage 1/2 ton status

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    Damn! You found that thread before me /forums/images/graemlins/angryfire.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif
     
  17. gravdigr

    gravdigr 1/2 ton status

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    [ QUOTE ]
    [ QUOTE ]
    Anyone break the front shackles of theirs?

    [/ QUOTE ]

    I don't think anyone ever has or ever will.

    I bought my bushings about a year and a half ago. If they have changed sence then I have no idea.

    [/ QUOTE ]

    I have a set of factory front shackles that look like the hulk used em for toothpicks /forums/images/graemlins/cool.gif

    If money is an issue and you just want something to throw in for a while to test why not just get a set of energy suspension bushings? I got a set to put on my rig temporarily until I got it finished, was $9 a side for the shackle end.
     
  18. dyeager535

    dyeager535 1 ton status Premium Member

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    [ QUOTE ]
    I can see the ride nicer part, but i dont really see the flex better. If ya think about it, rubber is alot stickier than poly, so its gonna grip that center bolt, its gonna grab the spring eye, and its gonna sorta twist.

    [/ QUOTE ]

    The issue is not during normal flat ground suspension movement. When you raise one tire higher than the other (on the same axle) something has to give.

    Imagine how the axles are held in place with the springs: rubber bushing pressed into the spring, with a metal sleeve bonded to the bushing. Metal bolt passing through the metal sleeve holding the spring to the shackle. During normal suspension travel, as long as that bolt can rotate inside the sleeve, no problem. (and on trucks that are driven, I've never seen the bolt "locked" in place. Hard to remove yes, hard to rotate no) But when you raise one tire higher on one side than the other on the same axle, something has to give. Rubber will allow that spring to actually twist somewhat, which allows the bolt to continue to rotate "normally".

    With poly, you are limiting the amount of spring angle that bolt can take before you put a *lot* of force on it and the corresponding sleeve. No matter if its greasable or not, that has nothing to do with the fact that if the bushing material won't deflect, you've either stopped the flex, or its transmitted to the next weakest spot. (rivets, shackles, etc) That's my suspicion as to why the early poly ones fell apart.

    Even 4 link rear suspensions are this way...the angle and load is never "perfect", and ends up binding. Plenty of people running poly in the rears have noticed that the bushings "stick" in place and the ride height varies because of that.
     

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