Urethane vs. Rubber vs. Delrin

sirhk100

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Anyone care to enlighten me with the pros and cons of each material as it pertains to leaf spring setups? I've heard lots of people talking about Delrin use in the leaf eyelets and on the shackle hanger pivit. I've heard that this may cause premeture wear on the leafs by forcing them to do the twisting motions from articulation. Where rubber and urethane allow the flex to happen in the ends instead of through the leaf itself. I've heard that rubber may allow too much movement but lasts for a long time where urethane may be perfect but needs replaced more often. This is all being based towards a prerunner that will not see the amount of prep that a race truck sees. What's your opinion on these three materials, pros and cons....

Khris

'92 Ford Exploder (AKA Dezert Limo cause it's loaded)
 

kjmiller1

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I just replaced my stock rubber bushings, because two of the original were completely shot and the springs were clunking because they were going back and forth. I went urethane because I THINK they are supposed to last longer than rubber, but they have a tendancy to squeek. Energy Suspension in San Clemente is the brand I ended up buying, but ford put an oddball set of springs on my truck so getting the right kit took a few tries, but they were quick to try again. Taking out the old bushings can be a bitch. Burning them works good if you can get the bushing to stay lit, I couldn't and ended up using a hole saw bit that worked good enough. By the way, I don't know what Delrin is, but I went urethane over rubber

93 f150
 

drtdevil93

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i dont recommend using delrin in the spring eyes. i have seen a tendency for the springs to break main leafs a lot. delrin is good for the shackle bushing, if no wishbone is being used.

rubber is good if you have limited suspension travel (12 or less). the way the rubber works, the eyebolt locks on to the inner steel sleeve, the spring eye locks the outer sleeve, and all suspension movement is from the rubber twisting. this is excellent for small amounts of travel, but will bind and wear quickly if used for long travel.

IMHO, urethane is the way to go in most cases. we use a slightly oversized inner sleeve, so you can torque the bolt all the way, and the bushing will still float. when installed properly, urethane doesnt squeak, will last a long time, and improve handling and feel.

we have a ton of bushings in stock, including stock replacement and urethane.


erik

<P ID="edit"><FONT SIZE=-1>Edited by drtdevil93 on 04/27/03 09:11 PM (server time).</FONT></P>
 

Jkrell

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I have heard similiar arguments for delrin....but I have a friend than runs delrin in all the pivots and hasn't had any leaf problems yet. For two years with my prerunner I ran urethane in the leafs and delrin in the upper shackle pivot. I offroaded some but not a ton and I broke the right rear urethane bushing a couple times (I think right rear from axel torque.....just a guess)....Since I started racing I have been running the hard rubber bushings. I changed them after about 160 miles of racing and a 100 or so prerun and test miles and they still looked pretty good....I have never had a problem with the rubber ones but last I heard deaver was recommending the urethane bushings.

I think I heard Kevin Davis runs rubber in his 7s truck becuase nothing else will survive....kritter would know better though.

Jon
 

sirhk100

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Erik,

When you say oversized inner sleeve... Do you mean a little longer so the bolt makes the shackle clamp down on it instead of the bushing? or are you meaning the ID is a little bigger then normal? I'm assuming you're meaning the first of what I'm asking...

Thanks for the info... I was thinking that Delrin in the shackle pivots and urethane in the leaf ends is probably the sweet setup but wasn't sure so I thought I would ask. Anyone else have info on the subject?

Khris

'92 Ford Exploder (AKA Dezert Limo cause it's loaded)
 

Jkrell

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no, feel free to keep that as a souvenir....I still can't believe you went another whole lap on that thing....I thought you were done for sure when you came flying off the course at me with your tire at about 50 degrees of negative camber. You doing a race this summer?
 

drtdevil93

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probably wont be together in time for the 400, i guess the lucerne race after the 400. it was funny, i go off course all of a sudden into a crowd. i was hoping i wouldnt hit anyone. when the dust clears, there is jon looking at me with this face that i could tell meant, dude you f'd your truck up. good times.

erik
 
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