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Delrin bushes - fitting concern

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Old 10-09-2009, 11:17 PM
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daveo90s4
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Default Delrin bushes - fitting concern

Just bought some Delrin bushes and am in the process of fitting them.

But:

The shaft on the delrin bushes is 20mm long.

The steering rack lugs the bushes go through is 18mm thick.

This means the delrin bush protrudes 2 mm through the rack lugs

This will give a lot of slop up and down in the rack - more than was there before and the very thing I'm trying to eliminate.

What should I do? Cut the bushes 2mm shorter? Pack with a large washer that goes over the outside of the delrin shaft? Other?

(Time difference between Oz and US means I can't get hold of Roger to ask him directly)

Any hekp much appreciated.

Help appreciated.

Dave

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Old 10-10-2009, 02:32 AM
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daveo90s4
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Put them in as received, torqued it all up to spec. and all seems very good. Turns in noticeably better than before.

So all's good - thanks Roger, very pleased.

Dave
Old 10-10-2009, 02:39 AM
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SeanR
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Sorry no one was here to give you direction, but you figured it out. There will be no issues with the way you did it. Have fun and go hit some curves.
Old 10-10-2009, 05:11 AM
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jon928se
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Same issue if you buy the Alu ones (I bought mine from Carl.) Looks wrong when you install them works fine when you tighten them up.

Edit. - I'm sure it turns in fine when you turn in - I'll confirm when the f£$%%$^&*(")&^%£$££%^& ing brakes work properly.
Old 10-10-2009, 02:13 PM
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Formula94lt1
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The delrin seems to expand slightly when torqued down making a pretty darn tight fit. Dont know how the aluminum ones hold it in place.
Old 10-10-2009, 08:04 PM
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Okv
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Originally Posted by Formula94lt1
The delrin seems to expand slightly when torqued down making a pretty darn tight fit. Dont know how the aluminum ones hold it in place.
They don't.
Looks good when you mount them, but after a while the rack is able to move up and down.

I cut mine down and used washers, then it should be clamped rigid to the mounting bracket.
Old 10-18-2009, 01:40 AM
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Formula94lt1
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I dunno, mine didn't just look good, one of the corners wasnt mounted flush and I tried to move it. Took a hell of an effort with a large pry bar and stayed where I pried it.

EDIT- ....or were you talking about the aluminum ones?
Old 10-18-2009, 01:43 AM
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Not understanding what the last two posts are talking about. The Alu ones are bad, or the delrin?
Old 10-18-2009, 01:42 PM
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We are in the process of modifying both the Aluminium and the Delrin bushes.
It is possible that the rack can move up and down after fitting the bushes. This is also the case with the factory bushings if the tops are not peened down after installation.
Thanks to design input from David - see first post - this potentail issue will be eliminated.
Roger
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Old 10-18-2009, 01:45 PM
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F451
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x2. I'm looking at replacing my bushing soon. Was going to go with the "aluminium" ones, but was concerned that the relatively soft aluminum would wear over time.

Delrin seems like it would allow a certain amount of minute movement without wearing, or with minimal wear given the slippery nature of delrin. So, questions:

Has anyone noticed any wear with the aluminum ones?

Has anyone noticed any wear with the delrin ones?
Old 10-18-2009, 01:46 PM
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F451
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Just saw your post Rog - very cool!

Any eta on the redesigned bushings?
Old 10-18-2009, 03:28 PM
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M. Requin
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Originally Posted by NeverLateInMyNineTwoEight
x2. I'm looking at replacing my bushing soon. Was going to go with the "aluminium" ones, but was concerned that the relatively soft aluminum would wear over time.

Delrin seems like it would allow a certain amount of minute movement without wearing, or with minimal wear given the slippery nature of delrin. So, questions:

Has anyone noticed any wear with the aluminum ones?

Has anyone noticed any wear with the delrin ones?
This concern about the softness of aluminum bushings is real, depending on the aluminum alloy chosen, but if it is something like 7075 or 2024 no worries, this stuff is hard - about the same as a good bronze bushing would be. I would be worrying more about a hard bushing distorting the holes in the rack over time. The rubber in the stock bushing can act as a shock absorber between the bolt shaft and body of the rack, and delrin could probably do the same, but could a solid metal bushing do this?
Old 10-18-2009, 03:55 PM
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Originally Posted by NeverLateInMyNineTwoEight

Has anyone noticed any wear with the delrin ones?
I just serviced my car this morning and while I had it on the lift I checked the bushing, no noticable movement or wear.
Still the most noticable improvement I have made to my car.
Old 10-18-2009, 04:05 PM
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Just curious, Delrin swells when it contacts and absorbs oil? How does this affect the bushing if you get oil on it, which is pretty probable under the engine.
Old 10-18-2009, 06:23 PM
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Are you sure you are refering to Delrin?
Delrin has a high resistance to fluids and oils.
Are you thinking of Nylatron maybe? Nylatron is similar to Delrin but has a high swell rate.


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