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Join Date: Sep 1999
Location: Santa Rosa, CA
Posts: 28
trailing arm bushing question

How does the trailing arm bushing work? I'm referring to the after market type. Does the shaft rotate relative to the inside surface of the bushing or does the outside surface of the bushing rotate relative to the inside of the trailing arm? Or does the bushing float relative to both? The modification consisting of the installation of a grease fitting to the trailing arm assumes that the bushing rotates wrt the trailing arm. If the bushing also rotates wrt the shaft then it doesn't help there. Since I'm going through the hassle of replacing them I'd like to understand how they are supposed to work and maybe I can do something that will last.

Aside from the squeeks that you get as the bushing lose their grease, the shaft is effectively frozen to the trailing arm. When the nut(s) on the shaft loosen the shaft is free to rotate which wears the hole on the suspension mounts. I haven't welded it up yet but it looks to be a hassle to get access to. If the motor was out it would help considerably.

I've been chipping away at the job of removing the shaft so I could replace the bushings. I'd hoped that I could do it without removing the trailing arm. I began with the nut and spacer trick to pull the shaft out. This worked pretty good but is slow, takes a toll on the shaft threads and destroys the nut. The shaft was almost out when it got really stuck. I tried using pipe clamps to coax it out to no avail. I finally removed the trailing arm, got a piece fo 1/2 inch water pipe into the trailing arm and over the end of the shaft and applied a BFH (that's a big French hammer or some such thing). That impulse did what the pressure of the pipe clamp could not and the shaft was free. Next time (the other side) I might be able to do it without removing the trailing arm. The aftermarket bushings pried out without any difficulty.
Old 12-02-2002, 10:37 AM
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Location: Long Beach CA
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The bushing stays with the arm, the shaft rotates from within. When you put a zirk in the arm to lube the bushing, you must drill throught the bushing itself and also slot it on the inside so that the grease can spread out. The zirk, after scerwed in, will keep the bushing from rotating. It shouldn't rotate on it's own, many have found it necessary to machine down the OD of the bushing beacase of such a tight fit. Another thing: I had more than one set to work with and I found that where one would not go in, the other would.

Just a thought, but if you could somehow manage to slot the inside in a spiral, the grease would have a better chance of reaching the opposite side of the zirk fitting. I would think also that any slotting should be kept shallow and to a minimum.
Old 12-02-2002, 11:04 AM
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Join Date: Mar 1999
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This is something that has bothered me for some time.
I have the aftermarket bushings also.
To make a long story short, I crawled under the car last night and checked out who was moving against what (the springs/shox are off).

On one side, the bushing (& shaft, or course) remained imobile and the arm rotated around the bushing......gud, thas what I want.
On the other side, the bushing and arm rotated around the shaft....not what I want......rats.

I hab a plan to fix......
I dont the flange of the bushing rotating against the console ear.
That ear is THE weak part of the rear suspension, as I see it.

(edit)
And, naturally, Milt wants the opposite..... .
This could get interesting.
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Last edited by J P Stein; 12-02-2002 at 11:10 AM..
Old 12-02-2002, 11:07 AM
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I, see your point JP (flat on my back under the car), but it still will rub on something else if not the ear. In other words, these things act as a thrust bushing as well. So they have to *bottom* on something. Anyway, if he wants the zirks, I don't see any choices on the matter unless he welds on a bung for the zirk to move it away from the bushing allowing it to move in the arm. In which case, machiniing will almost cetainly be necessary.
Old 12-02-2002, 12:17 PM
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Yup, I agree, it's gonna rub on something.
My preference would be the ends of the swingarm tube.
It's easier to replace bushings or swingarms than that ear.
To that end, I'm gonna polish up the inside and ends of the tube.
I'll take some pics of the process whenever it gets done......don't hold your breath.

As to lube, shallow grooves in the bushing OD, lube em' up and go for it.

As you are aware, the rubber bushings were never meant to be replaced. The internal flex of the rubber provided enuff rotation.
The hard bushings sux, but it's all we got without spending big bucks for needle bearings or other pricey rework.
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Old 12-02-2002, 12:50 PM
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