Suspension bushes

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tonym
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Suspension bushes

Post by tonym »

Took my PZ to have tracking checked and the tyre centre can’t undo any of the bushes. Also there is thumping noise when I’m driving and particularly on tick over. Could these be related or could the “thumping” be engine mounts, or anything I haven’t thought of 😇
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ChrisHolmes
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Re: Suspension bushes

Post by ChrisHolmes »

It is common for the adjusting bolts on the suspension to rust totally solid into the bushes. If you dose the top sides with penetrating oil such as Plus Gas over a period of several weeks then you may just get lucky and they free off but usually its a drilling and reciprocation saw job and can result in new lower arms being required and worst case a replacement subframe.
If they were just checking the tracking then they would normally only be adjusting the tie bars on the steering rack so is the caster and camber out of alignment.
Also check that they were using the RX-8 Sport settings as these are the correct ones for UK specification cars. I think the PZ settings are the sane as the S1 but if not I am sure someone will correct me soon.
Regarding the knocking that could be caused by wide variety of things and may just be the exhaust knocking but really you need someone experienced to hear the noise first hand.
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tonym
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Re: Suspension bushes

Post by tonym »

Thanks really helpful. The tracking place recommended a local garage that appears to specialise in bush freeing/renewal but they haven’t replied with a quote. Probably can’t get the parts. My local Mazda garage did a free Spring Health check ! didn’t find anything specific but at the time the heat shield was rattling away.
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Re: Suspension bushes

Post by ChrisHolmes »

This is a real case of if it "aint broke don't touch it!" so if the alignment is close and you are not getting abnormal tyre wear just leave it but do apply the penetrating fluid regularly as one day you may need to adjust or remove something.
Rotary History;

Sep 2005-Aug 2006 EO55 XOL VR 231 New
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warpc0il
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Re: Suspension bushes

Post by warpc0il »

ChrisHolmes wrote:
Wed Jul 13, 2022 12:41 pm
Also check that they were using the RX-8 Sport settings as these are the correct ones for UK specification cars. I think the PZ settings are the sane as the S1 but if not I am sure someone will correct me soon.
Yes, we were able to confirm that the "Sports Suspension" table settings apply to PZ's too, using the same "ride height" lookup.

However, as others have noted, the tolerance ranges in the tables still leave room for "season to taste" variations. :D

The tracking on any car can get affected by potholes or kerbing, though this is just the track rods.

If anything else is significantly "out" then either the suspension has been apart and not correctly reset, or something is broken.

For example, it wouldn't be the first time that a tyre place has chased around, trying to get the adjustments right, without noticing that both rear springs are broken #-o [-X
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tonym
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Re: Suspension bushes

Post by tonym »

Ok maybe not connected buttttttt. Had corrosion on the rear coils, MOT advisory. Had a mobile machanic remove coils, had them blasted and recoated and refitted. Could they have been refittted not quite right ?
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Re: Suspension bushes

Post by warpc0il »

The suspension arms, as they attach to subframe, must be left loose enough to rotate, until the weight of the car is compressing the spring, then they can be tightened, otherwise the rubber bush is held twisted and trying to lift the car itself.

If only one wheel is lifted at a time then the forces through the ARB distort the difference from one side to the other.

Even just lowering from the jack isn't enough to let the car settle, as the wheels have to roll at least a complete revolution before the suspension can sit correctly.

Removing the rear spring should only require the removal of the rear upper arm, so it's that pivot bolt that may need be loosened and re-tightened, on each side.
rear upper bolt.jpg
I've just been doing this on mine, as I fitted the PZ specification suspension on my '04 S1.
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ChrisHolmes (Thu Jul 14, 2022 11:45 pm)
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