Help! Odd handling characteristics on 924S

[chris71]

Hi,

Just bought a 924S and discovered a number of alarming traits that weren't obvious on the suburban test drive!!

Basically, I think there is a lot of play in the front end......

The car feels 'floaty' mid corner even when not cornering too hard, but the ride doesn't feel underdamped if you do a slalom down the road. The ride seems to be rather harsh ("crashy") given its not set up that stiff. The steering feels like its doing its own thing to a certain extent and the car seems to wander under higher lateral loads, but again nothing dramatic enough to break the tyres adhesion (possibly warn steering arm ball joints??)

....when you do speed up you get immense understeer, although this may be due to the state of the front tyres.

Its difficult to describe, but it just generally feels the wheels are moving around more than they should - something(s) is flexing. Does that make any sense??

I'm thinking about - suspension bushes, steering rod ends, steering rack/column, springs/dampers. Etc.

Also, can anyone recommend what manual to get for a 1988 924S (Uk spec). There doesn't seem to be one as such so, 924 manual for suspension stuff and 944 one for the engine??

Any other help very much appreciated, I know far less about these cars than I should!!

Chris.

[nynor]

have you checked the really basic stuff, like tire pressure? my 83 did weird stuff at freeway speed. turned out that all the tires had low pressure and it wasn't obvious from their appearance.

[924Sman]

Chris the best solution now is have a good inspection of the obvious parts for wear. Look at the tie rod end rubber seals. Raise the car and check the wheels for play in the bearings. Look at the strut bearings located under the bonnet. Ball joints and the bushings to the A arm. Front sway bar bushing on the PS tank side is usually soaked and deteriorated.
Alignment may be off.
Start with that stuff and see how things go before considering the steering rack.
As far as a manual goes a factory one is my only suggestion but the Porsche Technical and Dimensions manual is a good reference book for specs ROW, US and Euro. Book number is...WKD 423 320 Models Dimensions Tolerances for 924S/944.........around 30 US dollars.

GL!

Dal

[924RACR]

The state of the front tyres - what state, exactly, do you mean?? These cars can be very sensitive to tire selection and condition. In addition to the afore-mentioned checks, if you have it in your budget now or soon to get new tyres - you may be well off considering replacing them sooner than later.

[Nigel Haslock]

I'm working with th 944 Haynes Manual plus Clarks Garage and other online sources of info.

Nigel

[CJFusco]

chris - definitely play with the tire pressures. I thought something was wrong with my suspension because the front felt really nervous and felt like it was understeering though most corners until the point of oversteer... in other words, i know these cars are supposed to feel "neutral", and mine didn't.

My tire pressures were the recommended PSI for stock factory tires (29 front, 36 rear, I believe). But here's the thing: my tires are bigger than stock (225 vs 205) and my suspension is far from stock. I remember reading somewhere about a way to balance out understeer is to increase the front tire PSI, decrease the rear, or both. I increased the front PSI to 33 or so, and the weird handling traits I noticed before were much better. At 34.5, they were gone.

[SoCal Driver]

Some one stole your sway bars.

[CJFusco]

Hah well I suppose that could be it too.

[Kevin0323]

Does the tread on the rear tires go out faster then the front because it's rear wheel drive or do the front tires wear out faster than the back because of all the steering?

[nynor]

my experience is that the rear wheels wear faster.

[Tervuren]

I'd say that would have to do with setup and drivng.

Do you ever hear/feel a slight "chunk" up front? If so, probably the front wheel bearings are loose, allowing the tire to float a bit, throwing the cambers off and reducing grip.

[macreel]

Chris71... also, be sure the sway bar bushing struts aren't broken.

G'luck.

[chris71]

Thanks guys.

I've only just got the car and when I picked it up I was told the tyres had all been set to the "correct" pressures - 29 and 36 psi sounds familiar. Will double check - can anyone suggest anything different?

The rears are pretty good, but the front tyres are heavily warn. I'd be surprised if even in there current condition they're bad enough to produce the level of understeer I'm getting - its commical. Although a good prod of the throttle can give you snap oversteer as an alternative!

It feels like somethings deflecting though (hence the comment about the bushes) - if it was just the tyres I'd expect them to be consistently poor, instead it can 'squirm' mid corner without any change of conditions. This feeling is carried through to the steering, which seems to lack feedback compared to what I'd expect from a well set up RWD car and seems imprecise - has anyone heard of the steering arm joints failing?

My current plan (because its my only transport and I don't have much cash at the moment is....) new set of front tyres and tracking adjustment, then replace as many bushes as I can get to easily(!) and then maybe a set of new springs and dampers along with the rest of the bushes when my credit card has recovered!!

Thanks very much for your help

[924Sman]

Buy bushings instead of springs. Doubt the springs need changed, dampers yes but not the springs so instead of putting cash into the springs buy all the bushings.
New tires are of no help untill the suspension is in spec or the new ones will look like the old in no time. Swap the rears to the front get the rest in spec and see how it tracks, adjust then get new tires.

Dal

[chris71]

Originally posted by 924Sman
Buy bushings instead of springs. Doubt the springs need changed, dampers yes but not the springs so instead of putting cash into the springs buy all the bushings.
New tires are of no help untill the suspension is in spec or the new ones will look like the old in no time. Swap the rears to the front get the rest in spec and see how it tracks, adjust then get new tires.

Dal

I would do, but its my only car and at the moment its borderline dangerous. I want to get the new fronts first so I can stop even if its still far from ideal. I'd get the tracking checked at the same time and put right if necesary.

As soon as possible after that I'd get the bushes changed. Is that a difficult job? I gather you need a press to push the new ones in? Also, like I said, its my only transport, so really need to be able to do it over a weekend (before driving to work on Monday morning!!)

[924Sman]

I suggested the swap of the rear to the front for better tread to rule out tires as the main issue. You can see with tread how it handles first then move forward. No press is needed on the front bushings just the rear trailing arm bushings need a press. Ball joints need the rivets ground down to replace the joints using Grade 8 nut and bolt to mount the ball joints to the A arm. Ball joints on this model are riveted on vs late style.

Not difficult to replace any of the front suspension components.

2...lower sway bar bushings

2....upper sway bar bushings

2 rear A arm bushing blocks, mount to body

4 bushings on the A arms...2 on each arm, these will be the only real hard ones to remove but not a deal killer.

Strut bearings are easy as well but helps to have a pneumatic gun to spin the nut off while holding the strut shaft.

Dal

[chris71]

Cool, thanks Dal.

How exactly do you get the bushes in?

BTW for future reference - what spring/damper rates do you recommend for fast road use? (baring in mind these are bumpy english roads - maybe want the car a little stiffer than stock, but not too much more!)

[924Sman]

200-250#

The rear bushing slides on the A arm post. The others depend on the type of bushing used ie stock or race upgrade. But they are lightly pressed in but no press is needed.

[chris71]

Sounds good - any special tools in order to get to them?

[924Sman]

Springs do but the rest is general tools. Block of wood and or a hard rubber mallet.