Rx 300 Air? Suspension

Ken Sampson · October 3, 2015

Hi chaps, this is something I know nowt about, I've had my 300 for 10 years, (76,000 miles) before which it was a 'Showroom Demonstrator'. Driving it every day (almost) maybe I've acclimatised to it but it seems that the suspension has got a touch hard with an occasional clonk from the left rear somewhere not necessarily when going over bumps but sometimes on the flat.

Any Ideas? I'm not sure whether mine is an SE or SEL....

Jim

Geryatrix · October 3, 2015

You will need to look if the car is an SE or an SEL, as this will show if it has mechanical or air suspension. Both types after 10 years can show problems but completely different problems depending on the type.

PCM · October 3, 2015

Does it say, inside the glovebox?

PCM · October 3, 2015

Hi chaps, this is something I know nowt about, I've had my 300 for 10 years, (76,000 miles) before which it was a 'Showroom Demonstrator'. Driving it every day (almost) maybe I've acclimatised to it but it seems that the suspension has got a touch hard with an occasional clonk from the left rear somewhere not necessarily when going over bumps but sometimes on the flat.

Any Ideas? I'm not sure whether mine is an SE or SEL....

Jim

The 'clonk' ; When driving, braking, turning?

Ken Sampson · October 3, 2015

Does it say, inside the glovebox?

NO, inside the glovebox is a label referring to the air con filter.

Ken Sampson · October 3, 2015

Hi chaps, this is something I know nowt about, I've had my 300 for 10 years, (76,000 miles) before which it was a 'Showroom Demonstrator'. Driving it every day (almost) maybe I've acclimatised to it but it seems that the suspension has got a touch hard with an occasional clonk from the left rear somewhere not necessarily when going over bumps but sometimes on the flat.

Any Ideas? I'm not sure whether mine is an SE or SEL....

Jim

The 'clonk' ; When driving, braking, turning?

When driving, sometimes when turning.

Jim

ChrisKaye · October 3, 2015

Hi Jim,

Easy way to tell is if you have the "Hi" & "Lo" rocker switch between headlight washer and cigarette lighter socket by the gear stick.

My first thoughts with your clunk/noises would be worn bushes for the anti-roll bar...

Ken Sampson · October 3, 2015

Hi Jim,

Easy way to tell is if you have the "Hi" & "Lo" rocker switch between headlight washer and cigarette lighter socket by the gear stick.

My first thoughts with your clunk/noises would be worn bushes for the anti-roll bar...

Hi Chris, good to chat with you again, - I've just been out to the car to have a look, there is No "Hi" & "Lo" rocker switch - just a space between the headlamp washer switch and the cigi lighter... So what does this signify?

Jim

ColinBarber · October 3, 2015

Hi Chris, good to chat with you again, - I've just been out to the car to have a look, there is No "Hi" & "Lo" rocker switch - just a space between the headlamp washer switch and the cigi lighter... So what does this signify?

Jim

That you don't have air suspension and therefore you don't have the SE-L grade.

Ken Sampson · October 4, 2015

Thanks Colin, at least that's one thing less to have to worry about, maybe it's my imagination that the ride has become more solid?

Just to find the cause of that clunk now.

Jim

ColinBarber · October 4, 2015

Typically suspension gets softer with age as things wear but it is possible for a suspension strut to get stiffer and also be the cause of the clonk, although there are several others components that could be making the noise.

Ken Sampson · October 4, 2015

Thanks Colin, I'll have to have a check round to try to find the causes.

Jim

ChrisKaye · October 4, 2015

All my suspension (other than my refurbed rear strut and a replacement drop link/stabiliser bar on the nearside rear) is still original and on a '53 plate with 108500miles, you can definitely tell!

The corner I have just done on Friday is working so well, it has highlighted how bad the others are!

I think (other than replacing the nearside front air strut with another DIY refurb I have in the pipeline) I'll see it through winter and the road salt, then look at changing all front and most rear suspension bits that have worn after Christmas.

From looking at the rear recently, I will be changing the ARB bushes and clamps which aren't looking too hot - I'll probably remove the ARB itself, clean it up and Hammerite it before fitting the new bushes. The rear definitely looks easier to work on than the front as there is less components.

Interestingly, the rear drop links still looked in working order but unfortunately, I had to cut one off to replace my rear strut as the nut was fused to the thread and the hex bolt you have to use to hold the thread still whilst undoing the nut had been mangled in the past some how....

Do drop links usually only need changing once the have split and the captive grease has bled out, or do they deteriorate over time?

Ta,

Chris.

ColinBarber · October 5, 2015

The drop links can wear without splitting, not sure how common that is though.

Typically they are tested with the follow procedure, in addition to just checking if there is any play:

ChrisKaye · October 5, 2015

Colin, thank you!

That's very useful!

I think mine would have failed the resistance test (b) above, as you could spin the thread as much as you liked without it getting any stiffer to tun.

12years and a 100k and I'm not surprised, the RX is heavy after all!

ColinBarber · October 5, 2015

It always assumes me when people say their 10 year old vehicle with 100k miles on the clock drives like new. Clearly they never drove it new or they have long forgotten what it felt like.

ChrisKaye · October 5, 2015

That's true to some extent, you get used to the gradual deterioration over time which is very subtle but conversely, when you really know your car, you can tell when it's acting weird or a new noise occurs, or just simply switching fuel from normal to higher octane for example!

I have to say that I thought the Lex was a pretty smooth shifter before changing the automatic tranny fluid, but it's even slicker now!

I'm slowly ticking all my service items off the list and I'd say the least noticeable was the spark plug change recently...

Still have power steering to do and also transfer box and rear diff, so will be interested to see what noticeable effects this may bring (if any)!

PCM · October 22, 2015

Hi chaps, this is something I know nowt about, I've had my 300 for 10 years, (76,000 miles) before which it was a 'Showroom Demonstrator'. Driving it every day (almost) maybe I've acclimatised to it but it seems that the suspension has got a touch hard with an occasional clonk from the left rear somewhere not necessarily when going over bumps but sometimes on the flat.

Any Ideas? I'm not sure whether mine is an SE or SEL....

Jim

Did the 'clonk' get resolved now?