27 replies to this topic

[WindyStig]

Hi

 

I have a problem that i think must be related to something getting warm and expanding. After i have driven for about 20 miles i get a knocking noise from the rear suspension. Once the car is left for a bit it goes away.

 

I did a search on the forum and someone posted a similar issue in 2003 but no one had any ideas then.

 

It's not the end of the world but would be nice if i could get rid of it and there is the possibility the knock is doing other damage that will pop up in future.

 

Any ideas out there?

 

Dan

[techieboy]

Rear toe link(s).

[fezzasus]

http://www.elise-sho...0-p-502166.html

 

[WindyStig]

Is it a 'must fix' or just irritating that can be ignored for now?

 

[fezzasus]

 

This happened when one failed.

[WindyStig]

Ah! best get on to fixing that then! Thanks for the help.

 

Dan

[techieboy]

Well, you might want to check it is one of the toe link joints first, but they are the most likely source, if it really is from the rear and happens when the car is warmed up.

[fezzasus]

No problem,

 

basically it's a common problem but not documented as a serviceable part. The problem arises because the toe links are mounted too close to the exhaust, with time the exhaust burns off the grease and they start to wear rapidly. Eventually they snap, the above photo was a roundabout taken at about 30 mph when they went, so it's not under high load occasions either.

 

You can either replace them at around £70 each side from Autovaux with original parts, or pay £210 for an uprated pair from elise shop as I linked to, as the originals are in short supply I opted for the latter. They are a better joint design which protects against normal mode of failure.

[WindyStig]

No worries. Will get it checked and if they are a little worn will go for the elise set. Thanks for the advice guys.

 

Dan

[ghand]

I may be wrong but I suspect they snap at the thread due to abuse with sticky tyres and track stuff and not the actual joint which will just knock as it wears. Maybe someone knows which bit actually snaps .Mine knocked for a long time when very hot but was 10 year old with 70k on it. If a standard £25 joint lasts 10 years is it worth uprating for road use?

[2deano5]

I'm sure your going to check first but it might not be the toe links,

 

Mine started knocking when hot and it turned out to be the lower wishbone front bearing that had gone.

My advice is get someone who knows how to check first before buying what might not fix the problem. Thou if it is the wishbone I'd replace the toe links as well 

 

Good luck

[G-Bob]

Likely to be the passenger side one.

[fezzasus]

I may be wrong but I suspect they snap at the thread due to abuse with sticky tyres and track stuff and not the actual joint which will just knock as it wears. Maybe someone knows which bit actually snaps .Mine knocked for a long time when very hot but was 10 year old with 70k on it. If a standard £25 joint lasts 10 years is it worth uprating for road use?

 

As soon as there's enough play for fretting to occur then the failure could occur under any condition.

[slindborg]

Just as likely to be the drivers side one too. I followed the pax side advice and it turned out that one was fine and it was the other side a fault.

[WindyStig]

got it booked in to be looked at tomorrow. Will make sure that is the problem before i splash out on parts.

 

Appreciate the advice everyone. It's embarrassing how much i don't know about this stuff

 

Dan

[ghand]

I may be wrong but I suspect they snap at the thread due to abuse with sticky tyres and track stuff and not the actual joint which will just knock as it wears. Maybe someone knows which bit actually snaps .Mine knocked for a long time when very hot but was 10 year old with 70k on it. If a standard £25 joint lasts 10 years is it worth uprating for road use?

  As soon as there's enough play for fretting to occur then the failure could occur under any condition.

No your fretting to much they snap through impact damage, pot holes at speed and the like or abuse on track over time even over tightening of the nut which may be common.The picture I looked at the top thread had snapped under the nut a dry joint with slight play should not make the shaft snap. I have seen these type of joints flopping about like a turd in a p*ss pot on old cars without failure.

[WindyStig]

No your fretting to much they snap through impact damage, pot holes at speed and the like or abuse on track over time even over tightening of the nut which may be common.The picture I looked at the top thread had snapped under the nut a dry joint with slight play should not make the shaft snap. I have seen these type of joints flopping about like a turd in a p*ss pot on old cars without failure.

 

 

Impact damage would make sense. Where i live is pothole capital of the world. It will either be something in the rear suspension or my spine that is making the knocking noise!

 

Dan  

[Guesty88]

Out of interest, how easy is this to self diagnose and replace if needs be? Is it simply a case of jacking the car up, removing the wheel and inspecting for play and/or visual wear in the suspension?

[fezzasus]

You don't even need to remove the wheel. I would suggest taking the undertray off to do it though.

 

1. Undertray off

2. Jack up

3. Pull/shake hard toe link on the hub side

4. Pull/shake hard toe link on chassis side.

 

If you feel any play, replace.

[fezzasus]

You will need to find a way to measure and reset the rear toe if you replace them, or get it booked in for a geo afterwards. I used fishing line on axle stands and measurements from the centre of the hubs relative to the ouside of the wheel to set the toe to previous measurements