Trying to understand 987 front suspension

[zcacogp]

Hi, 

 

Long story cut short: I've recently bought a 987 Cayman (Boxster with a roof!) and am trying to better understand the front suspension as it's started making some clonks recently. 

 

It seems that everyone buys Coffin Arms like they are going out of fashion. I can see on a diagram what these do but why are the 'tuning forks' not changed more often? (Or are they?) I'd have thought that they wear at the same rate as the coffin arms but could be wrong. 

 

People also refer to 'drop links'. Are these the ARB links?

 

I am also very confused about what coffin arms to buy as it seems that there are numerous versions out there and everyone has a different idea about what fits which model of car. I think I need part number 997 341 053 04. I am heartened by the fact that Max at Frazerpart lists these on his website as I've used Max for parts for other Porsches before and know he's good: 

 

https://www.frazerpart.com/acatalog/987_Boxster_Cayman_997_Carrera_Front___Rear_Control_Arm.html#SID=136

 

Are there other suppliers who I should be looking at? Everyone seems to say that 'Meyle' are the brand to go for. Is it worth trying other brands or are they just a waste of money? (I notice that there is no brand mentioned on the Frazerpart website). 

 

And, for my particular situation with a car that is new to me but has 970000 miles on it and no record of suspension work, what would you do? Coffin arms or more? FWIW I had the front subframe almost entirely off last week to change the coolant hoses (this car has really kicked my ass since I bought it) so there is a faint chance that there is something loose there but I slightly doubt it. 

 

All advice welcomed. Thanks. 

[zcacogp]

Replying to my own topic ... has anyone heard of 'Spyder Performance'? They have two coffin arms for £175, which is a good price. Brand not mentioned though. 

 

https://www.ebay.co.uk/itm/2-X-PORSCHE-987-CAYMAN-BOXSTER-FRONT-LOWER-COFFIN-CONTROL-ARM-99734105304/333270855153?epid=1568106423&hash=item4d987dadf1:g:DqoAAOSwECNdMOp3

[edc]

Spyder aka Eporsch. They are made by the same people that do the Meyle ones. 

[red rocket]

48 minutes ago, zcacogp said:

Hi, 

 

Long story cut short: I've recently bought a 987 Cayman (Boxster with a roof!) and am trying to better understand the front suspension as it's started making some clonks recently. 

 

It seems that everyone buys Coffin Arms like they are going out of fashion. I can see on a diagram what these do but why are the 'tuning forks' not changed more often? (Or are they?) I'd have thought that they wear at the same rate as the coffin arms but could be wrong. 

 

People also refer to 'drop links'. Are these the ARB links?

 

I am also very confused about what coffin arms to buy as it seems that there are numerous versions out there and everyone has a different idea about what fits which model of car. I think I need part number 997 341 053 04. I am heartened by the fact that Max at Frazerpart lists these on his website as I've used Max for parts for other Porsches before and know he's good: 

 

https://www.frazerpart.com/acatalog/987_Boxster_Cayman_997_Carrera_Front___Rear_Control_Arm.html#SID=136

 

Are there other suppliers who I should be looking at? Everyone seems to say that 'Meyle' are the brand to go for. Is it worth trying other brands or are they just a waste of money? (I notice that there is no brand mentioned on the Frazerpart website). 

 

And, for my particular situation with a car that is new to me but has 970000 miles on it and no record of suspension work, what would you do? Coffin arms or more? FWIW I had the front subframe almost entirely off last week to change the coolant hoses (this car has really kicked my ass since I bought it) so there is a faint chance that there is something loose there but I slightly doubt it. 

 

All advice welcomed. Thanks. 

I will be watching this with interest as I am also planning some suspension refreshments. Initially planning only new ARB bushes then step by step from there, but probably also the ARB drop links.

Can't answer your first question but believe correct part is 997 341 053 03 which I have taken from my copy of the Cayman PET. I suspect the 04 version is same - suggest you Google Cayman PET to find your own copy which has all the parts diagrams (I may have found mine on here or could be the PCGB forum or Caymanoc). Confusingly what you, I think, call a coffin arm  is called a wishbone by Porsche. And tuning forks are called control arms.All good fun!

I checked prices recently and found Meyle coffin arms for £113.70 from Frazer.

Edit:If you click on details within your link you'll see they are Meyle and i see various part no's listed.

[edc]

Coffin arm is just a layman's colloquial term because this arm is shaped like a coffin. You can call it a control arm, lower control arm, wishbone, all of which would be correct. Tuning fork is also so called because of the shape and if you tap it right it can sound like a you know what. 

[red rocket]

@zcacogp just remembered where to get the PET https://jasmine-porschalink.co.uk/porsche-pet-diagrams/

[Tony Daniel]

Front 'coffin arms' on are 987 are different to the rear and different to a 986. I have used OEM and no OEM arms and not found any difference although speaking to Jasmine today they say they have issues with the none OEM ones been a millimeter longer which can throw out alignment. 

I have just replaced the front and rear 'tuning forks' and rear toe links all in one hit as a lot of the cost is in your alignment afterwards. I'm using Spyder performance front arms for the first time so we will see how they last

You can replace the rubber bushes in the coffin arms, but not the ball joint. So I wouldn't recommend doing this with old arms

[zcacogp]

Chaps, 

 

Thanks for your comments. One by one; 

 

- EDC (the same EDC of the 944 PCGB forums?) thanks. Are the Spyder Porsche ones made by the same people as the Meyle ones to the same spec? If so then I'm interested .... 

 

- Red Rocket - Max of Frazerpart seems to be the best source of the Meyle ones. Thanks for pointing out the details in the 'Details' tab on their website. Thanks also for the link to the PET diagrams. Why are you starting with the ARB bushes and drop links? 

 

- Tony, that's properly useful stuff, thanks. You've mentioned a different set of parts - front tuning forks and rear toe links. Have you done the coffin arms previously? 

 

The point about the cost of alignment is a good one. My problem is that the car has been a money pit since I purchased it; air con condensers, coolant pipes at the front, oil for engine an gearbox for a service ... I'm getting on for a grand in and have yet to do 3000 miles in it. The clunks from the front suspension are the icing on a pricey cake and I'm trying to economise. Having said that I can see the argument that doing half a job is a false saving so maybe I should be doing more than just the coffin arms. 

 

If this is the case then what should the shopping list have on it? Coffin arms and tuning forks? What about some drop links at the front? I think I'll limit things to the front for now so the rear toe links will be missed off. What about tie rod ends at the front - are those worth doing? 

 

I really hope that this car is worth it in the end. Thanks again for your help. 

 

[Tony Daniel]

You can probably do the front suspension arms without the need for alignment afterwards. Drop links I've never replaced so cannot comment. Coffin arms ball joint you can sometimes detect with car on a stands with the wheel off. 

Is there any clunking on the rack? Could also be track rod ends😕. 

Can you not take the car to a Porsche specialist and let them analyse it for you before you start part swapping? 

[zcacogp]

Tony, 

 

I don't actually know how the geo is adjusted on the front of a 987 so don't know what parts would necessitate a geo check once replaced. Toe-in and out would be with the tie rod ends but caster and camber adjustments must be somewhere. 

 

There is clunking from the front generally - whether it's from the rack or elsewhere I don't know. I do know that when parallel parking it the other evening it was crunching like it was parked on gravel and it can sound a little tappy when driving over bumps. One thing that occurs to me is that I dropped the front subframe almost all the way out when doing the coolant pipes last week so it is possible that I didn't do something back up again properly. 

 

Taking it to a specialist for an assessment is an option but it's all cost; instead of spending £60 with them for an hour's labour I could spend that £60 on some new parts. I am aware that the car is about to tick over 100,000 miles and there is no record of any suspension work having been done so the parts are probably due for a change soon anyway. 

 

Thanks again for your help. I'll talk to Spyder Porsche about their coffin arms and tuning forks and maybe some track rod ends. I'm seeing a friend with a pit and a good workshop in a couple of weeks time to change the air-con condensers so maybe we could fit in a front suspension parts change all in the same day. 

[edc]

I've not had a 944 so different person. I spoke quite a few times to Dean as they were setting up their Spyder parts and business. Their arms are to their own spec. What that is I don't know. But at the time the supplier was Meyle. 

[red rocket]

10 hours ago, zcacogp said:

Why are you starting with the ARB bushes and drop links? 

From what i've read here over the past couple of years arb bushes can often be a cause of knocking noises. Changing them is supposedly a relatively easy process so  ( as my spannering skills are limited) i'm starting there. My car is on 93000 miles so definitely likely to need the suspension refreshing.

[red rocket]

15 hours ago, Tony Daniel said:

Front 'coffin arms' on are 987 are different to the rear and different to a 986. I have used OEM and no OEM arms and not found any difference although speaking to Jasmine today they say they have issues with the none OEM ones been a millimeter longer which can throw out alignment. 

I have just replaced the front and rear 'tuning forks' and rear toe links all in one hit as a lot of the cost is in your alignment afterwards. I'm using Spyder performance front arms for the first time so we will see how they last

You can replace the rubber bushes in the coffin arms, but not the ball joint. So I wouldn't recommend doing this with old arms

Tony, can see from your posts in this thread and elsewhere that you've done alot of suspension work. Do you have the relevant torque settings for the various components or can you point me in the right direction? I've seen various supposed workshop manuals advertised online but it's impossible to know whether they are actually any good. I already have one that's posted somewhere on here from workshop-manuals.com but all that says in the suspension section is to follow the recommended torque settings. I'm sure i'm not the only one with this problem.

[The Caped Crusader]

I purchased coffin arms from Hartech. They sell genuine Porsche ones which they have shipped to Germany and refurbished to the OEM spec. 

I would say the tuning forks get loose and are well worth changing. 

Personally, I would remove the whole strut assembly. You can then examine all the suspension properly to see what needs replacing. Top mounts don't last forever. 

Also, with all the bits off the car, you can check the drop links by hand for free play. Same with the track rod ends. With the drop links removed on both sides you can check for any play on the ARB bushes too. 

It's probably just over an hours work to strip each corner. There are only two things you can adjust on the front suspension I think: the track rod ends for the steering and the top mounting for the strut. Everything else is fixed. 

[zcacogp]

CC, 

 

Thanks. That's helpful. If those are the only two adjustments possible then how does the suspension get set-up? Track rod ends will give toe, what adjustment does the top mounting allow? Camber AND castor? I can see that this would be possible but didn't know that they adjusted at all. 

[Nobbie]

1 hour ago, zcacogp said:

CC, 

 

Thanks. That's helpful. If those are the only two adjustments possible then how does the suspension get set-up? Track rod ends will give toe, what adjustment does the top mounting allow? Camber AND castor? I can see that this would be possible but didn't know that they adjusted at all. 

If they are like the 986, then the holes for the top mounts are slotted horizontally so only allow camber to be adjusted on the front.

[entdgc]

2 hours ago, The Caped Crusader said:

There are only two things you can adjust on the front suspension I think: the track rod ends for the steering and the top mounting for the strut. Everything else is fixed.

Isn't there an eccentric somewhere in the system. Yet to work on the suspension but I am sure I have read about one somewhere (perhaps the rear?).

[Nobbie]

12 minutes ago, entdgc said:

Isn't there an eccentric somewhere in the system. Yet to work on the suspension but I am sure I have read about one somewhere (perhaps the rear?).

If it's the same as the 986, then there are two eccentrics on the rear for camber and toe with the top mount fixed in position.

[entdgc]

6 minutes ago, Nobbie said:

If it's the same as the 986, then there are two eccentrics on the rear for camber and toe with the top mount fixed in position.

Ah thats good to know! My front near side has the 'bag of snookers balls' noise and I have been putting off looking at as it still seems to handle OK and I had heard these eccentrics can be a bit of a pain to dismantle...

[Boxob]

12 hours ago, zcacogp said:

I do know that when parallel parking it the other evening it was crunching like it was parked on gravel ....

That might have something to do with the Ackerman effect.

[zcacogp]

4 hours ago, Nobbie said:

If it's the same as the 986, then there are two eccentrics on the rear for camber and toe with the top mount fixed in position.

'On the rear' as in on the rear suspension, as opposed to being located on the rear of the front suspension - non? 

[zcacogp]

2 hours ago, Boxob said:

That might have something to do with the Ackerman effect.

Doubtless, but then many issues with steering are Ackermann related. 

 

It's certainly not as it should be. Although I am wondering whether it is simply that I didn't do something up tight enough on the front subframe when it was lowered last week. I think I need to get it all up in the air again and have a good snoop 'round. 

[Nobbie]

14 hours ago, entdgc said:

Ah thats good to know! My front near side has the 'bag of snookers balls' noise and I have been putting off looking at as it still seems to handle OK and I had heard these eccentrics can be a bit of a pain to dismantle...

They were on my car, I had to use a reciprocating saw to cut through them as the aluminium/steel interface had corroded solid.

 

10 hours ago, zcacogp said:

'On the rear' as in on the rear suspension, as opposed to being located on the rear of the front suspension - non? 

Yes, on the rear suspension.

[Tony Daniel]

23 hours ago, red rocket said:

Do you have the relevant torque settings for the various components or can you point me in the right direction? 

I tend to just google what I'm doing at the time and the answers are usually on Renntech. Thinking about it though it would make a great 'sticky' thread listing torque setting for various components. 

[Nobbie]

https://workshop-manuals.com/porsche/boxster_(986)/f6-2.5l/steering_and_suspension/suspension/control_arm/component_information/specifications/front_suspension/

This is what I found for 986, expect their is a 987 section as well.