Some assistance and reassurance please

[DavidL]

Whilst enjoying the KW debate I decided I really needed some more suspension to use whilst I made up my mind. I managed to pick up some relatively unused (20K) stock turbo suspension from the same model year as mine. Cheap as chips (£100 all 4 corners). I am determined to change them myself and started today.
So I managed to get the rear lower nut loose but the top one is a bit more difficult.

Will some kind soul just reassure me:
The nut on the outside of the inner wheel arch is the one I should be trying to undo for the top mount not the one tucked up close to the bodywork underneath. Its the same bolt just different ends - I think. There is a picture in the Haynes manual (not the best I know but it does give one or two pointers) but its effectively upside down?
This bolt has done 20 years and 200K (I told you the suspension was fubared) so presumably changing it would be good - what with?
When I take the lower bolt out even if the damper is compressed a little by a jack presumably the whole trailing arm will drop - do I need to be particularly careful here not to damage the disc on the floor as it drops?

I haven't got to the front yet but the replacement parts are complete except the top mounts. Presumably I can remove mine and take the top mount off one and put it onto the other without have to touch the spring?

Fortunately I don't need the car for transport so it can sit on axle stands for a few days. I know its not really a hard job but there is much satisfaction in doing a few bits yourself rather than driving to the indie with a boot full of bits and saying there you go fit those!

Any advice much appreciated, especially on getting the damn bolts undone!

David

 

[mik_ok]

David,

Presumably you're talking about the rear dampers in the first part of your question (?) ~ in which case no the trailing arm will barely move when you remove the damper. I seem to remember having to jack under the hub to raise it a few mm to fit the new ones though.... Top bolt is a PITA - leave the lower one in whilst you attack it.

Top mounts - yes I believe you are correct.

 

[elvis]

At the rear the trailing arms won't drop because they are still attached to the torsion bars. It's not like coil springs where the springs come off with the dampers, the 'springs' are actually in the cross tube about a foot forward of the rear wheels. You'll need a jack under the arm to line up the damper mounts when you put it all back together though as per mik_ok's post above.

You'll need to undo the bolt right up in the rear wheel arch while holding the other end up under the car. If you stick your head under it should be fairly obvious that it's the same bolt. Mine were 19 years old and came off with a breaker bar, soak them in plus gas and wire brush the threads first if they look really bad.

At the front you'll need spring compressors to get the top mounts off. There's been a thread recently on this here.

Clark's Garage here is the best 944 technical resource I've found, you can also download the excellent factory manuals from Rick Cannell's site here.

Good luck, and remember to get the geometry reset if you split the front struts.

---

Edit: Just reread your post: you need to take the top damper mount bolt out so you need to undo both the inner and the outer if you get what I mean. You're probably best off going to Porsche for the bolt, it's M12, grade 8 according to the manual so not impossible to get hold of but the length (overall and shank) will be fairly critical as space is tight and you really don't want the damper forces on a threaded portion of the bolt (stress risers and all that..)

 

[edh]

If you ring those nice chaps at Exeter Porsche they will send you some shiny new nuts & bolts [] They have started charging £2.95 postage now - so not quite as cheap as they were.

- If you know exactly what you need, then you can get them cheaper off ebay.

 

[DavidL]

Cheers chaps, at least that confirms my assumptions mostly.
Just to confirm one more point the top mount (rear) appears to be a bolt head (pointing out at you from the inner wheel arch) and the nut seems to be the one on the "inside". Is the nut captive or am I trying to get the bolt to turn without holding the nut? I haven't got the car high enough to be able to see this inner nut but it does feel quite rusty - its all soaking in WD40 currently till tomorrow pm. Is this plus gas stuff better? Normal motor factor supply?

ETA Page 42-04 of the workshop manual has a little schematic of the rear shock and seems to suggest that the bolt of the lower mount points towards the centre of the car (ie not the wheel) and is captive the other end - no nut. This makes sense as the bolt clearly goes into the structure.
But the top mount is again a bolt head facing in and what I assumed above is the bolt head is actually the nut so I must just try a bit harder to get it to budge!!
At least once I've done one side then the other should be a bit easier and then I'll do the front!

 

[zcacogp]

David,

Rear top bolt - as I recall, it is the one nut visible in the rear wheel arch, but find the other end (on top of the shock) and you'll easily work out how it all fits together. It is just a nut and bolt, nothing more. It only fits one way, if I remember, with (I think) the bolt head on the outside and the nut on the inside, so the bolt faces into the centre of the car.

Plus gas (in my experience) makes WD40 look like water in terms of effectiveness.

Bottom is a bolt that goes into a tread in the trailing arm. No nut - the thread is cut into the inside of the hole. The trailing arm will drop a fraction (1-2cm, perhaps), but not a lot. You will need to jack it slightly to get the shock back on.

BUT

It sounds like you are swapping one worn set of suspension for another (semi-worn) set, as a half-way house to KW's. I'd save your time and money - the set you are fitting will be awful (worse than the existing set) if you don't get it aligned properly, which will cost around £100. And you will need to get the KW's aligned when you fit them as well ... why not stick with what you have got until going the whole hog with the KW's?


Oli.

 

[DavidL]

Oli,
You are absolutely right. Ordinarily I wouldn't countenance preowned shocks but mine are dreadful - one front one rattles. These just happened to come up very close to a very car savvy friend of mine who had a look and as he said apart from a bit of dust they look virtually new.
The argument of spending £200 for the shocks as opposed to putting the money towards KWs is very valid but since I have a couple of other bits to spend money on I've decided on this for now. Also still awaiting the re-index discussion too as that potentially adds quite alot.

 

[James_G]

David

I have just spent the last two days doing this job, so here's my tips for making it a success.

Rear Shock
As the others have pointed out, there's a nut and bolt arrangement at the top of the damper and a single long bolt at the bottom. At the top, the bolt goes through the wheel arch, through the damper and then is retained by a nut, which you can't see until you are under the car. An open ended 19mm spanner on this end, and a 19mm socket with an extension for the other end (so you clear the wheel arch) and it will come undone. It's a tricky one person job, better to have somebody holding the spanner under the car, and somebody applying torque to the wrench outside. I haven't replaced the bolt here, but I have replaced the nuts, and they aren't very dear, £0.50 or so each from an OPC.

The bottom bolt is just screwed into the rear trailing arm, there is no nut. This is 22mm and a bit of a beastie. It took a few hits with a club hammer but came undone easily enough after that. I have kept the same bolt here.

Front Shock
This was easier to get off the car as there's just two bolts at the bottom and strut top mounts in the engine bay. Go very careful with the uppermost of these two bolts though as it's an eccentric bolt (for camber adjustment) and expensive to replace, if like me you shear one off (£8.50 inc VAT each!). Lower bolt is 19mm, as is its retaining nut. Eccentric bolt is 17mm, retaining but as before 19mm. As I was ordering a new eccentric bolt, I ordered another for the other side and also two new basic lower bolts, to go with the new nuts that I already had. They are lock nuts and I would definitely recommend replacing them even if you don't replace the bolts.

Strut top mounts are 13mm and are very easy to undo but soak in PlusGas as shearing one of these off would mean buying a new strut top and that way bankruptcy lies. Again new bolts and washers here are just pence each. I think the washers were more expensive than the bolts!

Once the shock is off, you'll need to undo the nut holding the strut top onto the strut rod which will require you to compress the springs. Again it's a 22mm nut, and you may get lucky by shocking it off, but in the end I had to use mole grips on the rod and that club hammer again. That's fine for removal, but not ideal for installation. As per the thread I started recently the elegant way to rebuild you struts is to have a 22mm swan neck spanner and a 7mm allen key socket that you then put in a torque wrench. Use that to hold the rod still while tightening with the spanner. I didn't have this arrangement (my new 22mm swan neck spanner is in the post!) so I used a 22mm socket gripped by mole grips and the aforementioned torque wrench arrangement. Hard work, but did the job. While doing this you may wish to replace the dust boots. I have no idea how much they are, but I wish now I had done it as the old ones look very tired next to my nice shiny struts.

Once done the strut went easily back in position but again it's easier with two people, one working above in the engine bay and one below inserting the bolts.

Top tip of the day is to take photographs of your camber adjustment bolts before you undo them and that way you can reset them as before, so that your setting will be near to what they were when you started. As others have said though, do pay for a full geo as soon as you can.

Hope that all helps.

James

 

[zcacogp]

Excellent advice there from the handsome chap in the Black S2. []

I've embedded some comments below.

I haven't replaced the bolt here, but I have replaced the nuts, and they aren't very dear, £0.50 or so each from an OPC.

They're just nuts ... find a local fastener supply company and they will be nearer 2p each. M8 from memory. Get some stainless ones and they'll stay shiny! (Buy a bag of 100 and you can then replace the nuts and bolts in future jobs as well. That makes things look a lot smarter.)

The bottom bolt is just screwed into the rear trailing arm, there is no nut. This is 22mm and a bit of a beastie. It took a few hits with a club hammer but came undone easily enough after that.

Go slightly easy here. The thread it goes into is cut in alloy, not rolled on steel. It won't be *that* strong. Hitting the spanner with a club hammer sounds a bit brutal ... try a long breaker bar instead.

PlusGas

[]

While doing this you may wish to replace the dust boots. I have no idea how much they are, but I wish now I had done it as the old ones look very tired next to my nice shiny struts.

I know what you mean, but you won't see them when the car is back on it's wheels. As long as they are intact enough to carry on doing the job all will be well.

it's easier with two people, one working above in the engine bay and one below inserting the bolts.

Real men do it single-handed [] (as the bishop said to the actress ... !)

Top tip of the day is to take photographs of your camber adjustment bolts before you undo them and that way you can reset them as before, so that your setting will be near to what they were when you started. As others have said though, do pay for a full geo as soon as you can.

A scratch with a scribe to show the position of the eccentric on the strut does the same job, but everything else will have moved in the process (and the new parts will be a slightly different shape to the old ones) so getting it properly set is essential. (I found the geo made more difference to the way mine handled than the new suspension.)



Oli.

 

[DavidL]

Thanks both that just about covers it I think.
I resorted to using leg power to get the bottom nut undone - it came away with a distinct crack. Fortunately not broken just undone.

Paul M - might it be worth picking the info bits out of this (ie not my bits!) for the FAQ. I would think there is sufficient info to allow most people to get this done now.

 

[Neil Haughey]

Are we sure they are not steel lock nuts? rather then just plain nuts. ISTR my brother saying the ones on the front look like steel lock nuts, can't recall what the rear ones look like. Personally I would never ever risk using some of the shelf nuts and bolts on critical vehicle components unless you are 100% sure they are of the same or better spec then factory originals. After all we are only talking about a few pounds here and there.

The workshop manual also gives hints as to which nuts and bolts require replacement on the notes column next to the torques for each item on the big items list tables in each section.

 

[elvis]

The manual will advise replacement if the bolts are lock nuts (you shouldn't reuse lock nuts). I'm 99% sure they're just plain nuts, I know I reused mine and I'm normally fairly careful about these things.

Stainless will look pretty but I'm not sure it's a good idea in a stressed application as stainless has different properties to 'normal' steel and then you are definitely deviating from factory spec. Will probably be OK but might not. I don't use stainless anywhere where failure would cause an accident, but that's just me.

 

[James_G]

It all depends on how close you live to an OPC and how much you value your time versus saving a few £s. Shearing a bolt on Monday has caused me no end of trouble, (partly to some spectacular incompetence from Reading OPC), so I couldn't imagine taking the risk of not having quite the right nuts, getting the car to pieces and then having to put it all together to drive to the nearest OPC to buy the right ones.

So I took a judgement and figured I should replace all the nuts with Porsche supplied ones which probably cost me £3 all in, compared to say 50p.

Of course I hadn't assumed I would need new bolts.[]

 

[DavidL]

Ok chaps so a reasonably productive week. Both rear dampers replaced, no dramas excpet trying to get the nuts undone.

First front strut off today.
Main issue is that the replacement strut does not have a top mount. Looking at the 2 side by side the new one simply has the top spring holder held on by the 22mm nut. I'm guessing when the struts were replaced the rest was reused.
I didn't want to have to dismantle the the damper but it looks like I'm going to have to.
Correct me if I'm wrong:
I can't get the top mount off without taking the 22mm nut off (and everything else comes off with it)?
Is the spring going to fly across the drive? I shall use the elegant method shown in James's thread with the goose neck spanner. Off to get one tomorrow.

Am I going to be able to get the nut back on without a spring compressor?

What should I replace? I have ordered new nuts and bolts for the front struts (Porsche no longer supply the rear bolts but they did give me the spec) and I shall go back to them for 2 new dust boots and top mount gaskets. Anything else?

I too will need the ABS and brake pipe holders. There doesnt seem to be a way of getting the old ones off, either that or the plastic is just too brittle now.

James that nice ali jack you have. I'm assuming its man enough for the job as I'm sure its only rated to a little over a tonne? It would be a good choice as nothing else I've seen will slide under my Caterham let alone the 944!
My year old Halfords trolley seems to have a an air leak and won't lift anything - PITA for jobs like this.

Again thanks in advance.

 

[mik_ok]

If you are stripping the strut down you most definately need a set of spring compressors.

You should be able to rent a set if desparate, but they aren't expensive (see HERE for example)

 

[zcacogp]

Sounds like good progress. Well done.

James' thread is a good primer on how to do the job. Follow it and you will do well.

As Mik has said, Spring Compressors are an essential. Don't try and do the job without a set - you will damage something (quite possibly yourself) if you try to take the assembly apart without compressing it, and you won't get it back together without a set either.

You can replace as much or as little as you like. You will find that the top mounts are VERY expensive (especially when you realise how simple they are) and you may choose to re-use the old ones, as I did. Dust covers can be replaced if you like. Nuts/other bits, as you choose.


Oli.

 

[tr7v8]

Top mounts are well over 200quid each.... And OPC only. There is a lot of pre-load on the springs & you need to be careful using the spring compressors. One top mount I did was FT &
we struggled to get it undone off the car & actually broke the other one before stripping the strut ff the car.

A word of warning on the trailing arm bolt, they are Metric fine M17 x 1.25 from memory, NOT standard metric & go into a steel insert in the arm If you don't support the arm
then as it drops it will mangle the thread AMHIK! The top shock bolt has a nyloc on the inner side & should be replaced. Unless you have an orang-utan in the family tree then I can't see how you could do it on your own!

 

[DavidL]

Thanks all. So spring compressors on tomorrows list along with a 22mm swan neck spanner. I shall have to ask Exeter to send some fixings along with the front bolts I have already ordered.
Any advantage to changing the top mounts? I doubt I will but IIRC Nick changed his for Racers Edge ones?

 

[Mike_Pollock]

I have a socket set which has the drive on the outside of the socket, which leaves a large hole in the middle allowing a hex headed conventional socket to be used at the same time. I got the set 'cos it looked good ... no ... its the only way to get my Galaxy front struts out - they are UNDER the front edge of the windscreen. Noted as an alternative the the 22mm ring spanner..

The external drive sockets are really good and try as I might i've not damaged any of it yet. I have sheared 2 quality 1/2" drives.

Mike

944 - 1983 - White (mostly)

 

[sawood12]

ORIGINAL: DavidL

Thanks all. So spring compressors on tomorrows list along with a 22mm swan neck spanner. I shall have to ask Exeter to send some fixings along with the front bolts I have already ordered.
Any advantage to changing the top mounts? I doubt I will but IIRC Nick changed his for Racers Edge ones?

I've got racers edge top mounts and they are great. It is difficult for me to assess what benefit they are contributing to as I had them installed at the same time as my KW, but the turn in of the car now is very responsive, and the feel and feedback mid bend is very positive with the car tracking perfectly in response to steering inputs. Very confidence inspiring. Also i've not noticed any significant deterioration in ride quality, but they do transmit some minor noise from the suspension when manoeuvring at slow speeds with alot of lock e.g. in car parks.

In any case they've got to be better than 20yr old rubber mounts.