996.1 Clutch replacement - job list

[richthebike]

Hi all.
As many of you know, I picked up a 96k mile 996 earlier this year.
Have done about 1100 miles, and the clutch is on its way out. I'm not getting into whether that's a good condition for a dealer to sell a car in, and I don't really want that debate.

Car is used on the road twice a week, not as a daily, but I'm gearing up for a couple of track days a year (once my dad has sorted himself something suitable too).

I wanted to check latest thinking on 'what to do at the same time as a clutch'.

- worth replacing / upgrading the flywheel?
- what's the latest thinking in Oil Fed IMS / if it looks fine then why change it debate?
- worth bothering with an LSD (Wavetec or similar); I don't feel the need for one, but whilst I'm in there I might as well, then I know it's all refreshed
- replace the underbody plastics because they're extremely scruffy


Thoughts / what have I missed.
Thanks all RTB

[EGTE]

Remove IMS dust shield (Hartech recommendation).

See post 3 onwards of this very useful thread:

http://www.911uk.com/viewtopic.php?t=108257

[bgunn]

If you can afford it, get the gearbox rebuilt with a new pinion bearing at the very least - the originals fail and cause a whine. Similar thing, pop off the dust seals on the new one.

Sport and Classic are supposed to be the place for this - plan to do mine soon as the FD whine is just starting.

[interstellar]

When you say "on its way out" is it just difficult to get into first and second or something different as this is common?

If so, have you checked the clutch spring as these are worth changing as they get broken or stiff and it makes a huge difference.

I may be off the mark as I cant tell by your post but was worth mentioning.

If it is just stiff then the clutch spring may sort it.

[BrotherMouzone]

interstellar said:

When you say "on its way out" is it just difficult to get into first and second or something different as this is common?

If so, have you checked the clutch spring as these are worth changing as they get broken or stiff and it makes a huge difference.

I may be off the mark as I cant tell by your post but was worth mentioning.

If it is just stiff then the clutch spring may sort it.

+1

Also IIRC there is a thread on 911uk recently about checking the slave cylinder if your clutch is heavy.

Mine is at 85k+ miles and I track my car also. No slip and reasonably light.

[996lee]

I'm imagining like mine at similar mileage this is it's 2nd replacement clutch and at 100k mine was starting to slip
So decided to replace the flywheel for a lightweight version and to reduce a bit of the chatter at idle a sprung clutch



Had this fitted for about 4k now and am still loving the mod
Revs up so much quicker than before

I read lots of stuff on forums about getting flywheels balanced and single mass not damping as much as the dual mass but i couldnt see it being any worse than a dual mass that had done 100k miles

[richthebike]

Thanks for all your replies, very helpful.

The clutch isn't heavy and it's not tricky between the gears. It has become harder to modulate, is grumbling a bit and whines on release when hot.

The box is much much quieter than my last C2, and feels sweeter. In general the transmission is less whiney.

Good to hear from a flywheel upgrader. I'm tempted to do it whilst I'm in, mostly so I know it's all done.

I'm away with work this week, getting a few indies to weigh in and price up. Will update accordingly...

[richthebike]

EGTE said:

Remove IMS dust shield (Hartech recommendation).

See post 3 onwards of this very useful thread:

http://www.911uk.com/viewtopic.php?t=108257

Thanks for the link, very informative

[richthebike]

So, having cast around and read quite a lot of opinions, I have agreed the following job list with my favoured indy:

- OEM Sachs clutch
- EPS IMS bearing
- Lightweight flywheel
- RSS semi solid engine mounts
- Refreshed gearbox bush / powerflex mount
- RMS, flywheel and clutch sundries
- braided brake lines all round
- replace some underbody plastics

I've put the Wavetrac LSD on hold because I don't really need it on what is predominantly a road car, it's the best part of £2k fitted and can be done standalone at a later date.

I'm reconciled that this little lot is going to be the best part of three and a half grand, but 'whilst I'm in there' upgraditis struck and there's no overcoming it.

Next jobs will be removing some more weight, maybe some buckets, then a service in the spring. Maybe a ducktail at that point too.

Suspension is good, just had the alignment and brake servo done.

Looking forward to getting it all done so I can get the car back in use!
More to follow when I get it back. Thanks for the help so far.

[bonus99]

Thanks OP for the thread, I have my 98 C2 200k going in for clutch and flywheel in three weeks and Ill look in to some of this. It had a small rebuild for a broken valve spring at 155k and the IMS was not noisy and "let sleeping dogs..." was my decision. This time round though, might just get it changed.

[fot0]

Think you noted above, but check condition of brake pipe over bell housing. Can be fixed in-situ, but it's a pig of a job. If you're taking the wheel liners out, check for rust forward of the rear wheels. These cars are well protected, but age is showing evidence of corrosion if not treated now.

[Rockster]

richthebike said:

Hi all.
As many of you know, I picked up a 96k mile 996 earlier this year.
Have done about 1100 miles, and the clutch is on its way out. I'm not getting into whether that's a good condition for a dealer to sell a car in, and I don't really want that debate.

Car is used on the road twice a week, not as a daily, but I'm gearing up for a couple of track days a year (once my dad has sorted himself something suitable too).

I wanted to check latest thinking on 'what to do at the same time as a clutch'.

- worth replacing / upgrading the flywheel?
- what's the latest thinking in Oil Fed IMS / if it looks fine then why change it debate?
- worth bothering with an LSD (Wavetec or similar); I don't feel the need for one, but whilst I'm in there I might as well, then I know it's all refreshed
- replace the underbody plastics because they're extremely scruffy


Thoughts / what have I missed.
Thanks all RTB

What makes you think the clutch is on its way out? Does it slip?

BTW, if this hasn't been done recently have the brake and *clutch* fluid flushed/bled. Two times now with my Boxster this has made a noticeable difference in the clutch's action and in transmission shifting (because the clutch was fully disengaging after the fluid flush/bleed).

If the clutch needs doing replacing the flywheel is a tech's call. He should be able to judge by the flywheel's condition whether or not it can be resurfaced or not and if it is otherwise reusable whether the dual mass feature is working properly. There's a test for this and the tech should perform it unless he has to trash bin the flywheel for other reasons.

Can't help you regarding the IMSB.

I can add the engine can benefit from some intelligent modifications to help prevent (or lessen the possibly of) oil starvation under high g-forces encountered on the track. A deeper oil sump with better/more robust baffling coupled with a longer oil pick up tube for instance.

Installing a 3rd (center) radiator if the car is equipped with just two helps the cooling system handle the increase in heat load better. Be sure the radiator ducts are kept free of trash and always show up at the track with fresh oil.

Can't help you with the LSD question. Any LSD you choose would have be a very good one to withstand the rigors of tracking unless you want to possibly "refresh" the LSD maybe once per year at the start of the tracking season.

The only time I replace any under body plastics is if one gets damaged. Occasionally -- not very often but every 4 or 5 years maybe -- I or the tech finds one damaged like a hole punched in one from road debris. Or one is torn loose and hanging again from some road debris catching the panel.

It is important the under body panels remain properly secured and intact to perform their critical function so I replace when one becomes loose or just damaged. On my Boxster I've even had to replace at least one plastic panel topside. The cowl panel faded horribly but when it started cracking and became loose that signaled it was time to replace.

But replace because of just being scruffy? No. Hell no. They get scruffy pretty darn quick and you'd go crazy (and probably broke) keeping them pristine.

[richthebike]

Thanks for the replies.

Principle issue with the clutch is that the release bearing has checked out. I'm not sure about failure modes and pedal feel, but I do know bearing death when I hear it. I have no evidence of a clutch replacement in 97k miles, and it's now a complete pig to feed in. So, we're going in...

To be honest, I've heard good things about lighter flywheel, and this isn't a daily, so I want to give one a go. Had I not been doing the clutch, I wouldn't have bothered. But again, we're in, so I'm going to give it a try.

Braided lines have been on the list for a while, and my Indy advised to do the rear over the bell housing anyway, so I'm doing the lot.

Engine mounts... I'm hoping will give a bit more rawness and control. I've read good things about the RSS semi solids. Let's see.

Likewise, the shift is actually very good, but the gearbox mount and bush are meant to tighten up further. Will report back.

Imsb. Tough call. Have taken the advice of the man who looks after my car, and who looked me in the eyes to explain how many of these he's done (lots), and how many have come back (none). I hear the advice in letting sleeping dogs lie, but have mulled it over with my man, and this is where we're at.

Underbody plastics... I enjoyed your summary. Let's say some of them are snapped and a bit flappy, one is clinging on, and a couple have seen better days. They're a consumable item, and should be replaced. Reminds me of my gt3 front splitter!

Other track upgrades are on hold. At most I'll be doing a few a year, and I'm no racer. I've tracked an MR2 and an R26 Megane for a bit, but I'm not very quick and it's more about being able to spend some time with my dad. He races an exige and it's a good boys day out. The 996 will be on road tyres etc. And doing short runs at 8/10ths, so not expecting race conditions.

I do love a project, and I love a feelsome car. I've been thinking about getting an Elise or a Morgan 3w for an occasion car, but think a fettled 996 ticks more boxes for me, and keeps the cars on drive factor lower.

Obviously it's easy to get carried away. Do I need a set of Ohlins and a ducktail? No. But the want is strong anyway!

Thanks for your comments
RTB

[sundayjumper]

Re: the shift, and independent to the clutch job, but I've just fitted a stock 987 shifter (s/h from a low mileage car) to my 996. It's slightly shorter but the big difference is in how much slop the original had developed over the years ! Eighteen years and 112k miles take their toll. It's a cheap/easy upgrade.

[jonno_]

While your (indie) is in there, why not get the 'box oil changed too?

On the cooling side, it's probably worth the latest expansion tank cap and checking the tank itself for leaks. Water pump ok?

[richthebike]

A quick update...
I have the car back, only driven it 10 miles home, but a) the clutch now works and b) it feels tight as a drum now all the mounts are done.

Huge thanks to Matt at PorschaCare in Hitchin / Stevenage. He's a top bloke.

Planning the next list of upgrades now. Suspension in the spring I think.

Will report back on lightened flywheel and RSS semi solids when I've had a proper drive.
Apparently IMS was a little notchy but looked ok. It's not in the car any more, so that's immaterial!

[EGTE]

Great result, well done.