Omg IMS news I didn't want to hear.

[Photogirl]

Aside from the fitment issue, I'd be interested to know if it was in fact compromised in its function, or worn/damaged in the same way as a properly fitted IMS would be. 

[Menoporsche]

There was a phase about 5 years ago where several people replaced their own, or asked the garage to replace it.  Interesting to know if this was such a replacement or the original from way back when.

If the original and it was 20 years old, that suggests that function wasn't much compromised!

[Photogirl]

I'd be interested in how many of the replacements have failed. Would all the replaced bearings be of a 'reinforced' design and if so does that mean you're largely protected going forward? I've heard of a couple of incidences where a replacement did fail (catastrophically) but I'm not sure of the particulars.

[edc]

6 minutes ago, Photogirl said:

I'd be interested in how many of the replacements have failed. Would all the replaced bearings be of a 'reinforced' design and if so does that mean you're largely protected going forward? I've heard of a couple of incidences where a replacement did fail (catastrophically) but I'm not sure of the particulars.

There are various different replacement bearings including like for like replacement so it's wrong to assume a replacement bearing is a stronger or reinforced one. 

There are stories of replacement failures but for the most part you won know why it failed. Most will cite poor installation. But, if the root cause isn't the IMS bearing failing first itself then there can be some other engine fault that shows up as extra stress and the bearing going. Any replacement bearing will likely fail again. 

[Photogirl]

11 minutes ago, edc said:

 if the root cause isn't the IMS bearing failing first itself then there can be some other engine fault that shows up as extra stress and the bearing going. Any replacement bearing will likely fail again. 

Thanks - that's interesting. I had always assumed it was down to the bearing itself being weak or poorly designed, and not coping with periods of low/uneven lubrication. I'm wondering what engine faults might lead to the IMS failing (though from what I've heard it doesn't seem to be related to bore scoring).

[½cwt]

18 minutes ago, edc said:

There are various different replacement bearings including like for like replacement so it's wrong to assume a replacement bearing is a stronger or reinforced one. 

There are stories of replacement failures but for the most part you won know why it failed. Most will cite poor installation. But, if the root cause isn't the IMS bearing failing first itself then there can be some other engine fault that shows up as extra stress and the bearing going. Any replacement bearing will likely fail again. 

And an important note, the pictures you kindly linked to are the later single row bearing that does not have the groove that is in the earlier dual row ones up to mid 2001 Model Year.

[Tonybandit]

4 hours ago, ½cwt said:

Looking again I can see the groove in the picture on the web link I posted above.  Don't suppose anyone has pictures showing the spring clip and the groove on the shaft?

Short answer, it is handed and therefore can be fitted the wrong way round...

They did say that the spring clip was also not fitted correctly and broken. 

I've still not got my car as I did say I wasn't in any rush to have it back. 

As soon as I do get it back I will get more info for you all. Its deffo been an eye opener and the guy at Revolution did say he had never seen it before and has fitted way to many to count. 

[tonyplymouth]

The dual-row bearing is secured with a plain spring wire clip; basically spring wire bent into a C-shape.

The later single-row IMS bearings are secured in place with a Circlip set against the bearing and into a groove in the shaft.  So it doesn't matter which way round a single-row bearing can be fitted.  

The groove for a plain spring clip is slightly narrower than that needed for a Circlip of the same basic diameter.  In the case of at least one aftermarket dual-row replacement option, where a single row bearing and a spacer is substituted, the arrangement is secured with a Spiroloc spiral retaining ring; the Spiroloc better suits the narrower groove in the shaft originally intended for the spring wire ring used with a dual-row bearing.

[Tonybandit]

So I've got my car back after a new RMS IMS and clutch plus flywheel. 

I didn't realise how stiff my clutch peddle was till now.

So the guy at Revolution said that I've been lucky and the flywheel and clutch was at the end of its life.

The IMS was put in with the clip to the wrong side so it has been pushed in and broke the clip that is on the bearing. I have a duel row bearing and now have the LN upgrade ceramic bearing. Am I glad I've had this done.

Also the clutch was an AP clutch, if anyone knows what that is, but it had been changed at some point in its life. I don't have any paper work for it but I'm glad I didn't as I'm not sure I would have changed it till it was too late. 

I'm now going to try find the past owners so I can get some info on who fitted the IMS and the clutch. 

So if anyone knows this car, it's reg when I bought it was Y188 NBY would be greatly appreciated. 

[½cwt]

AP = Automotive Products.  One of the top clutch and brakes manufacturers so no worries.

[Corsica13]

4 hours ago, Tonybandit said:

So I've got my car back after a new RMS IMS and clutch plus flywheel. 

I didn't realise how stiff my clutch peddle was till now.

So the guy at Revolution said that I've been lucky and the flywheel and clutch was at the end of its life.

The IMS was put in with the clip to the wrong side so it has been pushed in and broke the clip that is on the bearing. I have a duel row bearing and now have the LN upgrade ceramic bearing. Am I glad I've had this done.

Also the clutch was an AP clutch, if anyone knows what that is, but it had been changed at some point in its life. I don't have any paper work for it but I'm glad I didn't as I'm not sure I would have changed it till it was too late. 

I'm now going to try find the past owners so I can get some info on who fitted the IMS and the clutch. 

So if anyone knows this car, it's reg when I bought it was Y188 NBY would be greatly appreciated. 

Hi Tony,

Thanks for sharing your insights.

I'm looking to buy my first 986 S very soon and was wondering how much this kind of job costs as it may be something I need to consider in the near future, specifically clutch + IMS.

Many thanks,

[Tonybandit]

13 hours ago, ½cwt said:

AP = Automotive Products.  One of the top clutch and brakes manufacturers so no worries.

I wasn't sure if it was that good but the question is, fit a top clutch and then do shoddy work fitting the IMS cos it was clearly done at the same time. Unless someone has paid twice? 

Just doesn't make sence to me.

[Tonybandit]

9 hours ago, Corsica13 said:

Hi Tony,

Thanks for sharing your insights.

I'm looking to buy my first 986 S very soon and was wondering how much this kind of job costs as it may be something I need to consider in the near future, specifically clutch + IMS.

Many thanks,

I will message you the price as I'm not sure if I should be putting prices on here. 

If it's OK I will but will wait for admin to OK it.

[Clivescoobydo]

On 11/18/2021 at 3:52 PM, Photogirl said:

I'd be interested in how many of the replacements have failed. Would all the replaced bearings be of a 'reinforced' design and if so does that mean you're largely protected going forward? I've heard of a couple of incidences where a replacement did fail (catastrophically) but I'm not sure of the particulars.

If the existing bearing shows wear chances are the replacement one will too in time. Which is why all should review the removed one. Probably to do with the shaft geometry and a build up of tolerances in the wrong direction. Which would explain the randomness of the failures. 

[mike597]

32 minutes ago, Tonybandit said:

I will message you the price as I'm not sure if I should be putting prices on here. 

If it's OK I will but will wait for admin to OK it.

I'm not a mod but I can't see any issue with sharing the costs involved. 

[Menoporsche]

I thought Revolution publish their prices, so no mystery there?

The only thing, as always here, is how many jobs are done at the same time with the engine out - and how many are found to be needed once it's out (see above re flywheel and clutch).

[edc]

Many Indy's have the price on their website generally around £1200 for clutch and IMS. 

[Tonybandit]

OK so I hope I'm nit over stepping the mark but here goes.

My total was £2401.75.

For that I got the clutch, flywheel, RMS, Duel row bearing (LN ceramic) Cam seal, Clutch seal, Mobil 3000 x1, oil filter, tensioner O ring, Flywheel bolts, Clutch Bolt, stainless bolts for anti roll bar, 2 exhaust clamps + bolts and exhaust gasket.

Job well done if you ask me.

I'm very happy and they will be doing the chains next year as a small amount of deviation was found when running so they suspect the chains and guides. 

 

[½cwt]

@Tonybandit I have posted costs several times, it really is not an issue as long as it is relevant and detailed, as you have done.

Hopefully this work gives you peace in of mind and you can get out and enjoy your investment.

[Tonybandit]

13 minutes ago, ½cwt said:

@Tonybandit I have posted costs several times, it really is not an issue as long as it is relevant and detailed, as you have done.

Hopefully this work gives you peace in of mind and you can get out and enjoy your investment.

Oh I will enjoy the car so much more now.

I'm just so glad I've had it done as it does seam it was a ticking bomb. 

Chains next. 

[mike597]

That seems pretty fair to me. 

[Tonybandit]

On 11/18/2021 at 3:42 PM, Menoporsche said:

There was a phase about 5 years ago where several people replaced their own, or asked the garage to replace it.  Interesting to know if this was such a replacement or the original from way back when.

If the original and it was 20 years old, that suggests that function wasn't much compromised!

One of the reasons that Revolution came up with was that about 5-6 years ago when these cars were at rock bottom pricing, people did things themselves and that is possibly why it was fitted wrong. I've no paper work regarding a new clutch or IMS and the car did come with a lot of paper work.

 

[Little Silver]

Do you get any kind of warning that the bearing is on its way out (rattling noise etc) or does it just go Bang and engine wrecked? I’m a newbie owner of a 1999 986 with 98K miles, a one owner car which has impeccable service history. The clutch feels fine and no slippage so at the moment I’m not inclined to change it.

[Menoporsche]

What we hear is no warning; from hero to zero in five seconds. There have been mutterings about measuring camshaft deviation and the wear in the chain guides, but these seem to be anecdotal. To be honest this is such a rare event it's near impossible to research any consistent warning signals. I've been on BoXa for about 12 years now and think I remember 4 or 5 genuine IMS bearing failures. I think you are right not to change it. 

We have, or had, a sticky about the IMS which included engine numbers so you could even see if yours was one of the weaker bearings. They were introduced around the turn of the millenium (!) so not even sure if your car is at risk.

[½cwt]

1 hour ago, Little Silver said:

Do you get any kind of warning that the bearing is on its way out (rattling noise etc) or does it just go Bang and engine wrecked? I’m a newbie owner of a 1999 986 with 98K miles, a one owner car which has impeccable service history. The clutch feels fine and no slippage so at the moment I’m not inclined to change it.

You car has the earlier double row IMS bearing which is significantly less prone to failure however, like any bearing, it could still fail. A couple of people have spotted oil leaks from the IMS which it you are not very observant could be seen as a rear main seal leak, which is more common, bit as the IMS is immediately above the rear seal it might not be spotted.  A that said, most IMSB failures are without warning and catastrophic.  Hence lots of people have designed ceramic bearing, oil fed bearing and other similar solutions for quite a lot of money. @the baron is at 210k+ miles on an original dual row bearing if that helps put you mind at lest a little.