Clutch failure again!

[jeff_hooper]

1996 V8 - with revised Twin Plate clutch fitted at factory in 1998. And the twin plate clutch replaced in 2003 at 27K. Mileage now is at 34K.

In the past 50 miles I'd experienced a couple of crunched gear changes, when accelerating hard and doing quick upchanges. I just though I'd rushed things, been a bit too agressive and not had the clutch pedal down properly.

Tonight things have developed further... First a couple more crunched changes and a feeling of it being hard to engage the next upchange gear (ie. 3 to 4). Then a VERY worrying noise when setting off in 1st gear, just the first 20% or so of take up then all felt/sounded normal. The noise sounded like a fast spinning spline trying to engage (with difficulty) against it partner. Later (on the motorway) the clutch was definately slipping in the upper gears on full power.

Now my mate had the car before me and at 27k he left my house late one night in 2003, and on his drive home ended up with what sounds like an identical problem and a clutch replacement was needed to fix it... Interestingly, I have the old clutch from that 2003 replacement, its in front of me now, the central spline on what is described in the Lotus manual as 'Friction Plate 1' (nearest flywheel, furthest from gear box) has its teeth worn away (Friction plate 2 - has sharp clearly defined teeth).

Initial evidence suggests I'm going to find the same wear/problem when I pull the box and inspect the clutch and that's after only 7,000 miles. So Forum readers any guesses/suggestions?? as to the problem??

My past record with cars suggests I'm have reasonable mechanically sympathetic and I know my mate (the previous owner) isn't a nutter and isn't hard on cars... so any suggestions as to what's up. My thoughts are a misalignment problem between engine/gear box, causing accelerated clutch wear...

I also wonder if a Derek Bell gearbox job would be a worthwhile investment.... It might solve a possible missalignment problem that will save me another

Edited August 23, 2006 by jeff_hooper

[Jonathan]

Might simply need adjusting on the clutch side of things - perhaps the fork is not traveling far enough ?

Best to check the simple things 1st before rushing head on into a Derek Bell upgrade - besides that (if I have my memory on straight) only stengthens the shafts, it does nothing for the gear change.

Sounds like there's an issue shifting, which tends to be either the clutch isn't dis engaging propperly and the box is having trouble synchonising or the syncros them selves. Have you tried double clutching to see if that helps ?

Either which way if you have a slipping clutch (as Travis will kick me in the head if I don't mention it !) the best thing to do is get it sorted asap or check the adjustment - thing is it might need adjusting and changing as any misadjustment might cause it to wear un-evenly as you describe.

[Zhastaph]

Interestingly, I have the old clutch from that 2003 replacement, its in front of me now, the central spline on what is described in the Lotus manual as 'Friction Plate 1' (nearest flywheel, furthest from gear box) has its teeth worn away (Friction plate 2 - has sharp clearly defined teeth).

With regards to this there is a very definate manafacturing problem on at least some of the v8's in that the spline on the input shaft is not long enough to go all the way through the 2nd clutch plate.

All is fine until 1 day you dump the clutch letting the wheels spin in first at which point the bit of the teeth that are engaged with the spline get torn out.

The result of this is then that the clutch plate wont slide correctly up and down the spline generally resulting in the clutch dragging causing crunched gears.

[williamives]

I also wonder if a Derek Bell gearbox job would be a worthwhile investment.... It might solve a possible missalignment problem that will save me another

[jeff_hooper]

With regards to this there is a very definate manafacturing problem on at least some of the v8's in that the spline on the input shaft is not long enough to go all the way through the 2nd clutch plate.

All is fine until 1 day you dump the clutch letting the wheels spin in first at which point the bit of the teeth that are engaged with the spline get torn out.

The result of this is then that the clutch plate wont slide correctly up and down the spline generally resulting in the clutch dragging causing crunched gears.

Hmm. that's an interesting comment. I have the past clutch assembly which was changed 7k back (Under the previous owner and I know it failed withe the same symptoms mine has). The clutch plate that is nearest the flywheel/engine and at the end of the gear box shaft is completely stripped of spline teeth, the inner plate has 'deformed teeth' almost like a push bike chainwheel that has done too many miles.... From the noises I've have heard I guessing I'm gonna find the same as the previous clutch...

Now my V8 is a 96', as such an early V8 and originally run by a Director at LOTUS, fitted with the single plate clutch and later retro fitted by LOTUS to the Twin plate clutch... I wonder if they have modified the gearbox input shaft length for the late Twin plate clutch but just 'made do' with the original V8 box spec for pre 98' cars that were retro fitted with the twin plate clutch and they didn't replace the boxes with the later specs when they made the recall?

I love to know if anyone has any ideas or information or specs on this idea?

I'm gonna pull the box off in the next few days and have a look. My current thinking is, I can't see the point in putting a new clutch on ever 7,000 miles at

Edited August 25, 2006 by jeff_hooper

[jeff_hooper]

I've now got the box off and it has failed in the same way as the previous clutch 7,000mls back. The spline on one clutch plate is none existant the other badly chewed.

As you can see from the picture the drive spline going into the gearbox is also beyond further use which means I am looking to get a Derek Bell gearbox conversion/rebuild.

Jeff