Mcleod Rst clutch slipping

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DEVONMAN
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Post by DEVONMAN »

Is the second plate in the same condition and is the gearbox shaft damaged?
It's possible you had a mismatch of plate splines as there are 2 types of 23 splines plates. One type (Imperial) suits the Rover LT77 and the second type (Metric) fits a Ford Cosworth gearbox. They are both swopable but have slightly different angles to the splines.

The twin plate clutches have much less bearing area at the splines and a mismatch of splines would have more chance of exceeding the permissable bearing stress on the splines. Of course there is a possibility that the hub had not been heat treated properly.

Also, if the clutch is not initially set up properly, then one of the plates may do more of it's fair share of the work at take off.

The warped plate may be due heat resulting from the slipping you experienced previously.

Regards

Denis


1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


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Discopotatoes
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Post by Discopotatoes »

DEVONMAN wrote:Is the second plate in the same condition and is the gearbox shaft damaged?
It's possible you had a mismatch of plate splines as there are 2 types of 23 splines plates. One type (Imperial) suits the Rover LT77 and the second type (Metric) fits a Ford Cosworth gearbox. They are both swopable but have slightly different angles to the splines.

The twin plate clutches have much less bearing area at the splines and a mismatch of splines would have more chance of exceeding the permissable bearing stress on the splines. Of course there is a possibility that the hub had not been heat treated properly.

Also, if the clutch is not initially set up properly, then one of the plates may do more of it's fair share of the work at take off.

The warped plate may be due heat resulting from the slipping you experienced previously.

Regards

Denis
I think your right about the mismatched plates, as one looks untouched, luckily no visible damage to the input shaft
stevieturbo
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Post by stevieturbo »

So do both the discs actually sit properly on the splines ?

Can you post a photo of the input shaft to see exactly where the two discs have been sitting ?
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sidecar
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Post by sidecar »

I can see how that happened (or guess at least!)

I've worked on a couple of non-standard Rover block to non-Rover gearbox setups and found out that you can have real problems with lack of spline engagement if you just bung the gearbox and bellhousing on the back of the Rover block.

My setup uses a JE bellhousing and T5 box, if I had used a standard Borg and Beck clutch plate I would have had only 10mm of engagement, as it happened I used a Helix friction plate and that has an offset central boss that is 10mm deeper than the standard boss, this gave me 20mm engagement. I still was not 'over the moon' with this so I had 9mm machined off the back of the bellhousing, this got my engagement up to 29mm.

The second setup I've looked at is more worrying, it was a TVR bellhousing meant for a Rv8 and T5 box. The standard clutch plate from memory would have had less than 10mm engagement, the Helix plate pushed this up to around 15mm. The back of the belllhousing and the front were machined in order to get the figure up to around 20-22mm. (We could not machine any more off the bellhousing for fear of making it too weak)

Your pictures will make Muscle Manta pleased that he got the machining done. (His engine is the Rover TVR combo)
Discopotatoes
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Post by Discopotatoes »

stevieturbo wrote:So do both the discs actually sit properly on the splines ?

Can you post a photo of the input shaft to see exactly where the two discs have been sitting ?
I'm away from the car till next week but the discs were sitting in the middle of the input shaft and properly located, ie the were well away from the end bit that chamfers down for the spigot bearing
stevieturbo
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Post by stevieturbo »

Discopotatoes wrote:
stevieturbo wrote:So do both the discs actually sit properly on the splines ?

Can you post a photo of the input shaft to see exactly where the two discs have been sitting ?
I'm away from the car till next week but the discs were sitting in the middle of the input shaft and properly located, ie the were well away from the end bit that chamfers down for the spigot bearing
Which disc was it that has that spline ? flywheel disc or gearbox disc ?

It is more likely to fall off the splines at the latter, than the flywheel side.

So do both discs slip onto the splines and feel fairly secure ?

Did you carry out all checks mentioned before about installation, and ensuring release bearing isnt pressing the fingers etc ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0
Discopotatoes
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Post by Discopotatoes »

stevieturbo wrote:
Discopotatoes wrote:
stevieturbo wrote:So do both the discs actually sit properly on the splines ?

Can you post a photo of the input shaft to see exactly where the two discs have been sitting ?
I'm away from the car till next week but the discs were sitting in the middle of the input shaft and properly located, ie the were well away from the end bit that chamfers down for the spigot bearing
Which disc was it that has that spline ? flywheel disc or gearbox disc ?

It is more likely to fall off the splines at the latter, than the flywheel side.

So do both discs slip onto the splines and feel fairly secure ?

Did you carry out all checks mentioned before about installation, and ensuring release bearing isnt pressing the fingers etc ?
The damaged disk was nearest the flywheel,
All the checks were carried out on installation,
As for the disks slipping on and and feeling secure one does the other is to far gone, I will try and get the misses to take a pic of the input shaft you can see where the discs were sitting
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