R8 Alpine clutch shudder

Always interesting on here.....

For what it is worth, here's a poor photo of a bog standard R8 clutch cable in place with normal droop. It's been like this forever and has no clutch shudder. My gearbox isn't as amazingly clean as BobG's but it has not been out of the car for at least 35-40 years and 200,000 km. :)

Another answer for BobG - the cable outer is not secured at the gearbox end, it just pulls out of the adjuster assembly. It's held in by the greater length of the outer relative to the distance from the fixed mounting point at the front and of course by the inner cable being secured to the clutch fork. So the engine/gearbox assembly can certainly move quite a bit on the rubber mounts without changing the clutch cable adjustment and, therefore, without causing shudder (not that there is not necessarily another contributing factor like the clutch itself). The easiest thing to play with is that cable droop with a spacer arrangement where it goes into the adjuster (which will then need adjusting of course). I have 2-3 mm free play.

I certainly make sure the two steel strengthening braces are in place and tight. Over-engineered for freeways perhaps but they were designed and built when many people drove on bad roads. There are several different geometries for the different engine versions. Heaven knows why as they are all Sierra engines, but the block mounting points changed over time.

I make sure all the cooling stuff is in place, and the car certainly is prone to over-cooling! Very efficient system and patented by Renault I think. I've never run it any other way but some obviously don't have problems without all the trays in place. Mine does get driven on 40-degree days sometimes.... It never overheats.
You mention using a spacer to provide enough droop. I was wondering how to get more slack (droop) when the cable has a fixed length. A spacer makes sense. I'll see how my new cable fits and if I need to fabricate a spacer.

As to the gearbox braces, neither my R8 or R10 parts car had them. The R8 was from a stalled restoration project so it might have had them originally. I noticed my non-factory manual lists several versions of the 330 gearbox, some of which were designated "rough road." My R10 didn't have one of these. Maybe only cars with these gearboxes had the braces.
Bob
 
No BobG, read post number 37. All cars with 330 gearboxes had side braces and a light cross brace across the bell housing. But if you don't want to put them on don't it is your choice.
 
No BobG, read post number 37. All cars with 330 gearboxes had side braces and a light cross brace across the bell housing. But if you don't want to put them on don't it is your choice.
I'd forgotten the "light cross brace" you know. I don't think I've had that for a very long time.
 
Me? I'm driving Miss Daisy and none of my cars have the side braces and never had. I'm not saying what is right and what is wrong but I think it is a "belts and braces" story.

Frans.
 
I reckon KB (renault8&10 ) never drove it hard enough for long enough to encounter overheating. I'm not sure if he was watching the gauge at Marulan when he ran there last.:unsure:
 
I guess my question is.... why did Renault go to the cost and trouble of fitting these things if they weren't required? If they were trying to be price competitive why spend the extra money? It is a bit like removing the brake balance valve from the rear. I have a mate (a mechanical engineer) that has spent most of his career driving prototype Jaguars and Landrovers around Europe and various race tracks and recommending changes to improve the vehicle prior to production. He is currently fitting a rear brake balance valve to his standard Nissan Skyline to improve braking performance some thing he claims should have been fitted in the first place. Vehicle manufacturers do not spend money on vehicles if it is not necessary.
The brake balance valve, I think that on a standard R8 or R10 car with standard ride heights and obviously higher Center of Gravity, the see-saw effect is much bigger. If a complete non-petrol head guy or lady, in those days, slammed on the brakes to avoid contact with something, the "dive" effect and weight transfer would be much bigger. The nose will dip lower and the tail will lift higher. That will cause the rears to lock and control will be lost. With most of us being hoons, the suspension is lowered and the car will remain more parallel with the road allowing the rear brakes to work more and not loose traction, so it is "okay" to remove the balance valve/regulator.

When I fitted a second master cylinder and balance bar to the race car I set it up to a 60/40 balance. I still need to meet the guy that can out-brake me, wet or dry. The 60/40 balance was achieved by taking the temperatures of the rotors as references. Front engine front wheel drive cars have their brake balances around 80/20 to prevent lock-up.

Regards, Frans.
 
I reckon KB (renault8&10 ) never drove it hard enough for long enough to encounter overheating. I'm not sure if he was watching the gauge at Marulan when he ran there last.:unsure:
I normally used the throttle like a light switch. That car actually did quite a few long trips. - Southern highlands several times, Canberra a couple of times and Cowra to name a few.
 
Agree with Frans on removal of the standard brake balance valve on a modified R8/10. The modifications mentioned by Frans improve the performance to a point where the balance valve is a big disadvantage to the level of braking needed on a competition car. It is a whole other world to a standard R8/10brake balance. The valve actually makes it dangerous.

I have no trouble outbraking and passing ABS equipped Miganes and Clios on a racetrack with a well sorted and balanced system without a rear valve. If I replaced the balance valve the brakes would not be in balance, wet or dry track.
 
You mention using a spacer to provide enough droop. I was wondering how to get more slack (droop) when the cable has a fixed length. A spacer makes sense. I'll see how my new cable fits and if I need to fabricate a spacer.

As to the gearbox braces, neither my R8 or R10 parts car had them. The R8 was from a stalled restoration project so it might have had them originally. I noticed my non-factory manual lists several versions of the 330 gearbox, some of which were designated "rough road." My R10 didn't have one of these. Maybe only cars with these gearboxes had the braces.
Bob
Hi Bob :)
When you fit your new cable the spacer can go at the front end too. No need for a fancy sleeve in the rear hole. All it needs is for the outer to be too long for the distance between the two holding points by a reasonable amount so it does have to form a 'bow' or droop.
Back in the good ol'days we reused the outer and made up inners out of stainless boat rigging cable and fittings. They will make them up in the shop for you. Just recently I did one for a not so old, 2003, Jap car that was no longer made. Molly grease the cable well before use.
Jaahn
 
The new clutch cable is installed. The droop is formidable! And no more clutch shudder! Thanks all for the advice and education.
IMG_0470small.JPG
 
Droop is always like that and people will continue to tell you you have some thing dragging low on your car, I just thank them and say that is how it is.
 
I have tied mine up and I think it is to the speedo cable. So the droop is horizontal and not obvious.

Frans.
 
I have tied mine up and I think it is to the speedo cable. So the droop is horizontal and not obvious.

Frans.
Funny, when I saw his photo, with more droop than mine, I was thinking of a weak baby coil spring to pull it gently sideways.

Nice new tyres Frans!

Cheers
 
Funny, when I saw his photo, with more droop than mine, I was thinking of a weak baby coil spring to pull it gently sideways.
Nice new tyres Frans!
Cheers
You guys never heard of zip ties ;) The wonder item of the decade !!
Jaahn
 
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