clutch slip ?

[steve chapman]

Just rebuilt my engine and when i start to move of its fine then slips for a second then bites again , as if i am pulling the clutch in and out quickly, it is fine if i only go very slow , any ideas ? , steve , ps hope this makes sense

[Raveydavey]

Assuming, new plates and correct installation, Either it's the Cable too tight. It shouldn't be tight at all. Wind the adjuster out until the clutch arm is fully back, and try again.

Or it's the spring height / plate thickness combo. Fully compress the clutch with clutch compressor, plates should just separate,(1.5mm gap) not rattle around.

Good article on here http://www.ilambretta.co.uk/clutch.html
?..or the springs are pants.

[coaster]

Not had the problem myself but the front cush drive can give similar symptoms if it the splines aren't engaged under the top hat.

[HxPaul]

Not had the problem myself but the front cush drive can give similar symptoms if it the splines aren't engaged under the top hat.

+1

[Adam_Winstone]

+ lots of times!

[steve chapman]

Thanks for the replys , been out on it again today, seems to be in second gear when it does it , good point about cush drive , because it only slip for a second and then re bites , not sure if its clutch or gears slipping , steve

[Eden]

Sounds like cush to me

[steve chapman]

Thanks guys will have a look

[Adam_Winstone]

You can look for wear on the front sprocket, which might help to identify the issue. As for curing it, you can change the sprocket (some machined too low) and fit a new sprocket assembly spring, however a good check to see if this is the case is to leave everything as it is but to fit a suitable washer under the sprocket assembly to jack it up and to add more preload to the spring. This may or may not put your sprockets out of alignment, which in turn can lead to chain wear, however, it allows you to test it to see if this is the reason for the feeling of clutch slip.

CamLam sell, or did a while back, shims of various thicknesses as they had found incorrectly machined sprockets to be an all too common problem, however, they were good enough to tip me off to the shim that fits between rear sprocket and endplate bearing being the correct size to do the same job. The shim needs to be fitted between the oil thrower washer and the splined column of the front sprocket assembly.

Adam

[steve chapman]

Thanks Adam , its a new front sprocket, but didnt change the other components , could it be that spring isnt as good as it could be , when i built it i was pretty sure that the top hat had seated properly , but looks like this is where the problem is , Steve

[Adam_Winstone]

Yes, springs can go soft. A pal of mine suffered from accidentally fitting a SI spring, which are different; shorter and not as strong.

New sprocket could even be the issue as many are incorrectly machined, allowing the assembly to ride-over / spin.

[steve chapman]

Ordered a full cush drive set , so fingers crossed , once again thanks everyone , Steve

[steve chapman]

So ive bought a full cushdrive set , and a af cassette clutch and its still doing the same bloody thing , £300 down the drain , ive noticed its only doing it in 2nd gear , which i must admit i hadnt noticed, i am now thinking gearbox ? , any help would be great , steve

[Warkton Tornado No.1]

Presumably there’s nothing non-standard about the gearbox?

It occurred to me that if it is a special close ratio gearbox with the cluster comprising pressed on gears as some are, then the interference fit may have failed. The same would occur with the keyed type if the feather key sheared...

Might be clutching @ straws, but it shows I’ve given your problem some serious thought

[steve chapman]

Italian gp200 box new sliding dog , didnt change gear selector spring or ball bearings , thanks for your reply though

[dickie]

Second loose gear wrong way round and not catching sliding dog properly?

[steve chapman]

If the second gear was in wrong would it give that feeling ?

[Warkton Tornado No.1]

Post by steve chapman » Thu Jul 14, 2016 10:00 pm

If the second gear was in wrong would it give that feeling ?

Ha! Never tried it! But it wouldn’t hold second gear as the dogs would be misaligned...

[Adam_Winstone]

Sorry to hear that you're still struggling with this one but at least you've ruled a few things out, which is what problem solving is all about.

I only suggested that you tried a 50p shim to preload the front sprocket assembly and test to see if that was the cause, not spend £300 on parts

Good luck getting it sorted.

Adam

[steve chapman]

Not blaming anyone Adam , just trying to solve it , its doing my head in ,steve