Clutch problem - clunking noise when coming on/off throttle

[tordep]

Hi everyone, having some problems with my 2012 academy, car has done 1900miles and I am having it services in dartford later this week for the 1000miles check.
Since I bought it 3 weeks ago it had a small weep, couple of drops when left overnight from the bottom of the gearbox, I know its gearbox oil as it is fairly clear as opposed to the engine oil, its also thick and smells awful.

It also has had since I bought it a crunchy 2 when cold and a clunking noise that seems to be coming of the main drive shaft/gearbox/gear lever area when coming on/off throttle, or releasing the clutch less smoothly. I can't make it do the noise if I make sudden turns so am pretty sure its not the gearbox hitting the chassis, seems to come from "inside" somehow, only think I know is:

Gets worse when gear box oil is warmer.
Has been getting worse since I got the car (only had 1300miles).
Apart from crunchy 2 all shifts are smooth when gearbox up to temperature and reverse goes in without a problem too.

Anyone has any idea of what this might be? Is it worth having caterham check it or take the car some place else to have it checked, somewhere around m3 ideal?

Any help greatly appreciated, its dampening my enjoyment of the car considerably, can only manage a half grin after each drive.

Thanks

Pedro
2012 academy - 1.6 sigma

its not the This

[DCL]

If its only 2nd gear and ex academy then, at a guess, it's a synchromesh issue. You could try Redline MTL (if not already in it) which can restore synchromesh operation and improve gear changes. But ultimately an rebuild is the only sure way of identifying and resolving it properly.

[tordep]

Thanks, the crunchy gear change is only in 2 and only when its cold, all other gears are fine, the clunk when going on/off throttle or when I release the clutch too quickly happens in all gears, from cold and when its hot. It sounds like the transmission shaft is loose, although these noises are difficult to pin point. I will see if caterham can diagnose it, any ideas on a rebuild cost? and a good place to do it.

To be honest I am more worried about the clunk than the crunchy gear change into second.

[radical78]

get it on a ramp check gbox mounts diff mounts and propshaft ujs and drive shaft joints if they are all ok its box out

[tordep]

Just managed to get under the car and removed also the tunnel cover to see the box from above and there seems to be contact between the gearbox and the chassis (drivers side), I think alignment of the clearances can only be done with an engine hoist so I cant see a way around that at the moment. Still there is a leak coming from somewhere I might have a poke underneath to see if something is obviously wrong.

Thanks for the help.

[tordep]

Right, some success, the chassis support at the end of the gearbox (the two screws that attach to the chassis) can be moved and with some persuasion moved to allow the right clearance, even with the engine mounts still in place and fastened, so that should be good, the leak however seems to be coming from the joint between the bell housing and the gearbox so its a job for when I have the flywheel done.

The oil that leaked seems to help the chassis mounting points to shift as its is pretty oily down there.

Thanks for the pointers, I just need to get the right oil to make sure the gearbox doesnt run out of oil.

[StEVEN7]

Hi I own a 1.6 Sigma Supersport the clonking noise you describe could be the drop links on the rear ARB they are poor quality and can they can clink when pulling away in any gear.....check the oil leak isn't coming from the rear gearbox seal if you have a 5 speed i...Oil can run down the under centre line of the gearbox and drip down between bell housing and main box.....
Sometimes noises can come from different locations to where you think they are I had a whining noise which I thought was the diff but was the rear seal as described above... Hope that helps StEVEN Eastkent L7Club AR

[tordep]

Thanks it does help, will check the seal and the rear arb, if I have one, not sure the academy's have one, if I do it might be an excuse for powerflex bushes.

[ninelevent]

Hi

I have the same issue after a rover k upgrade on crossflow chassis .( engine mount home made !)

Noise like a propshaft not balanced or a diff dead or without oil but very hard to find .

Clunk is the same with the old 5 speed and the recent 6 speed gearbox .

If you have found the problem , let me know .

Will check tomorow with a lift !



I

[ninelevent]

Hi

I have the same issue after a rover k upgrade on crossflow chassis .( engine mount home made !)

Noise like a propshaft not balanced or a diff dead or without oil but very hard to find .

Clunk is the same with the old 5 speed and the recent 6 speed gearbox .

If you have found the problem , let me know .

Will check tomorow with a lift !



I

[tordep]

I did yes, it was a broken diff mount, caterham upgraded it for free to the new version I think its a recall item on my 12 academy.