Gearbox not engaging

[Jamesk]

Hi, I recently replaced the gearbox oil and now when I accelerate the car just revs up (in any gear) before slowly engaging. If I slowly accelerate the gears eventually fully engage and then Within that gear i can accelerate hard. The car is a manual series 2 Roadster. Thanks

[christopher storey]

Oh dear, that sounds horribly like a slipping clutch . Is it possible that you have overfilled it ( it takes about 2.75 pints IIRC) ?

[john wyatt]

Sounds like clutch is holding on, maybe something suspect with the clutch hydraulics.

[Jamesk]

Thanks for the replys, I've Jacked the car up - and looked at the slave cylinder and everything seem fine there ( I replaced this a couple of years ago). There does seem to be oil all over the gearbox which has spilt onto the exhaust. This wasnt there when i replaced the oil and this whole problem only started when I replaced the oil. I used Halfords Gear Oil EP 75W/90 GL-5 - Is this correct? Perhaps the oil is too thin has leaked out onto the clutch plates causing it now to slip? Thanks

[john wyatt]

The fact that the slave or master clutch cylinder look OK does not really mean they are OK, if it were a contaminated clutch i would expect it to slip when you accelerate hard and you say it is OK, best way to check if clutch is slipping is to find a hill and engage a higher gear than you maybe would normally if the revs are picking up quicker than the cars speed then your explanation sounds possible/likely, the hose could be collapsing also and acting like a one way valve, your hydraulic foot pressure can push it "on" but the spring action of the clutch is not enough to return it fast enough, does seem odd it has happened when you done the gearbox oil though!

[christopher storey]

Nothing wrong with that grade of oil, but the leakage does suggest overfilling. It is 2.75 PINTS not litres