Clutch and/or gearbox replacement

[David Taylor]

HI there. Yesterday the clutch went on my 99,000 mile Spitfire MKIV. The car was restored back in 1990/91 and the clutch was replaced then so I guess it's done well to last 30-odd years.

My question is this - as I will have to have the clutch replaced, is it worth getting the gearbox replaced at the same time? It was working fine and the overdrive unit was too. But I'm guessing that as it reaches the 100,000 mile mark, the likelihood that it may fail in the next few years.

Or should I adhere to the maxim, 'if it ain't broke, don't fix it'?

Thanks in advance

David

[johny]

just one thing first. When you say the clutch has gone what are the symptoms?

[David Taylor]

It has been harder and harder to find first and reverse gear. Then on my way down to Brighton yesterday I couldn't get into any gear and the gearbox was making a horrid noise. The clutch cable is fine, as is the reservoir on the clutch cylinder. Also, when the engine is off, I can easily go through the gears. So I am pretty certain it's the clutch.

[Steve P]

I would say for the gearbox, sounds ok if the gears can be selected when the engine is off,has it had regular oil changes or is it noisy?.

Clutch would have done well to last 100k miles,my Vitesse only lasted 15K.Pretty straight forward swap.Check the hydraulics at the same time.

S

[David Taylor]

2 minutes ago, Steve P said:

I would say for the gearbox, sounds ok if the gears can be selected when the engine is off,has it had regular oil changes or is it noisy?.

Clutch would have done well to last 100k miles,my Vitesse only lasted 15K.Pretty straight forward swap.Check the hydraulics at the same time.

S

Everything was fine til yesterday and the car is regularly serviced. Sounds like I should just go for a change of clutch.

[johny]

Does the pedal feel any different to operate now? The normal failure of a high mileage clutch is that it starts to slip when accelerating because the friction material is worn but it doesnt sound like this is the case with yours. Therefore I think its much more likely theres a problem with the hydraulic side or/and the actuator mechanism than the clutch itself. Unfortunately theres not many checks you can do to confirm this without removing the gearbox cover...

[David Taylor]

7 minutes ago, johny said:

Does the pedal feel any different to operate now? The normal failure of a high mileage clutch is that it starts to slip when accelerating because the friction material is worn but it doesnt sound like this is the case with yours. Therefore I think its much more likely theres a problem with the hydraulic side or/and the actuator mechanism than the clutch itself. Unfortunately theres not many checks you can do to confirm this without removing the gearbox cover...

I use a brilliant garage in East Sussex who I am sure will be able to diagnose whether it's the clutch or the hydraulic side.

[johny]

One possibility for example is that the master cylinder is failing. This has a seal in it that if leaking stops fluid being sent to the slave cylinder that operates the clutch instead allowing the fluid to go back into the reservoir. If this happens with the brakes its easy to detect as the pedal goes to the floor but with the clutch its obviously more difficult - however you might see the fluid level rise in the reservoir as you press the pedal...

[Pete Lewis]

if you can engage gears engine off but not engine idling it is the hydraulics and  actuation thats in trouble 

nothing to do with  clutch unit     i would get this checked out as a first step

then there is the possibility the withdrawl pivot pin has fallen out   very common 

Pete

[Unkel Kunkel]

Before even considering replacing anything  - overhaul your clutch hydraulics.