C3 5 speed gearbox

[Streaky72]

Hi
I have a c3 with a 5 speed borg Warner box conversion I'm told it's the t5 yesterday I got a loud knocking noise in 1st 2nd and 3rd gear but ok in 4th and 5th any advise would be greatly recieved as I know nothing about mechanics

 

[Oneball]

Slightly odd that it’s not doing it in 5th as well as it’s an overdrive and 4th is the direct drive. But I reckon you’ve damaged the lay shaft (counter gear for out American friends)

 

[James Vette]

Photo of your vette?

 

[Streaky72]

Photo of your vette?

Hi
I have a c3 with a 5 speed borg Warner box conversion I'm told it's the t5 yesterday I got a loud knocking noise in 1st 2nd and 3rd gear but ok in 4th and 5th any advise would be greatly recieved as I know nothing about mechanics

Hi
I have a c3 with a 5 speed borg Warner box conversion I'm told it's the t5 yesterday I got a loud knocking noise in 1st 2nd and 3rd gear but ok in 4th and 5th any advise would be greatly recieved as I know nothing about mechanics

 

[Streaky72]

Slightly odd that it’s not doing it in 5th as well as it’s an overdrive and 4th is the direct drive. But I reckon you’ve damaged the lay shaft (counter gear for out American friends)

Update I've had another drive in it today and it is doing it in 5th as well

 

[Oneball]

If it’s doing it in all gears except 4th it’s pretty certain something has gone wrong layshaft wise.

 

[Streaky72]

It sounds like a bit of cardboard on a spinning bike wheel
Layshaft what's the diagnosis for that mate?
Many thanks
Kevin

 

[Oneball]

This is what you box looks like inside. When your in 4th the input shaft is locked to the mainshaft and drive goes straight the way through. In all other gears the input shaft transfers power to the mainshaft via the layshaft.

So if you’ve got a noise in all gears except 4th there has to be a problem with the layshaft.