8 replies to this topic

[merther]

I’ve recently fitted a new engine. I’ve used the same gearbox as last time as it was all fine. No crunching and went through the gears nicely. When I built the engine I didn’t touch the gearbox as it was all ok when in the car.

After fitting the new engine I’m now struggling to get into 2nd gear when downshifting from 3rd. It crunches at higher speed. The car is a mk1 and I have made a bracket to hold the Rod change linkage into a mk1 round tunnel. The previous engine has this and I had no problems.

I have tried to move the bracket to find the fault and create different angles, but no luck. However, I angled the Rod change shifter so it was lower on one side, just to see what it would do. This made the crunching worse, even at a low speed, it would crunch from 3rd to 2nd. So I positioned the linkage to angle straight again and now the 2nd gear will go in…no crunching…but at more higher speeds, it still crunches. 
also, I’ve sat with the car stationary and revved the engine to around 3k rpm and gone down from 3rd to 2nd and no crunch…..

when the engine is switched off and the car stationary, it is sometimes difficult to get the gears, almost like something is stopping it going in. Almost like it is hitting something. If I try it again, it goes in ok. I’ve used molegrips on the linkage and tried to engage gears with that instead of the gearstick and it didn’t put up any resistance and no problems going through the gears. 
any ideas what this could be? If it was the synchro in 2nd gear  it would crunch when I revved the car up and shifted down from 3rd to 2nd while the car was stationary?

any help appreciated. Thanks.
 

[Spider]

I'm inclined to think this maybe a clutch issue.

[nicklouse]

The angle and position of the bars is not really that important. There have been many home made kits to position the gear leaver in other locations and a few factory ones.

 

as above or your gearbox did have issues that have only just become evident with the rebuild.

[merther]

I'm inclined to think this maybe a clutch issue.

Hi Spider, yes quite possibly I’m just confused why the situation would improve when I tilt the Rod change ?

 

im also using cheap 20/50 oil as the engine is running in, could this cause a crunch? I have always used valvoline vr1 which I will be using again after the engine has been run in.

Edited by merther, 23 May 2025 - 08:37 AM.

[Spider]

Hi Spider, yes quite possibly I’m just confused why the situation would improve when I tilt the Rod change ?

 

im also using cheap 20/50 oil as the engine is running in, could this cause a crunch? I have always used valvoline vr1 which I will be using again after the engine has been run in.

 

 

I can't see how the shifter would cause this.

Usually with running in oils, the shifts are better, unless the oil is friction modified, in which case, it's not only undesirable for the gearbox, but it won't let your engine run in either.

When I say 'clutch' that's all parts of the clutch system, including the Primary Gear.
 

[merther]

 

Hi Spider, yes quite possibly I’m just confused why the situation would improve when I tilt the Rod change ?

 

im also using cheap 20/50 oil as the engine is running in, could this cause a crunch? I have always used valvoline vr1 which I will be using again after the engine has been run in.

 

 

I can't see how the shifter would cause this.

Usually with running in oils, the shifts are better, unless the oil is friction modified, in which case, it's not only undesirable for the gearbox, but it won't let your engine run in either.

When I say 'clutch' that's all parts of the clutch system, including the Primary Gear.
 

 

ok thanks for your help, when you say primary gear, what could be wrong with that?

[Spider]

ok thanks for your help, when you say primary gear, what could be wrong with that?

 

It's not free spinning. There can be a number if causes for this, but rather than play 20 guesses, perhaps diagnose it.

What type of clutch is fitted ?
 

[merther]

 

ok thanks for your help, when you say primary gear, what could be wrong with that?

 

It's not free spinning. There can be a number if causes for this, but rather than play 20 guesses, perhaps diagnose it.

What type of clutch is fitted ?
 

 

thanks. I’ve discovered my slave cylinder is leaking slightly. Clutch fluid has run down and burnt the paint off my wok. Guessing this could cause the issue!? Although all other gears are fine…so not sure. I’m going to replace.

clutch is med pre vertigo with lightened flywheel. Bought as a balanced kit.

ive always had a very low biting point. I’ve replaced everything so it’s all new but can’t get the bite pint higher up. The obly thing I’ve never replaced Is the master cylinder but it seems all ok.

[Spider]

thanks. I’ve discovered my slave cylinder is leaking slightly. Clutch fluid has run down and burnt the paint off my wok. Guessing this could cause the issue!? Although all other gears are fine…so not sure. I’m going to replace.

 

See where it's at once you've replaced the slave, they don't need to 'loose' much to give grief.