Knock when shifting 1st to 2nd

[skini]

I read on few threads about knocking under hard acceleration. The problem is most often with engine/gearbox mount (under the battery).
I have got something similar, but i got just ONE knock.

It happens when i accelerate with full throttle in 1st gear(7000rpm), and then i press the clutch, change into 2nd, let go clutch, and then i hear one knock. When i change in 3rd gear, i didn't hear that knock. And when i don't accelerate that hard there is no knock.

So i just wanna know is that famous knocking when changing 1st to 2nd only one knock, like mine, or is it different from mine and i got some other problem?

 

[DrR]

Think they all do, i wouldn't redline it 1st as 172 gearbox's are shite.

 

[skini]

Don't think they are s**t (comparing to some other cars), but can certainly be better.
I don't redline in 1st usually, but i noticed that knock when i did, and i was little worried.

So there are 4 engine/gearbox mounts on 172? Two under the bonnet, one under the car, and one under the battery? Is that right??

Mine gearbox leaks little oil too(not sure where exactly), but as i read here this is something common and not to much to worry about?

 

[TomTom]

Top mount, gearbox mount(under battery), lower engine/gearbox (dogbone) mount and gearbox support mount (between subframe and gearbox)

First mount I'd check is your dogbone mount (underneath) if thats shagged the engine will jolt forwards/backwards and you feel a lot of play in the gearstick.

 

[S22 JGS]

gearbox mounts likely... both mine and a friends had similar issue

 

[Vern]

mine does exactly the same single knock when shifting whilst driving hard..
if i just ignore it will it do the car any harm or is it something that really should get looked at ?

 

[lemonnobby]

Mine does this knock also get a grinding sound as well, but im lasy and havent looked at it yet?

 

[DrR]

How doy you actually tell if a mount is buggered?

 

[TomTom]

Bushes split or even perished rubber, excessive play, you should be able to tell Rollo. Get a screwdriver/prybar on the back of it see how much pressure you need to put on to move it etc.

 

[DrR]

Ok cheers, i'll have a look tomorrow.