Thread: Knocking sound from the transmission

Knackered engine or transmission mount?

As it only occurs when adding power it could be one of the engine mounts but I have not come across this in a Puma. The heat shield on the turbo can rattle when the bolts loosen.
Cannot see it being an engine internal issue. If you have access to a ramp it would be easy but time consuming to just get a small pry bar and see if any thing is loose.
A very worn shop absorber bushing could be at fault but there are a lot of other bushing you could check when it is on the ramp.
When the PCJ fault was an issue this led to a rattle in the engine but you are well out of that batch.

Thanks Guys

I hadn't even thought about mounts. I'll check them. I'm pretty sure it's not anything in the suspension or under the bonnet it's too central and to the rear of the transmission.

Cheers

Steve

Have a look in the seat boxes under the front seats. If (like me) you store stuff there it could be moving. Hopefully it will be something simple.

Check the rear suspension ball joint on top of the diff.

in a defender, where would you start the list of things to check. Obvious that come to mind:

1) drive flange flogged out;
2) A frame ball joint or upper control arm chassis end bushes;
3) engine and transfer case mounts;
4) intermediate shaft between box and transfer if it's the original spud shaft and was assembled when lub was in short supply;
5) front radius arm bushes or bolts being tight. on mine a shagg radius arm bush transmits the noise through to the chassis under the drivers seat which is adjacent to the transfer case;
6) while you are under the front diff, check panhard bushes. That can be a noise but more often is associated with steering symptoms too.

knocking on power on / power off sounds like either the ball joint above the rear diff.
Or rear diff itself which is by far way more common than the ball joint on a Defender TDCi (2007 - 2016).

BUT they are quite a clunk clunk driveline on that model, so as others have said it can be clutch, adaptor shaft, transfer case centre diff, rear diff.
a clunk on this model is a very broad statement.

Should also point out that a dragging handbrake will result in any slack being more prominent.