Torque converter clunk

[daviesbike]

Hi every one,

I am getting asked this quite often by customers 4.2 TDI owners and S8 owners who are saying when they come off the throttle and are just coasting as soon as they press the Throttle pedal they feel a clunk like the gear box is not engaged fully and there is almost like slack in the transmission.

After several D3 owners coming to me for a full gearbox service including rear diff oil, this dose seem to make it much less aggressive but dose not eliminate the problem all together.

Also After doing 4 lots of diff oil it shocking at how disgusting and burned it looks after just 60k

I am wandering if anyone else suffers with this and if there are any known solutions to the problem ?

[snapdragon]

Yes, on my 3.0TDI such as when lights turn green when approaching, especially downhill - I have sort of learned to drive round it by breathing on the throttle (so it is just off the 0% switch) and leaving it there for a second before pressing a bit more..

[daviesbike]

what causes this ? is it a bad torque converter ... or worn clutches .. or simply a software thing ?

[Mechcanico Lee]

I have felt this in my 4.2 tdi ....like you say in your first post like transmission slack ....perhaps part of the feeling is just that , it has a long driveline ....

autobox , front diff, front shafts, rear transfer box , prop , rear diff ...its got a lot to turn , but i reckon some of it could be cured with software changes and how the valve block bleeds over .

The S type and xj jags with the zf boxes i work on can have that 'slop' feel with them, with Autologic a software flash reduces this feel greatly ....its like you have fitted a whole new box ....makes them have a sharper response but still with smooth change over and minimum flare up between gears

[daviesbike]

Are you and auto box mechanic ? .. I'm looking for someone to map my box with the engine ..

[Mechcanico Lee]

Not a auto box specialist as such, been a tech for 27 years and work on models all types of repairs , ideally your looking for a mapping specialist .....how about Revo or Torx Tronics

[a25c]

I am currently dealing with this exact problem and wondering has anybody any update on this problem?