ZF trans makes grunting noise as if I'm backing over something. Forward seems to lock up until I give it more throttle.

 

What year XK do you have - 2 different transmissions available


Are these symptoms there all the time or do they go away after cycling the ignition?

 

TNX. 2000XK8 I think it's a ZF5

 

I'm gonna try and guess what you mean-

1. When you back up it struggles to engage, but moves
2. When you go forward, it doesn't engage until the revs come up, but then goes

Correct? If yes, classic A-drum.

 

Sorry, the problem just started. It happens every time I start the car.

 

dsnyder, that's close. Good guess. U think it's the A drum?

 

From what you describe I would agree with dsnyder - but when this problem started, did you put it into gear, then as you press accelerator it revs up then bangs into gear? This is what usually happens with the drum breaks.... "might" still be something else.... Torque converters have given issues in the 5HP24 as well.


Do you have any warning lights on the dash?

 

Yes. Don't drive to avoid causing more damage.