I have a 1998 XK8 4.0 with the ZF5HP which, I assume, has a failed A Drum. The car was driving fine, then from a stop wouldn't pull away, then sort of jerks into action. The following day it drove perfectly for a while until I put it into reverse, at which point the non-moving and jerking returned, with a P1722 code. It does move very sluggishly and jerkily, as though the handbrake is on hard.

I'm assuming this is a failure of the A Drum, but was curious that the symptoms come and go - is that to be expected?

 

When mine failed it certainly wasn't intermittent. It went with a BANG! lurch, lights. To call it limp home mode would be generous.

John

 

Low fluid?

 

I believe this is much more likely. Not only "next day it drove perfectly for a while" but intermittent since.

When was fluid+filter changed? Suggest do that asap unless you have documented proof it has been done recently. In any event, up on hoist and check level at recommended temp. Less likely to be a wiring or comms issue, but hey, it has happened . . .

These are far more sensible alternatives to my first take on "What are the symptoms of a Drum failure?" could be that the Guitarists walk off! No? I will go stand in the corner, but hey, if this turns out to be yet another cure from an overdue fluid+filter change, I trust you will forgive me.

Forums are awash with magical cures of 5HP24 and 6HP26 ZFs simply by fluid+filter change and/or correct level fill.

Best wishes,