sadly my optimism above was proved wrong. Replacing the solenoid made no difference. The fault was indeed the reverse band. I booked in with a local auto transmission specialist and they confirmed this is a common fault, due to the lugs breaking off. All fixed now but approx £1k cost.

Finally got around to working on this. I have removed the low clutch timing solenoid valve and tests show that it is not working. Going to order one and fit next weekend. £40 fix will be a great result 😀

If it does turn out to be the reverse brake band (I suspect it is). Is that a job that only an expert/specialist should attempt? I'd like to have a go myself if possible but can't seem to find any guidance online for the task at hand.

Cheers for tips on checking fluid level, I'll try that at the weekend but I fear the problem may be as Defunct says; a broken band. The car is a 2003 and on 155k miles so had a good innings. It may be some time before I get on to this as my wife is about to have a baby so money and time are...

Thanks, will check oil level and quality. I'm certain the 'clunk' is normal as it's always done it and I might not be describing it very well.

Hi, I recently got one of those "the cars not working" calls from the wife where she tried to tell me the car wouldn't reverse. I suspected something stupid on her part like the time she couldn't start it whilst drive was selected. This time though it turns out she's right. The car drives...