clunk going into gear

1999 p38 auto just changed oil in gearbox and engine. Putting into reverse first time starting make a nasty clunk. Didn't do it before. Followed the instructions about fill the sump then run the engine and move though the gears and continue to fill with the engine running until there is oil coming out of the filler hole. Anyone give me a clue?

if you have no wear in the rest of the drive train which presumably you dont as its just occurred ,atf is very detergent and can clean lacquer off valves etc leading to issues such as yours ,what was oil like you drained out , and is also a good reason not to change oil quite quckly or flush it to change whats left in torque convertor

Hi James, Thanks for coming back to me. The oil I drained out was red but slightly dirty. The oil I put in was new ATF Dextron 111 plus a litre of Lucas gearbox fix (Datatec's Snake Oil) If you mean I put the new oil in too quickly, then I suppose that is a possibility as I was sort of panicking to get it filled. I dont suppose it really needed changing but as I had decided to try this Lucas oil, which I did not see as it would do any harm and might help with what I felt are late changes (3rd to top) I felt I might as well change to oil at the same time.

no ,when you change oil you can only change some of it (whats held in sump )some like to do a couple of changes to try and change it all ,it may well get better after a few hundred miles

Thanks James, we are about to do a trip to Luton, about 160 miles, towing a caravan
It only seems to do this going into reverse after standing for a period of time (oil settled?)

Anyway, I will report back when we have done our trip.
Thanks again.
Bill

You didnt change the gearbox oil strainer by chance?

Hi JT, no, not this time. I had that done about a year ago and it made a huge difference to the operation of the gearbox. If you are considering doing it, it is well worthwhile.