Jerky Automatic Gearbox - Martin Simpson.
This is a new one on me.

I own a Rover 623SLi Auto and the action of the gearbox is puzzling me. It's not the most responsive of gearboxes but it's usually a smooth unit. However, lately it's jerky in engaging first initially but after a few miles is OK. Putting it in reverse sometimes is a noisy affair. It's worse on a hill moving from P to R is really noisy usually a mechanical thump but it drives OK.

It's been like this on and off for about 1000 miles, the diagnostic light for the gearbox hasn't gone on.

I'm wondering if it's something to get worried about or not. The fluid is fine and I'm stumped and worried about having to get the credit card out for a right hammering!!

Any ideas guys?
Rover 600 Gearboxes - Michael Thomas
I own a 623 Auto and they are Honda units and usually very reliable. Is it jerky in first from stationery and not from 1st to 2nd but not in 2 to 3 to 4 ?

If it's jerking from 1st to 2nd and also thumping from P to R it's hard to say but my guess is the torque converter could be on the way out.

I don't know about cost but an automatic specialist might be your best bet.
Re: Rover 600 Gearboxes - Andrew Moorey (Tune-Up Ltd.)
Before giving your vehicle to a specialist, (Trevor King comes highly recommended) try draining the 'box and refilling with fresh fluid dosed with Forte Automatic Gearbox Conditioner. I have used this treatment on a variety of 'boxes and the transformation has been remarkable, smoothing the engagement and shifts dramatically. If there is something drastically wrong with the 'box then it won't help but it has got to be worth a shot?