Manual to auto conversion?

I have a 2004 Defender Td5 with a standard 5 speed manual transmission. It’s the best Defender I’ve ever owned and has been extremely reliable up to now. all of a sudden 5 th gear has started chattering quite badly; it may be due a new gearbox. ( I haven’t had the noise fully investigated yet)
In the back of my mind I was considering converting to an automatic box if the gear box has to be replaced anyway. Seems like a sensible time to do it.
has anyone done such a conversion before? What do you recommend? Any regrets? What sort of cost am I looking at? What about all the extra details, like fitting the gear selector and removing the clutch etc; what else do I have to think about?

any advice would be welcome!
Thanks

Speak to Ashcrofts.

I am due to collect my TD5 from Ashcroft on Friday... so will let you know...

I was in the same boat, clunky gear changes combined with heavy clutch issues... I have wanted an auto for ages, and my Defender goes really well (touch wood!)... redundancy in my favour gave me the means... it's not cheap though... just hope it's worth it!

Dave at Ashcroft is a mine of information, and will talk you through any concerns/options... I picked them to do the work as they have an excellent reputation, and I have used them for a transfer box exchange and ratio change, which was also well worth the effort.

Well I collected it today... just ahead of the COVID lockdown!!...my drive home on A roads may not have been the best test but Ashcrofts seem to have done an excellent job, you hardly notice the gear changes at all...seems to keep it in the power band quite well, and the kickdown was impressive when I had to nip around a tractor. The interior looks like a standard factory finish - on that note my insurers didn't change my premium.

I'll have to try a weekend in Wales when we're allowed out and off road... and some towing, when the need arises.

It was dark when I got home, but couldn't resist a peek underneath with the torch... nice shiny new bits... but they must have found the leak on my transfer box while they were at it, as it was dry and clean too - yes it has got oil in it!

I had to go back to the standard intercooler, as they needed room for the auto oil cooler.

Very early days, but my initial impression is that it was worth the money.... I just have to get out of the habit of flapping my hand around to change gear...no heavy clutch, so no knee ache, and no notchy gear changes, so no wrist ache - must be getting old...

The heavy clutch on a Defender can be sorted with the assist spring for £25.

Although it's not the best gearbox ever....sometimes mine is smooth and other times obstructive and graunchy.

Our 2006 TD5 was like that from new. The 2003 TD5 l owned had good and bad days, our 2005 90 was OK until it got hot and my 2005 110 also has good and bad days.

Changing the oil can make a difference but the gear change in our new Jimny (effectively the same drivetrain design) is in a different league.