X350 DIY gearbox change

Hello again all.

I’d like to hear from anyone who’s changed the auto box in their 3.0 XJ6 with suggestions please.

It appears I’m another ‘victim’ of the infamous torque converter/drive lock/top gear issue where it won’t engage properly and cycles in and out every second or 2, accompanied by a drop in revs and a kind of grinding humming noise. The Jag garage has said they believe it to be the torque converter. The timing of this is miffing me off a bit as I’ve just replaced the brakes all round, fitted a new expansion tank bottle, and sorted an issue with the power rack with new seals and a fluid flush.

The Jag dealer said they can supply and fit a new torque converter which should resolve it, but obviously the cost of parts and the labour cost mean it’s quite expensive and these cars aren’t worth major money anymore. The should bit concerns me too in case any further box damage has been done and more labour charges are incurred to do things further and/or again.

So…

I’m thinking of a second hand box which includes the torque converter and comes with a short warranty, then fit it myself. I can’t see how the physical act of changing the box would be too difficult (I’ve restored a couple of classic motors in the past) but I’m concerned with any electronic compatibility over the X350 life span and maybe getting the correct oil level set.

Advice appreciated please as the car is otherwise very nice with only 98k miles and stamped history so it seems a shame to let it die.

Dave.