Towing suggestions for GU 4.8l 2010

[bjrow]

Hey guys just wondering if there is a preferred towing use for the 5sp auto behind the 4.8l GU.
I am trying to tow a 2.3ton load and normally leave the auto in D but am wondering if manual 4/5 would be a better option to look after the box a bit better.
Also, shifting down as we come up to intersections for added braking does this place additional stress on the auto internally or should I just let it do its job?
Have fitted an external/additional auto cooler.
Look forward to your insights/experience.

[threedogs]

2.3 is about the limit isnt it I wouldnt tow in OD with that weight.
As for changing down I do that everyday and have no problems.

There are mods you can do to lock up the converter and basically drive it as a manual
a few here have done it,

[bjrow]

Thanks Threedogs for the response.
The 4.8 is rated at 3.5T so a bit shy but certainly noticeable load behind. Tows on the flat OK at 100+ but suffers from hills a fair bit, probably used to my old Monaro accelerating up but hey...
In D the converter cuts in/out a fair bit, manually selecting 5th it seems that the converter still attempts to lock up as the rpms drop so maybe 4th is a better option. Just means having the revs sitting around 2300 at 100klm/hr.
As it is, fuel consumption runs at 21.7l/100 going up the Melba, thru Yea, over to Eildon and onto Jerusalem Creek with the load and back. Car laden with 4 adults. Have tried using the auto in manual mode and seems to go thru a bit more juice than leaving it D, just didn't want to overstress the box so wondered which would be a better way to go.