So, I have had the cattle grid for a few months now then the dreaded Trans Fail Safe message, no forward drive, only reverse, turn it off, turn it on all is good. Sent it to the local gearbox specialist in Glasgow who diagnosed gearbox, TC and Oil cooler all goosed, (130K 2004 V. This came with an eye watering estimate pushing £4K.

Bit of digging on the interweb and here and found Birch Motors in Liverpool, genuinely nice guys who only work on the GM and ZF boxes, car shipped down to them, and 3 days later it has been transformed at a fraction of the cost for the same job.

Highly recommend them and as a bonus it came back from Liverpool with all it's wheels

Nice one but did you check for any white powder or plant like wraps in the car?

Can you share the price and what they did in more detail?

I used them 4 and a bit years ago to fix my 4.4 petrol. It was approx £1300 and they did the t/c as well but my oil cooler was ok.
Looking at their website the price hasn’t changed since then. Excellent service and decent blokes. The buildings aren’t what you would call flashy but I couldn’t knock the work they did  2017 Jaguar F Pace 25t Portfolio - still part of the JLR family 😀
2009 3.6 V8 (MY2010) - my first ever diesel! - now also gone
2004 4.4 V8 Petrol Vogue - now gone

I have not called them to check but it looks from their website as if they only do 5 speed ZF gearboxes and not the later 6HP26 for the TDV8. If true it's a pity as their prices look good! Previously a 2008MY Tonga Green Vogue SE 3.6 TDV8