Gearbox problems - ideas?

[matt_ali_walsh]

We were away on the weekend towing a horse float with two big horses and a loaded car. The float weighs about 2T loaded.
In the hills, I went to accelerate up an on ramp, and the box wouldn't kick down. It eventually did, but then we had no gears above 3rd and a big "F" in the dash display. A shut down and restart got us going again, but it faulted again soon after.
I scanned for codes, and got P073-00(6D) Incorrect gear ratio, and P0735-00(ED) Incorrect gear ratio.
Rang my dealer, who are normally really helpful but the new service advisor there wouldn't help me at all, despite us being 250k distant. I've yet to speak to management there, but that's another story.
The pan was changed about 10K ago, I understand it had a pan change at 140K, the car has done a bit over 200K.
I drove home in sport mode, but still had it go faulty once. It won't fault without a heavy load, or on the flat. We live near Echuca, so finding hills is a bit tricky......
Any ideas? Someone must have seen a fault like this?

[~Rich~]

Hi Matt,
What fluid did they use in the auto last service?
Perhaps it is not compatible and thus throwing up those error codes, I had similar faults and codes read this thread:
http://www.aulro.com/afvb/d3-d4-rrs/...ml#post1882968

You closest proper ZF specialist would be Cohuna Automatics - Bob Traynor:
auto transmissions Cohuna

Cheers Rich

[LRD414]

P0735 is often indicative of a recon/replacement transmission in the near future.
That is unless you have been experiencing shudders as mentioned by Rich, in which case flushing and/or Dr Tranny may be your answer.
But your symptoms sound like the stories in these threads (Disco3 & AULRO):

DISCO3.CO.UK - 6-sp auto gearbox flushes, faults, failure and 'finking'
DISCO3.CO.UK - Transmission Fault (Limited Gears Available) when overtaking
DISCO3.CO.UK - gear box fault.
DISCO3.CO.UK - Transmission

Depending on the year you could have the transmission with soft bushes:
http://www.aulro.com/../222394-transmission-fault-message.html
http://www.aulro.com/../163791-trial-tribulations.html

Regards,
Scott