Loosing power when towing

[Bidja]

they stuck it on the dyno and loaded it up to towing 2 ton, found all ok apart from a leaking seal which they replaced, now advise me the problem is the transmission and nothing to do with their work,

Barry what seal was replaced?

So what is the story with you having boost/egt gauges? good idea for you to be able to observe behaviour, especially when towing mate.

Maybe get an other opinion before throwing more cash.