[moltuae]

I've just checked my last invoice but it doesn't say, though I'm fairly sure they drop the pan. I did ask once and, IIRC, they said that they replaced the filter and even analysed the old transmission fluid to check for signs of mechanical wear.

The last couple of annual services I've had at Mackie's were a requirement of the warranty agreement (on the gearbox rebuild they did for me a few years ago), so I would imagine they'd want to make sure those services were pretty thorough, partly because they're going to want to give the gearbox the best chance of outlasting the warranty and partly because it's a mandatory service that needs to be performed, regardless of cost, in order to preserve the warranty.

I have had quotes for a full 'fluid and filter' service from local transmission specialists in the past. Most were about the same price as Mackie or marginally more expensive, so I would say £150-£200 seems to be about the norm. When I factor-in the 400 mile round-trip, overnight accommodation and sight-seeing, my annual trip to Mackie gets quite expensive, but for me it's worthwhile and reassuring, knowing that if they find something wrong it's in the right place to get it fixed.