If you are climbing an Alp, with chains, the BW35 autobox gets a bit hot and bothered. It is, after all, suffering a bit of cognitive dissonance: I'm supposed to to be transmitting energy from the engine to the road, but the road isn't solid. The BW35 is not a modern, electronic autobox, but it still does its job perfectly well if you treat it properly.
So you need to take it slow. The carb is gasping a bit at the thin, cold air too. It's a good idea to adjust the mixture a bit as you climb. I am sure members who live in Norway, Northern Sweden, Switzerland do this anyway.
***Use CB***. The HGV road hauliers have times and budgets to meet, and a car making 50 km/h (the legal minimum) in the slow lane is stopping them making their targets.
Talk to them, they will box you in, two in front, two behind, one to the left of you.
They are totally happy about this. You are helping them meet their targets, and they get to see a beautiful classic car. If they weren't interested in motoring, they wouldn'd be doing their job.
Don't worry about the language issue. Most HGV drivers speak English to some extent.
If it's an automatic, you need to adjust the mixture every 2000 metres of altitude. You can buy altitude meters for pennies on the internet. You just take the mix down by a sixth of a turn. Remember to enrich again when you come down. This is especially important as fuel in Italy is now E85 and burns hot.
The poor little 1800 cc engine will be gasping with the reduced mixture. It's a heavy car and not that big an engine. Take it easy. In the middle of the tunnel, the highest point, you have the performance of a 900 cc vehicle.
There are constant patrols on both sides because they really don't want an unfit vehicle to get stuck in a tunnel. I ring them beforehand, pull over about a kilometre before I enter the tunnel, lift the bonnet, make the adjustment, and wait. Normally not more than a couple of minutes.
If you are on the Italian side, the Polizia Stradale speak English.
On the French side, you may want to write down and print off the following phrase:
'I need to adjust the carburettor of this vehicle so it will not stall in the tunnel.'
'Je dois régler le carburateur de ce véhicule afin de ne pas caler dans le tunnel.'
You'll go through the tunnel with a police car in front and a police car behind. They put up the 50 signs. That's 50 km/h, 30 mph. The 1800 doesn't get hot and bothered at 50 km/h, even at the summit.
They don't really have a lot to do, it's not a frontier any more, but they hate breakdowns in the tunnel, and the second police officer gets to inspect all the lorries going by. He sits behind the driver, on the left, and has a camera.
The Italian cars have the candystripes, the French ones are usually unmarked. Everyone speeds past the unmarked French cars and get stopped and fined on the Italian side.
The police have full communication through all of the tunnels. Because the Italian police cars have the candystripes, they sometimes just put up the 50 limit, and put an officer with a radio in my motor car. As it's RHD, she is on the left and can look at all the vehicles overtaking me, illegally.
Polizia Stradale literally means 'Road Police', Italy has several police forces. Polizia Stradale are normally quite interested in cars. They are not your friendly English Bobby on the beat, their aim is to get convictions, but if you speak to them nicely, and admire their cars, they can be quite co-operative.
Putting up the 50 sign slows traffic through the tunnel enormously, and causes huge tailbacks, but they'll do it, not so much because of the risk of the 1800 breaking down in the tunnel, but because they get so many convictions for speeding.
Because other communications don't work in tunnels, people don't realise that the police communications do.