Vauxhall Vectra coming out of 2nd gear in to neutral under throttle pressure

If it's not gear cable / linkage worn , then 2nd gear synchro knackered .Never heard of a driveshaft causing a car to jump out of 2nd gear , that's a good one !!

Thank you I will change cable and linkage first, then go for the 2nd gear sync. Well this is what I thought, I think some garages are just in it for the money.

Unfortunately there are a lot of cowboys in the motor trade nowadays who have never served an apprenticeship and have very little or no training , just a little knowledge picked up but still call themselves mechanics .The customer often pays through the nose for their incorrect diagnose of the fault .Normally if cable /linkage worn , it affects more than the one gear and shows as excessive movement , play on gear stick but worth a look at first though 2nd synchro must be favourite .

Very true I agree, I will mention there is a lag of boost untill I hit 2k then it jerks with power. Changing the synchro is this a job I can do. Ive managed to do most things just when it comes to gear boxes its new education. Or is it worth buying a second hand gear box.

Your taking a chance buying a s/hand box.There are usually plenty of recon specialist locally in the likes of Yellow pages who will supply or recon your box giving a better warranty .But be careful they are an accredited repairer / garage as some leave much to be desired .