ACD vs 4T gearbox

Can anyone tell me the difference between an ACD and 4T gearbox and if it would be a straight swap?

Caddy's got a mk2 gtd engine in with a 4T box on it, but has a bad whine in fifth so was thinking of getting the ACD box refurbed that I've got lying about, then swapping them when I get the chance so the caddy's not sitting on the drive for ages

The 4T has a bigger 5th gear so lower revs at motorway speeds, the ACD is a close ratio gearbox so at 70 mph you will be doing 3,500 rpm which may not be good for a Diesel engine.

You will need to check what size gearbox flanges you have but they can be swapped from 90mm to 100mm

Have you check the gearbox oil level as 5th suffers 1st from low oil level and if the oil is older than a 40,000 miles or 4-5 years old it's worth changing the oil as it's often overlooked.

More info on gearboxes

Welcome to BrokeVW.com

Not a good idea to put a petrol box on a td. I wanted the longest gearing possible on my1.9td as would top out at 90mph and that was with mk3 td gearbox.

Also i think it's fairly easy to change the 5th gear http://www.brokevw.com/5thswap.html

Ok thanks for the help, I'll try change the oil first to see if that makes a difference.

I've found some comma sx75w-90 GL-4 semi synthetic, would that be ok for the gearbox?

I've switched to fully synthetic and use this stuff in both my cars.

https://www.eurocarparts.com/p/triple-qx-75w-80-api-gl4-5-fully-synthetic-1-ltr-522776282


£8.09 each with MID60 discount code

2l is plenty, just make sure you can undo the filler plug (on the side of the gearbox) before you undo the drain plug.


more info here.
http://www.brokevw.com/020oil.html