Ive had a knocking noise on the left side for a few weeks now, after going through the various check of bushes etc I noticed a lot of play when moving the inner cv joint up and down. After removing the driveshaft, I realised the play is actually not the cv joint but is in the diff flange / cup that the driveshaft is bolted too. There's around 2/3mm play up and down and a metal on metal knocking - as per the attached short video. Only appears to be play on this side of the car. 

Not sure if it's likely to be the diff bearings that are shot, meaning the whole diff has got play in it. Or maybe something else? can't think what else it could be though. Be grateful for any ideas. Recon gearbox maybe? or hopefully something more simple. 

 

Thanks

 

 

 

I had a similar issue with the 6 speed manual gearbox on our son's 2011 1.2tsi Octavia Estate a year ago.

 

While investigating a gearbox oil leak with the car up on ramps the independent mechanic grabbed the output shafts and twisted them in opposite directions and the the output flanges moved in/out by 10mm+ !!

Due to it being an NBW gearbox code, at the time no replacement was available anywhere but fortunately he referred me to a great local gearbox specialist who knew straight away what the problem was, quite common with high mileage VAG manual gearboxes.

 

Both diff output bearings were shot. Probably caused by a slow gearbox leak from the shaft seals over the years that left hardly half a litre gearbox oil in.

 

Removed box, stripped and replaced both diff output bearings and seals for £650. Noted some blueing on the gears indicating overheating due to exteme low oil.

 

Fortunately gears not black which is when they are totally knacked and case hardening gone. If I had left it any longer it would soon have started eating through the inside of the casing and at best would require a complete new diff and pinion which is much more expensive, at worst it would be scrap. So don't delay....

 

Gearbox code is on the boot PR build code sticker. Might also have the PR code sticker on your service booklet.

 

Edited 25 February, 20233 yr by xman

Thanks for that, I'll take it apart and see what the damage is.