996 Turbo knock
 

Well very depressing evening today and not a nice post to introduce with. My car has only been back from garage a couple of weeks after having the slave cylinder replaced and new discs fitted. Since getting it back a knock at the rear started and slightly got worse it got quite bad to I called the garage and took it tonight for them to look at. I was thinking maybe a bolt had been left loose after the salve cylinder replacement. Instead been told that they think the gearbox is knakerd and it is being stripped tomorrow to look for damage. It just seems mad as the car was driving fine in all gears.

I was under the car with them for a good while. we removed the front propshaft to see if the noise was coming from their but no it still made the knock. Stood under the car whilst the mechanic put it in first and reverse so we could listen where the knocking was coming from at it does appear to come from the gearbox. Then they drained the gearbox oil to look for any signs of broken metal. There was no big chunks just the faint metalic glimmer in the gunge which my dad thinks would be normal for gearbox wear on a 83000 mile car. The car drives completely fine but over the space of 100 miles got noticably worse. The garage owner has worked on hundreds of turbos and gt2's and was totally stumbled by the noise and said he hadnt ever experienced the same thing/

The knock is like there is slack somewhere in the drivetrain. When I pull away in first there is a knock then if I take my foot off the accelerator their is another knock I can hear it do the same in 2d and 3rd but obviously the pull isnt as harsh in other gears for it to make a knock it also makes a big knock if I reverse it then put it in first and drive forward and vice versus. I just wanted some other opinions and I am so worried about paying out for something massive which could be simple. very nervous as i know this could be very costly.

Any help would be greatly appreciated

Engine or trans mounts checked? Sounds like you have excessive play in the drive train.

gearbox mount was snapped and we replaced that and the knock was still there. we thought that would solve it. I could ask the to check engine mounts

Check the sway bar and links as well since they probably had to remove them to take the tranny out.

Just the fact that it was not there when you dropped it off tells me they caused it during work on the car.... so whatever they took off , changed, replaced needs to get looked at again...