knocking noise help

[payney24]

Hi everyone, i'm after a bit of help and advice. i've got a 2001 leon cupra. i've replaced the subframe and dog bone mount as the originals were accident damaged on an incorrectly fitted manhole cover. the replacement parts weren't new but located from scrappies. however since these have been fitted there is a knocking noise under heavy braking. this not continual but a single knock when jumping on the anchors. it doesn't make this knock under normal driving only heavy braking. i can only presume it has something to do with the newly fitted parts. everything was well tightend when replaced. could it be a worn dog bone or subframe bush? has anyone come across this before or can any one shed any light on this? any help or advice would be welcome.

 

[Willie]

Try tightening your wish bone bolts tighter, mine did this and this is where the looseness was

 

[payney24]

Cheers willie, i'll try and get under the car sometime this weekend and get a bit more manly with the bolts, see if that makes a difference

 

[payney24]

gave it a go this morning, all wishbone and subframe bolts were tight but the bolts on the dogbone mount tightened an extra 1/8th of a turn. not given it a proper run out yet but first impressions are it appeares to have sorted it. does that sound viable to have cured this??

 

[james walker]

if db bolts not torqued correctly, the gearbox will move under load and knock the db mount into the subframe... be sure you didnt overtighten and torqued to the specified amount... too tight and the bolts will snap into the subframe.

 

[Willie]

As above, perhaps best to remove these bolts and refit them to the correct torque then 90 degree further rotation.
As these are stretch bolts best to get new Seat ones to be sure.
Try David @ Sere Motors (forum sponsor)

 

[payney24]

cheers guys, i might try that, anyone know where i can get the proper torque infomation from?

 

[Willie]

on here
search

 

[Willie]

Mount to subframe 20NM + a further 90 degrees
Or 16ft-lbs