A nut case

Did my 300tdi timing belt today. All went fine , I tightened the 27mm dog nut to 80nm and then tried the extra 90 degree turn as per Mr Haynes , got it to about 60 degrees with 4ft extension bar but I chickened out as it felt I would do damage to threads or brake something.Should I leave it so as its sure not going to loosen off.
PS
don't want to use a thread lock.
Thanks

You wont damage the threads but it should be ok if left.

Thought so. Thanks for opinion anyhow.