Flex disc Torque Procedure

maxcbrdriver · 05-07-2023, 07:12 PM

Hi all - I just installed my AS SSK and in the process of doing that, I lowered the front drive shaft. Now I'm putting everything back to together and running into difficulties setting the correct torque. Spec is 55 Nm plus 90 degrees. I've torqued to 55Nm but I'm unsure of the correct method for executing the 90 degrees. At first, since it's very difficult to access the nuts as they are on the transmission side, I out of desperation, held the nut still with the wrench I could get on it and used an impact gun to rotate the bolt 90 degrees. I then had second thoughts and went back to manual and it says to tighten the nut side only. So since I had an extra set of bolts, I removed those tightened by the impact gun. Now I'm going through manual some more and they say

"Brace mounting bolts of flexible disc on nut and tighten by screw"
https://www.newtis.info/tisv2/a/en/f...ion/1VnYXQldsQ

They show all image of an angle measurement device attached to the body of the car and measuring the rotation of the bolt. It appears they are saying to tighten the nut until the bolt side rotates 90 degrees. Does that make sense?

Now I'm worried I've damaged the flex disc by using the impact to rotate bolt and don't have a means of doing it the right way.

Any help is appreciated?

TheHaze · 05-07-2023, 07:40 PM

It's been a few years since I installed the ssk on my car, but I vaguely remember wedging a wrench between the nut and the body of the car so it wouldn't move. Then I just made a white mark on the bolts and another mark 90° clockwise on the flex disc so I knew how far to tighten them.

05-07-2023, 07:12 PM	#1
maxcbrdriver Second Lieutenant 168 Rep 287 Posts Drives: 2010 BMW 535xiT; 2021 BMW M2C Join Date: Jul 2015 Location: NJ iTrader: (1)	Flex disc Torque Procedure Hi all - I just installed my AS SSK and in the process of doing that, I lowered the front drive shaft. Now I'm putting everything back to together and running into difficulties setting the correct torque. Spec is 55 Nm plus 90 degrees. I've torqued to 55Nm but I'm unsure of the correct method for executing the 90 degrees. At first, since it's very difficult to access the nuts as they are on the transmission side, I out of desperation, held the nut still with the wrench I could get on it and used an impact gun to rotate the bolt 90 degrees. I then had second thoughts and went back to manual and it says to tighten the nut side only. So since I had an extra set of bolts, I removed those tightened by the impact gun. Now I'm going through manual some more and they say "Brace mounting bolts of flexible disc on nut and tighten by screw" https://www.newtis.info/tisv2/a/en/f...ion/1VnYXQldsQ They show all image of an angle measurement device attached to the body of the car and measuring the rotation of the bolt. It appears they are saying to tighten the nut until the bolt side rotates 90 degrees. Does that make sense? Now I'm worried I've damaged the flex disc by using the impact to rotate bolt and don't have a means of doing it the right way. Any help is appreciated?
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05-07-2023, 07:40 PM	#2
TheHaze Second Lieutenant 152 Rep 211 Posts Drives: '18 M2 Join Date: Jul 2018 Location: PA iTrader: (0)	It's been a few years since I installed the ssk on my car, but I vaguely remember wedging a wrench between the nut and the body of the car so it wouldn't move. Then I just made a white mark on the bolts and another mark 90° clockwise on the flex disc so I knew how far to tighten them.
	Appreciate 0 Quote