Flexplate bolt tension

centy · #1 23-08-2008, 10:28 PM

Does anyone know the correct tension for vp series 2 flexplate bolts?
I sorts titened some to firm and heard a cracking noise so now need a few new ones.
Sucks to be big and have tools that don't break.

Morton · #2 23-08-2008, 10:33 PM

Is it a V6?

Torque them up to 20Nm to start with, working in an opposite diagonal pattern, then when they're all at 20Nm, tighten each one an additional 73 degrees.

Keep in mind that on a VP, you should be discarding the old flexplate bolts and replacing them with new ones. If you can, chase up an ARP bolt kit, and some ARP assembly lube, which will come with its own torquing specifications. You want to be really careful with how you do this, because driveplates can cause big problems if they crack or shudder. I've basically smashed a driveplate on my old VP

centy · #3 23-08-2008, 10:38 PM

they are very small bolts,

Morton · #4 23-08-2008, 10:41 PM

Very small? Sounds like torque converter bolts. Which of the following do you wish to know:

flexplate/driveplate -> crank (there are six of these)
torque converter -> flexplate/driveplate (there are three of these)

centy · #5 24-08-2008, 12:05 AM

flexplate to crank.
I thought it was 8 bolts not 6.
i know that flexplate to converter are supposed to be 40-45nm but was doing the crank bolts up firm and snapped one.
Ok so my idea of firm is probably 75ft lbs.
I tend to snap bolts.

jas98 · #6 24-08-2008, 12:21 AM

yeh the series one (vn etc) you could do them up tight and i believe u could reuse the bolts.....but on series 2 engines (vn series 2, vp etc) you had to replace the bolts do them up very lightly compared to the series one then as said tighten a further amount of degree otherwise,(for example your case), you can snap the bolts.

Morton · #7 24-08-2008, 12:25 AM

Quote:

Originally Posted by jas98

yeh the series one (vn etc) you could do them up tight and i believe u could reuse the bolts.....but on series 2 engines (vn series 2, vp etc) you had to replace the bolts do them up very lightly compared to the series one then as said tighten a further amount of degree otherwise,(for example your case), you can snap the bolts.

Yup

That's right. Have to replace the bolts. 20Nm, then a further 73 degrees. That's what I did on the VP, and it worked a treat.

Lots of things changed from early VNs to the S2 and VP onward motors. Even the rear main seals, cams, and inlet manifold lengths were different.