Rear suspension bolts RYP100150 - Page 5

steve811 · 2nd June 2013, 08:38

Exactly! and why I was only 95% sure!

VMax1000 · 2nd June 2013, 13:08

Been reading through this thread again and compared torque values quoted for the V8 with the others in the range. For the V8 it's 80Nm where the others require 100Nm.

The reason is that toe-in on the V8 is not adjusted via the trailing arm.
On the others, the trailing arm is used to adjust the toe-in.
Hence the difference between the V8 torque values and the rest.

Although the bolts don't take all the load, they're torqued up to provide enough friction between the bracket and the chassis. This is where you need surface area and flanged bolts.

Also 8.8 bolts are not designed to take 100Nm of torque so replacement will have to be 10.9 bolts

Adding 5mm thick washers to cope with point load of socket heads will only increase the lateral load on the bolt.
Better to replace with flanged bolts as per design intent.

steve811 · 2nd June 2013, 17:51

Unfortunately flanged bolts are unobtainable! The bolts I intend using are 12.9, they will take 100Nm quite easily, I doubt if the lateral load is going to be an issue at 100Nm, I can't see any likelihood of slippage or failure. If on the other hand someone can find a supplier of flanged HT bolts?

Froggy-Mk2 · 2nd June 2013, 20:00

Thinking out of the box - so to speak
Hows about using some studding M12 x 1.5 grade 10.9
http://www.ebay.co.uk/itm/Conversion...item1e7ae61860
cut to an appropriate length and used with M12 flanged nuts

steve811 · 2nd June 2013, 20:23

A great idea, and one I prefer, but I can't seem to find 12.9 or even 10.9 flanged nuts!

Froggy-Mk2 · 3rd June 2013, 14:53

Quote:

Originally Posted by steve811

Sorry, should have uploaded the photo!

Looking again at that photo, and Steve's comments on length, it seems to me that the last 10mm of the bolt has no load carrying capabilities. On that basis methinks that a 12M x 1.5P x 40mm flanged head grade 10.9 bolt would be fit-for-purpose. Comments guys

Froggy-Mk2 · 3rd June 2013, 16:09

wrt Flanged nuts, have a look at this link
http://www.blauparts.com/proddetail....N+101+064+02-1
Nut Set - Metric 12 - 1.5p - Nylock Flanged - (10.9) (Set of 10)

Also
BMW Flywheel bolts M12 x 1.5 x 50 Hex Head, full length thread, stamped grade 12.9
Part No. 11222243051
Available here in UK http://www.online-parts.co.uk/bmw/pr...l#.UazTJtLCZ8F

steve811 · 3rd June 2013, 18:54

Thanks, the first link I would have to order 10, which is 69 dollars plus shipping, and then I still have to order the studs, making it around £50 for the lot!

The second link is better but I am still looking at £40 plus VAT making it around £50 again!

I will go with my idea of using the spacers and the socket head bolts, unless someone has a box of the originals somewhere!

Froggy-Mk2 · 3rd June 2013, 20:03

Just found these
http://www.ebay.co.uk/itm/BMW-M12x1-...item43b5a5c4fb

steve811 · 3rd June 2013, 20:19

Better, but would still need spacers to stop the heads bedding in, and at £18 for six a bit cheaper!

2nd June 2013, 13:08	#42
VMax1000 Passed Away MG ZT260 Join Date: May 2007 Location: Swindon Posts: 2,805 Thanks: 62 Thanked 325 Times in 249 Posts	Been reading through this thread again and compared torque values quoted for the V8 with the others in the range. For the V8 it's 80Nm where the others require 100Nm. The reason is that toe-in on the V8 is not adjusted via the trailing arm. On the others, the trailing arm is used to adjust the toe-in. Hence the difference between the V8 torque values and the rest. Although the bolts don't take all the load, they're torqued up to provide enough friction between the bracket and the chassis. This is where you need surface area and flanged bolts. Also 8.8 bolts are not designed to take 100Nm of torque so replacement will have to be 10.9 bolts Adding 5mm thick washers to cope with point load of socket heads will only increase the lateral load on the bolt. Better to replace with flanged bolts as per design intent. Last edited by VMax1000; 2nd June 2013 at 13:10..

3rd June 2013, 16:09	#47
Froggy-Mk2 Loves to post 75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010 Location: Fareham Posts: 366 Thanks: 0 Thanked 0 Times in 0 Posts	wrt Flanged nuts, have a look at this link http://www.blauparts.com/proddetail....N+101+064+02-1 Nut Set - Metric 12 - 1.5p - Nylock Flanged - (10.9) (Set of 10) Also BMW Flywheel bolts M12 x 1.5 x 50 Hex Head, full length thread, stamped grade 12.9 Part No. 11222243051 Available here in UK http://www.online-parts.co.uk/bmw/pr...l#.UazTJtLCZ8F Last edited by Froggy-Mk2; 3rd June 2013 at 17:35..

2nd June 2013, 08:38	#41
steve811 Banned Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010 Location: Newport Posts: 1,906 Thanks: 107 Thanked 299 Times in 206 Posts	Exactly! and why I was only 95% sure!

2nd June 2013, 17:51	#43
steve811 Banned Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010 Location: Newport Posts: 1,906 Thanks: 107 Thanked 299 Times in 206 Posts	Unfortunately flanged bolts are unobtainable! The bolts I intend using are 12.9, they will take 100Nm quite easily, I doubt if the lateral load is going to be an issue at 100Nm, I can't see any likelihood of slippage or failure. If on the other hand someone can find a supplier of flanged HT bolts?

2nd June 2013, 20:00	#44
Froggy-Mk2 Loves to post 75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010 Location: Fareham Posts: 366 Thanks: 0 Thanked 0 Times in 0 Posts	Thinking out of the box - so to speak Hows about using some studding M12 x 1.5 grade 10.9 http://www.ebay.co.uk/itm/Conversion...item1e7ae61860 cut to an appropriate length and used with M12 flanged nuts

2nd June 2013, 20:23	#45
steve811 Banned Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010 Location: Newport Posts: 1,906 Thanks: 107 Thanked 299 Times in 206 Posts	A great idea, and one I prefer, but I can't seem to find 12.9 or even 10.9 flanged nuts!

3rd June 2013, 18:54	#48
steve811 Banned Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010 Location: Newport Posts: 1,906 Thanks: 107 Thanked 299 Times in 206 Posts	Thanks, the first link I would have to order 10, which is 69 dollars plus shipping, and then I still have to order the studs, making it around £50 for the lot! The second link is better but I am still looking at £40 plus VAT making it around £50 again! I will go with my idea of using the spacers and the socket head bolts, unless someone has a box of the originals somewhere!

3rd June 2013, 20:03	#49
Froggy-Mk2 Loves to post 75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010 Location: Fareham Posts: 366 Thanks: 0 Thanked 0 Times in 0 Posts	Just found these http://www.ebay.co.uk/itm/BMW-M12x1-...item43b5a5c4fb

3rd June 2013, 20:19	#50
steve811 Banned Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010 Location: Newport Posts: 1,906 Thanks: 107 Thanked 299 Times in 206 Posts	Better, but would still need spacers to stop the heads bedding in, and at £18 for six a bit cheaper!