# Rear Suspention Bolt Torque



## bromleyxphil (May 4, 2010)

Hi

Just fitted VB air assist to my van but the instructions don't give torque settings for the bottom bolts. Where can I find or does anyone know this setting? Fitting very straightforward and has already made a difference to ride and height.

Phil

Off to the Moselle in 7 days


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## bromleyxphil (May 4, 2010)

I tried to edit this but was too late. I got the bolts off with my socket set so do we think they will be tight enough put back with my socket set? or is a mischievous Turin mechanic having a laugh!
Phil


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## pneumatician (May 1, 2005)

If you let me know bolt size and grade I can give you the recommended bolt torque. Bearing in mind you must take in to consideration what exactly you are clamping together.

Eg:- Clamping 2 rubber blocks together would not require the same clamp force as 2 blocks of steel.

Measure bolt dia and look at the head where the grade will be specified :- 5.6 , 8.8 , 12.9 etc. If the bolts are cap-heads I can work from that.

Steve


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## bromleyxphil (May 4, 2010)

Hi Steve

They are U bolts and don't seem to have grade markings clamping steel/steel or steel/alloy I am not sure, the diameter is 12mm with a 22mm nut. I have a pic but am not sure how to post it.

Phil


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## pneumatician (May 1, 2005)

U bolts are a bit of a bugger because they are soft joints in that they deform as they take the shape of the axle. So to get the right result you will need to sequence tighten to a lower torque then a final nudge to the required torque. Keep the bolts as central as possible with equal amounts of utilised thread
The "U Bolts" will probably be grade 8 low end high tensile so the final torque should be about 85 Nm. Having achieved this torque you should re-visit after a couple of hours and torque again to 85Nm you will probably find the bolts have stretched. 

Steve


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## spannermanwigan (Jun 28, 2010)

this link is for glide-rite suspension

if in fact you are using original u bolts as they do. these should be 
torqued to 130nm

see appendix. B torque settings
B1. method

http://www.glide-rite.com/v/vspfiles/assets/images/ducato-2009installation -v4.pdf

regards

steve


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## pneumatician (May 1, 2005)

My word the Glideright is a complex system. Designed for a large variation in loads.

However one or two of the figures on their torque table are slightly different to mine.
Problem with U bolts is you are taking it on trust as to what grade they are as there are no identification marks. 
The torque I suggested was grade 8 which is what most "normal" fasteners are on motor vehicles.
If you want to take them to the higher torque do it gently and if you can detect any sense of the rotation becoming easier stop, you will have gone into yield. Next stage is shear. I doubt if you will be able to detect this but it's a possibility. 
The figures given on the Glideright table suggest somewhere between grades 10 and 12 these are the top end "High Tensile" fasteners used on motor vehicles (10.9 & 12.9).
Many fasteners are now tightened to Torque plus angle and finally yield in vehicle production. Fasteners taken to yield should not be reused. 
The above is just MHO based on vehicle assembly bearing in mind I retired eight years ago and the technology could well have advanced somewhat.

Steve


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## joedenise (Jul 20, 2007)

you would need to read instructions a few times before you started,

that would take all day :lol:  :lol: 

joe


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## bromleyxphil (May 4, 2010)

Thanks guys no wonder VB dont put it in their instructions.


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