Front Suspension Torque Settings & Nut/Bolt Part numbers

[S2central.net]

I've had this info at my fingertips from the factory manuals over the weekend so here goes -

Strut Top to Body (outer nyloc ) - 60Nm (needs VAG3078 or similar slotted 22mm and a hefty 7mm allen key with extension bar)

Strut Top Nut - 50Nm (needs special slotted tool - VW524 - use with 3078)

Track-Rod End (Nyloc) - 30Nm (17mm - note the FINE thread on this one)

Bottom Joint (Nyloc) - 50Nm (17mm with nut facing rear.
Three camber adjusting ribbed nuts on bottom joint - 65Nm

Link rod nuts (Nyloc)- 40Nm (17mm)

Wishbone to subframe bolts - 40Nm plus 180 degrees with vehicle on the ground (unless using Powerflex type bushes which can always rotate). These are stretch bolts which must be renewed on replacement.

Strut to hub carrier - 110Nm plus 90 degrees (22 or 24mm here - note the nuts face forwards on these). Also a stretch bolt that must be renewed.

Inner CV joint on front driveshaft to gearbox - 80Nm (M10 splined)

Front Hub bolt - 200Nm plus 90 degrees. Must be done with vehicle on the ground.

Damper securing ring to strut - 220Nm - needs special tool VAG2069 or similar

Paul

[s2driveruk]

Good info paul, quick numpty question, what is the definition of a stretch bolt, i.e. is it a term for a bolt that should always be replaced, or a physical change in the bolt?

Just wondered cos i have never heard of or asked specifically for a 'stretch' bolt.

As i say, no doubt a stupid question (and BTW the changed all my bolts/nuts when i did mine last year as a matter of course...) but curious of the answer.
Cheers
David

[S2central.net]

@Dave - tis a question best answered by a proper mechanical engineer, but my understanding is that these type of bolts do indeed actually stretch when fully torqued up. Any bolt you see that is XXNm plus Y degrees is a stretch design AFAIK - its those Y degrees that stretch it a little so it keeps the right clamping force on the parts in question. The manual clearly states to replace all such stretch bolts.

Of course, all nyloc style nuts must be renewed as well if you wish to keep up with best practise.

Paul

[S2central.net]

Here's some useful part numbers on the front suspension nuts and bolts - This is 1994 ABY Coupe but should be common with all S2 front-ends. If in doubt, ask --->

N 902 856 02 - Ribbed nuts for balljoint (3-off each side)

N 904 893 01 - M10 wishbone bolt (2-off each side)
N 021 195 5 - M10 nyloc for above

N 906 244 01 - Strut to hub carrier bolt (2-off each side)
N 021 225 3 - Nyloc for above
N 011 534 3 - Washer for above (4-off each side)

N 034 778 4 - Bolt for bottom balljoint (1-off each side)
N 021 195 5 - M10 Nyloc for above (same as wishbone and linkrod nylocs)

N 021 195 5 - M10 Nyloc for link-rod joints (2-off each side)

811 412 365 - Slotted nut on top suspension mount (1-off each side)

N 041 183 5 - Nyloc for top mount (1-off each side)

N 011 189 6 - Nyloc for track-rod end (1-off each side - FINE thread here)

Please do NOT take those for absolute truth - haven't checked them for typos yet !

Paul

[S2central.net]

And some more...

4A0 407 643A - Big Central Hub Bolt (M16 on S2). This is another stretch bolt. Note that it is included with BOTH the hub-bearing kit and CV-boot kits below.

893 498 625E - Front hub bearing kit (82mm). Also contains top mount nyloc, track-rod end nyloc, the lock-bolt and nyloc for the bottom joint and the big hub bolt.

N 030 131 4 - Small M6 bolt that secures brake pipe bracket to strut. 2-off each side.

441 498 203A - Outer CV Boot-Kit (Front). Also contains new circlip for driveshaft, two securing clips for the boot and the big M16 central hub bolt.

Can someone else sanity check my part-numbers here please, they seem OK to me but doing this quickly so you know how it is !

Paul

[Rusty]

Good work Paul. I must stress that the strut to hub bolts are rather important, all my front ones came loose last time I was at the 'ring as I wasn't aware of just how tight they needed to be and that I had to replace them...

[s2driveruk]

sounded good didn't it Andy

[S2central.net]

Glad I was nowhere near that... Sounds like one of those moments when you could fill your undercrackers

Paul

[lind4hl]

you dont have the torque for rear axle also?

[madwolf_Uk]

@Dave - tis a question best answered by a proper mechanical engineer, but my understanding is that these type of bolts do indeed actually stretch when fully torqued up. Any bolt you see that is XXNm plus Y degrees is a stretch design AFAIK - its those Y degrees that stretch it a little so it keeps the right clamping force on the parts in question. The manual clearly states to replace all such stretch bolts.

Of course, all nyloc style nuts must be renewed as well if you wish to keep up with best practise.

Paul

Yep, as good a description as any other

Spot on stuf as allways Paul

[Hexer]

Hello everyone,
Today I started to install the suspension an a B4, on the ftont I using powerflex bushes, ant here come's the problem.
Powerflex gave some bolts in the kit, not like the original on at all. Thea are 8.8 and made on lathe as they center the bush inner tube, because of thees I can't fasten these as the original, they can take at most 130Nm.
Yes, I know that a stifer suspension require "softer" bolts, past 10.9 it cloud brake because int can't flex (hat some problem with 12.5 bolts, kept snapping, with 10.9 no problem.
On the pics I have the original bolt next to powerflex, the original is 10,9 and the thread is mangered (hope I rote correctly the proces), and what is very different, they don't center anything...

The 3. possibility is that I buy 10.9/8.8 centered and mangered thread Yet I don't no





Ps. I found that Wishbone to subframe bolts - 50Nm plus 90 degrees shoud be another option...

[Hexer]

Ups...no photo...

[Lago Blue]

Hexer , good question about the Powerflex bolts (+nuts?)...

As stated near the top of this thread (and as you may know), this bolt has a slightly different job when poly bushes are used vice the OEM's. Originally, the OEM bolt had to lock the stock bushing's core, in the suspension's static loaded position, from ever rotating, as well as simply locating the bush.

With the poly's, whether the core rotates is not so critical (and the fasteners can be tightened without the suspension arms loaded), but accurate location that is not going to shift is still as important (neither bolt totally fills the sub-frame bolt-holes). I suspect that the shank on the Power-flex bolt better fills the Power-flex cores, that's the only advantage they may have.

In my factory manual the torque called for on the OEM <i>nut</i> is 40Nm plus an additional half turn (180 degrees). Do the Power-flex instructions not suggest what torque to use? Do they also supply nuts? If so, are they a self-locking type? If I recall correctly, the factory nuts are an all-metal self-locking type with a nice built-in washer.

I'm not able to get a torque wrench on these. I just put 40 Nm on a wheel nut and see what that feels like, tighten the subject bolts similarly, mark them and add a half-turn. Then I spray them with rust-proofing. I had a different brand of delrin bushes that came with new OEM fasteners (I use OEM bushes and travel limiters now).

If you are concerned, you could use new OEM hardware and the factory reco'd torque.
OEM fasteners and torque may trump the 'fat shank' bolts.

[Jenks]

Jesus H...... I'm all for the correct torque being used on wheel nuts and head bolts etc but lets be realistic here, do you honestly think that powerflex or superflex have had the time or inclination to check the specific torque of every application from an Alfa to a Yugo (sorry too pissed to think of a car that starts with Z). If you haven't got an idea of how tight it should be then leave it to someone with some experience to use 'engineers feel'

[BRY]

Jesus H...... I'm all for the correct torque being used on wheel nuts and head bolts etc but lets be realistic here, do you honestly think that powerflex or superflex have had the time or inclination to check the specific torque of every application from an Alfa to a Yugo (sorry too pissed to think of a car that starts with Z). If you haven't got an idea of how tight it should be then leave it to someone with some experience to use 'engineers feel'

Zagato