Please note: The requirements for the crank pulley bolt are: 90Nm + 180 deg. The requirements for the flywheel (pressure plate) bolts are: 30Nm + 90 deg. Oil is no longer specified by VAG on the later, pre-threadlock bolts. If you use oil, on the latest pre-threadlock bolts from VAG, the threadlock will not work! Check the link below, and the links within that link, for more detailed information on the fitting of flywheel bolts. This gives references to: VWMS recommendations ARP recommendations VAG recommendations for the latest dry pre threadlocked bolts You can easily make your own crank locking tool from an Audi 100 lower link, as shown. Loctite threadlock lubricity is covered on the Loctite Tech data sheets, and is equivalent to a lightly oiled thread, to quote: Lubricity, ASTM D5648, K value, ASTM D 5648, %: 3/8 x 16 Phosphate & Oil Nuts, Bolts, Steel Washer See link within link, for a description of what is meant by a 'lightly oiled thread'. ASTM D5648 is defined as below: 1. Scope 1.1 This test method covers the determination of the torque-tension relationship (lubricity) of adhesives used for locking and sealing threaded fasteners. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. VAG will have taken this 'K' value into account when determining the the Torque + Turn recommendations. Even so, if you read further into the calculation of pre-loads in bolts due do torque tightening methods, you will find in is not an exact science. For extreme accuracy in determining pre-load in bolts, other methods are used. eg. Load Indicating Washers, Rota-Bolts, Hydraulic Tensioner, etc. I have used all of these methods when designing High Integrity Machines for the Nuclear Industry: Sizewell B, Sellafield, etc. A small example of one of my designs:
They contradict each other??? Unless I am going mad, the ABF manual I have states that it is 90Nm plus 90 degrees, the flywheel bolts are 60Nm plus 90 degrees and the only bolts that require 180 degrees are cylinder head bolts? The new bolt I installed had no factory applied threadlock (unlike the flywheel bolts that came with the clutch) You`ve got me worried now! Who is correct?
My fault. I must have miss-read G60RCaol. I assumed it was a 2.0L 16v engine using the M14 x 1.5 pitch bolt. No engine code given. The Mk3 2.0L kit car uses an M14 x 1.5 Crank pulley bolt! So I now assume that not all 2.0L 16vs use this bolt? I don't have factory figures for this bolt! Lubricated could mean lightly oiled or Loctite or MoS2 or Coppa Slip. The lubricity of Loctite is equivalent to lightly oiled. Loctite contains long chain polymers which are the lubricating components. The problem with the word "lubricated" is that the lubricant is not defined. Molykote quote figures between their lightest oil = 0.2mu and 0.1mu for their best. ie. Light oils are no better than dry threads, the oil is pressed out of the joint at quite low pressures, which are usually taken as 0.2 When quoting torque figures, the exact type of lubricant should be specified. If you apply the same torque to a lightly oiled thread and a thread coated with MoS2, then the pre-load in the bolt would be approx. twice on the MoS2 lubricated joint. The figures I quoted were for Mk2, Audi 80 & 90 engines (B3) and Mk3 Kit Car Manual. Bentley, Bentley and VWMS. I don't know the ABF engine at all. I would be very grateful if you could post pictures of the engine bolt tightening torques from your ABF manual! I did a few very rough calcs. on the Mk2 Crank Pulley bolt: M14 x 1.5 pitch: Initial pre-load due to 90Nm torque: K (mu) = 0.2 (Dry/Lightly Oiled) Pre-Load = 32 E3 N Load due to 180 deg turn: 475 E3 N Thus, the pre-load is small compared with the part-turn load. Follow your manual, use light oil or Loctite. Neither here nor there when it comes to total pre-load. But, Loctite will give you extra confidence.
I replaced the crank pully last weekend on my 9a due to a damaged keyway and read in the bentely manual that the torque was 90nM + 90deg, however later in the same chapter it states 90nM + 180deg. I set the 90nM and then tryed the 180deg. but could only get about 120deg, at this stage the extension bar was bending.
Just performed a really quick rough check on the pre-load of an M10 x 1.0 pitch bolt. As I don't know the thickness of the flywheel I have used 10mm, as a guess. Pre-load with 30 Nm torque + 90 deg turn = approx 335 E3 N (335 kN or 335,000 N) (15 E3 N from Torque + 320 E3 N from 90 deg) This compares with an M14 x 1.5 pitch with 90 Nm torque + 180 deg turn = approx 500 E3 N. The actual tensile stress in each bolt is of the same order of magnitude. Both will stretch, as the stress is above yield, and that is why these must not be re-used. The shorter the bolting thickness the higher the pre-losd due to a given angle of turn. Long bolts, such as head bolts, may well not be stressed above yield and can sometimes be re-used.
I have just measured the old crank pinion bolt ( not the flywheel bolt ) quoted in the manual as 90Nm plus 90 degrees. It doesnt mention oiling but advice from elsewhere suggested to me it should be and I cant believe you`d torque it dry. The flywheel bolts came with a thread lock already applied and the old ones also had threadlock which I cleaned out with a tap. The crank pinion bolt is a 12 point shouldered bolt 14mm x 40mm and I suggest it is metric fine so 1.0mm pitch?
The crank pulley in my mk3 gti 2.0l AGG was 90Nm + 90 degrees as well, yet looked very similar to the crank pulley bolt from the previous engine, a mk2 gti 1.8 EV, which had a torque setting of 200Nm. I think the manufacturers use the stretch method as it's a more reliable way of applying a preload to highly stressed bolts?
This is ineresting, I borrowed it from a post by twisted on G60 head bolt tightening: Will post properly, once my head is straight, later today!
Thanks, Hilux. If it's M14 x 1.0 pitch then it is third series. M14 x 2.0 p is course. M14 x 1.5 p is fine. If it is 1.0 p, then the load due to part turn, will be less than for a 1.5 p thread, be it 90 deg, or 180 deg. If it is 1.0 p & 90 deg turn, then the load due to turning will be in the order of: 130 E3 N If it is 1.5 p & 90 deg turn, then the load due to turning will be in the order of: 190 E3 N If it is 1.0 p & 180 deg turn, then the load due to turning will be in the order of: 260 E3 N If it is 1.5 p & 180 deg turn, then the load due to turning will be in the order of: 380 E3 N Big difference! Regarding lubrication. This only effects pre-load during initial torqueing. As I stated previously, the type of lube will effect the initial pre-load for a given torque applied. Better lube, more load for same torque. Lubrication will help you to turn the extra part, though, and will not effect the pre-load due to this I agree, you would not necessarily do it dry, but you could, it the torque quoted was for dry threads. The problem is, that without the manual stating exactly which lubricant to use, you can't define a pre-load torque. Under head lube is very important for torqued, and torqued + part turn. Always use a good lube under the head. I use Rocal ASP. It is an extreme pressure paste, similar to the ones noted in the photos below. Another point is, that some bolts do come 'dry', stainless, brass, sherardised, zinc plated, hot dipped galvanised. Black phosphated bolts are usually supplied lightly oiled to prevent rusting in storage. Below is a photo showing various VAG bolts as delivered. The second from left came lightly oiled and 10 years after poor storage has rusted a little. The next two are yellow zinc chromate and cad, I guess, not sure. They have not rusted. The one next to the right hand end is a brake caliper slide bolt. Black phosphate, with locking patch. This is straight out of an ATE sealed plastic bag which I opened today. Still, it has gone rusty as not lightly oiled. The green one is interesting. I've seen quite a few like this recently from VAG. I think this coating is instead of light oiling to stop the workers getting oily hands, and possible dermitits. The two bolts on the left are both Audi Quattro 20v front cv/hub bolts. The very left hand one is the original. 10.9, loose washered head, waisted shank. Beautiful. The second is what they supply now. 8.8, fixed washer, plain shank. 1/10 th the price. I know which is preferable to me. The first one will offer very little under head friction when well lubed. You can see, in the following, that co-efficient s of friction can vary considerably. Yellow Lines are thread mu. Green Lines are under head mu. To sum up: I trust the VAG figures in the previous post. As far as I am concerned I shall use Loctite on the thread of my 1987 EV crank/pulley bolt. I shall lube under the head with Rocal ASP. I shall torque to 90 Nm + 180 deg. VAG chop and change bolt types and grades willy nilly, it appears. There are probably Tech. Service Bulletins to cover these changes, but we don't see them! If you trust the torque figures from your manual, then use them, they amy have seen the relevant Tech. Bulls. If you want to 'lube' the thread, and don't believe Loctite has lubricity values similar to those of light oil, then don't use Loctite. Use whatever lubricant is quoted for the torque figures you use. FINIS.
Fair enough but its in the car, its 90 plus 90 lubed as per the works manual so based on my past experience in building cars I have not seen bolts required to be so tight apart from Porsche/VW hub nuts and some cylinder heads.
