I was mocking up my brakes yesterday and sadly ran into a problem with a different thread pitch bolt. The top bolt is the correct thread but too short. The bottom bolt is the correct length but the wrong thread! lol I have ordered the correct thread and length bolt now, However the factory bolt (bottom) has a serrated washer built in. Does anyone know where i can get these (m14) washers? It's a bit like a nord-lock washer but not two halfs, It's in one piece. This bolt holds the brake calliper bracket to the hub. The hub is alloy so it's better to have some kind of washer to spread the load and not dig into the metal. Cheers Mat
Buy Nord-Locks and use one half on each bolt to replicate the original OEM. The original OEM with 'Washered Head' are beautiful! The only difference will be that the Nord-Locks will not be retained by the thread, unless you buy undersized Nord-Locks and tap them to the thread diameter and turn off the last threads under the head. Which is probably what I would do! Don't use 'Coppa-Slip', use Loctite BLUE instead. Put a copious amount on and the Loctite will stop water penetration and hence stop rust forming in the threads. I use Loctite on all threads for this very reason even with 'NYLOC' type nuts! GREEN, BLUE or RED as the situation requires. I would only use serrated washers in non load bearing applications. They are for vibration protection only on low strength joints. The original design will use a hardened washer, as are Nord-Locks. The large washered head, coupled with the larger serrated washer will spread the load carried into the joint.
The bolt on the extreme left is from the CV joints of my 90Q 20V. Just about the most beautiful bolt I have ever seen!. The one next to it is the ****ty replacement. The idiots at VAG who permitted the replacement obviously are accountants not Engineers!
I have used plenty of those before but i don't think they are correct for this application sadly. I have a feeling they would not "bite" into the bolt/hub enough to lock it as such. Thanks Dave. I don't have a lathe to do that! lol The backside of the nord-lock is not serrated sadly as i did also think of splitting them but was not sure of what the other side would to the bolt of the head. I bought a big bottle of Loctite Blue the other day in prep for fitting all these. I got sick of the little bottles going hard and paying a fortune for them. My other plan is to stick these washers in the vice and undo the bolt so it forces it out. But that does mean these bolts are now scrap and they cost 16 for 4! Cheers Mat
try this one https://www.grampianfasteners.com/category/4778 this place is local to both me and Andrew could easily pop round some time if you know what you want as it is just round the corner from my work
I never realised that the washer face under the head of the bolt was also serrated! Which is pretty unobservant of me as I went through a similar exercise when fitting Sachs SRE Coilovers to Lainey's 25J Mk4. Modified to do the job. Now I have just been out to look at the original bolts that I removed from the rear shocker mounts and they are serrated under the bolt head and under the washer! The new ones are the 4 in the 2nd and 3rd pods. As you will note, the ones I bought to modify are not serrated under the washer, nor, IIRC under the head. So. One wonders what they are trying to achieve in each case? As I have designed literally thousands of bolted joints in my career I have, in the past, looked at every form of torque control, stretch and anti-loosening types one could consider. The most exotic were 'Rota-Bolts'! With these, the main bolt is drilled and tapped down its length and a second, much smaller bolt is screwed down the hole. This second bolt has a thick washer under its head and the system is to tighten the second 'check' bolt down until the gap under the head is exactly the amount of stretch required to give correct pre-load. One can the just tighten the main bolt without worrying about torque or 'part-turn' as when the small bolt's washer cannot be turned by hand then the stretch is correct and hence the pre-load is correct. These were used on high integrity machines for the nuclear industry. Also, it is easy to inspect initially for correct pre-load and later check for loosening, after the machine is run-in, as on any loose bolt the small washer can be rotated by hand. Now, back to these two types used by VW. The one I used is probably designed as a pre-load stretch bolt. i.e. Torque and part-turn. The washer is definitely hardened and retained on a larger than thread diameter by a rolled-in pair of rings. Similar to the AUDI CV joint bolt. Of course, no serrations are wanted as they would affected the control torque! The other double serrated design confuses me! On Nord-Locks, small outside serrations are designed to dig into the softer materials of fastener and parent component so the whole lot, including washer, won't rotate, and the main 'ramp' serrations between the washers is designed to stop the fastener rotating as it would have to climb up the slope. On the VAG bolt one assumes that the washer is harder than the parent component and the washer serrations will dig in!? But, unless the washer is softer than the bolt, the bolt head serrations won't dig into the washer!? On the old bolts there is no evidence of the head serrations digging into the washer!
As I`ve shared in my build, I used to suffer from the passenger side hub nut loosening. Fitted Nordlocks and they NEVER loosen now. I can`t recommend them highly enough TBH
Ah, So i could use a complete nordlock. Didn't think of that! lol The new bolts should be here any day so i will check on the length and see what i have to play with. Dave, The bolt and washer seem of the same material so i also thought about the issue of it not digging into the head bolt. On the alloy hub there are markings around the bolt hole where the serrated washer and dug into the material. Another of my concerns is the diameter of the head on my new cap head bolts (and the VW Racing bolts supplied) compared to the diameter of the VW bolt head even without taking the washer into account. I think the nord-lock is the answer to be honest, Even if it doesnt bite into the bolt head the locktite should hold it. I will have to keep my eye on it.
Mat. I was looking to buy a new bottle of LOCTITE 242 'BLUE' this Amazon offer is a good price. My own 50 ml. bottle is about 20 years old and there is still some left, and I use the stuff all, over so it's worth buying the larger unit! They also have other LOCTITE products relatively cheap! Dave. https://www.amazon.co.uk/dp/B00XJBK...TF8&colid=368B5RMH921DC&coliid=I1AXQH2E9DFJGS
