Lockwashers revisited

[lippy]

I know there've been posts on this in the past that have said split lockwashers are useless. Live and learn, I never would've guessed. I hate the way they dig into surfaces anyway, so I'll be glad to get rid of them.

At any rate, I asked my brother in-law, who works at Monterey restoring high $ vintage racers. He told me they only use them when they are required for correctness. Otherwise, they use different types of locking nuts or Loctite.

I also sent an email to ARP tech support (below), and I thought their response was interesting.

So my take is that you should just use thread lube, proper torque, and flat washers for bolts, with Loctite for particularly difficult vibration applications. But what do you do when you need the non-galling properties of thread lube (say a stainless bolt in an aluminum block) but you want to use Loctite? The Loctite requires a clean thread so you can't use both.

Email from ARP

Jeff,

We have never made or sold any lock washers for any of our products. Calibrated torque with a specific lube is all you need. A bolt is like a big spring, when you tighten it stretches and that holds everything together. Normally we recommend washers with most installations, it helps to keep from damaging the contact surfaces. On high strength fasteners, head bolts, mains, flywheels etc. our washers have a known surface finish (roughness) which promotes consistent clamping loads and using our high strength bolts we supply ID chamfered washers to properly fit up to the head of the bolt.

Always the rule: If you change the lube you change the torque. That's why we supply our lube with most of our kits & torque specs. On the bolts for a pulley to the balancer you could use blue Loctite, washers we supply and appropriate torque for the bolts you have.

Best regards,
Alan
Sales & Technical


QUESTION:
I just purchased a bunch of your bolts plus your ARP lube. I noticed none comes with lock washers. I then Googled lock washers and read that many studies say they're useless. What do you recommend? For example, on the bolts that hold a pulley onto a balancer or water pump, would you just use the bolt (with or without a washer) and blue Loctite, no lockwasher? Also, when should I use a flat washer and when should I leave it off?