should I use threadlock

[saltyrob]

Good Morning,

I am about to replace the engine mounts and would appreciate advice on whether threadlock should be used on the bolts attaching the mounts to the engine and other bits,

If required what type would be advisable as a quick look at the Loctite product page specifies low,med and high strength.

Many thanks

Rob

 

[Seajet]

Not sure about 'Low, Med, High,' but on military aircraft we used grade 221 for things we'd like to undo sometime soon but not vibrate loose in the meantime, and grade 290 for a more permanent fix, undo-able but with a lot more effort.

I'd have thought engine mounts don't require frequent maintenance, but are subject to vibration, so I'd go for 290 - presumably 'High' ?

 

[macd]

More critical for you, I'd have thought, is whether the nuts are nylocs (litle plastic insert, usually blue, inside one end of thread). They should be.

On endurance racing bikes we had a similar approach to Seajet: nutlock (Loctite 242) for fasteners regularly undone, studlock (Loctite 271) for semi-permanent fasters.

Having said that, Loctite 242 (or equivalent) on nylocs should be sound for your use. If you do need to replace an engine mount, the last thing you need is to be faffing about in the engine bay with a blowtorch. If still in doubt, add a second locking nut above the nyloc, assuming there's sufficient thread. That would be the belt, braces and glueing-your-pants-to-your-shirt approach.

See: www.loctiteproducts.com/threadlockers.shtml

 

[Poignard]

Spring washers

I just use these:

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0275737

Simple to use. No degreasing needed. Readily available. Never 'goes off' in the tube. Cheap as chips!

 

[SHUG]

Nyloc nuts are a reliable fixing for engine mounts.
See here for example http://www.orbitalfasteners.co.uk/products/B--Hex-Nyloc-Nuts-DIN-982-2670/1.html