Rear subframe bolts - coppaslip?

[Blink]

Post 9 here recommends using copaslip to prevent the 4 rear subframe bolts from seizing up and becoming difficult to shift again if needs be. It's referring to old bolts. Is it a good idea to use it (or an equivalent product) on new bolts as well?

[trikey]

I have never used copaslip on the subframe mounting bolts, they have always come out time after time for me.

[SD1too]

Originally Posted by Blink

It's referring to old bolts. Is it a good idea to use it (or an equivalent product) on new bolts as well?

My view is yes it is. The principle remains the same whether the bolts are old or new.
Coating the heads in Waxoyl also helps to deter corrosion.

Simon

[clf]

I used a smear of copper grease around the back of the head of the bolt and any mating surfaces for the fail safe washers, knowing I would be sealing the whole lot with underseal. The idea is, whilst the bolts came out incredibly easily, and I have no doubt they will survive in a similar way, but it will reduce the risk of corrosion welding any of the mounting faces together (slim chance of that too lol).

[Randyjim]

Be careful using copperslip on high torque bolts. The reduction in friction can dramatically increase the tension in the bolt unless the torque value is reduced appropriately. It has been know for bolts to snap under this increased tension.

I don't think it's a huge risk, but it is still there.

I'd say it's less risky with old bolts as any corrosion present will increase the friction and you'll tend back towards the correct tension with a bot of lubrication, but it shouldn't be necessary on new bolts.

[marinabrian]

No, these are patchlok bolts so do not lubricate the threaded part with coppaslip.

You can apply a small smear on the flange section of the bolt head, and the plain shank of the bolt, but not the thread itself, a spot of loctite 243 is the stuff to use

Brian

[Blink]

Thanks for all the answers chaps. The general consensus seems to be 'Yes' then (or Loctite 243**) - sorry Trikey.

**Just checked and I've already got a tube of Granville Lock Thread - use instead of Loctite 243 perhaps?

[The Mighty Quinn]

Having seen the bolts that came out from my original rear subframe recently (been in there 16 years), I'd say there's no need to put anything on them. No sign of any grease having been used when they were fitted at the factory - and they came out like brand new items (save for the exposed bolt heads).

I had new bolts and washers to fit the new subframe, but I needn't have bothered..


Cheers,
Karl.

[Blink]

Originally Posted by The Mighty Quinn

..... they came out like brand new items (save for the exposed bolt heads).

I'm thinking of painting all exposed bolts heads (after everything is fitted) to prevent corrosion. Does anyone else paint theirs?