11 replies to this topic

[087dave]

Hi all

When attaching the clutch housing to block is it better to use studs or bolts?

As I don't have the lock tabs as they didn't come with my engine..
Tks

[Stiggytoo]

Either is fine. Just use loctite on the threads.

[AlexMozza]

Lock tabs are rubbish anyway.

Loctite will usually do the trick, to be extra safe you could use a spring washer too. 

[Cooperman]

Best to use bolts into the cast iron block and studs into the aluminium gearbox casing. Mini Spares do a complete bolt & stud set.

[Guess-Works.com]

either, just do them to the correct torque or you're likely to over tighten which will cause issues with idler gear shimming and oil leaks.

[Cooperman]

The reason it's best to use studs into aluminium is to reduce the fatigue stress of screwing bolts into aluminium repeatedly. It causes the threads to break up (eventually), so studs which turn against the aluminium only have to be tightened once and even then not with a high torque. Also, the coarser threads in aluminium castings will increase the fatigue stress.

If using bolts into aluminium it is best to use Heli-Coils in the aluminium and in aero engines it is a mandatory requirement.

[087dave]

Thanks guys

Mini spares don't do lock tabs as far as I can see

I just don't know about putting loctite just on the nuts would also like to use the lock tabs

[Cooperman]

Lock tabs are not necessary. Just use Loctite.

[Spider]

Lock tabs are not necessary. Just use Loctite.

 

I agree on the locktabs. I just use new spring washers.

[Cooperman]

 

Lock tabs are not necessary. Just use Loctite.

 

I agree on the locktabs. I just use new spring washers.

 

So do I. Loctite & new spring washers are completely OK.

By the way, the other good reason, apart from reduction in thread fatigue life, for using bolts into the cast iron block and studs into the aluminium gear casing is to avoid the risk of trying to put a 5/16" UNF bolt into a 5/16" UNC gearbox hole.

[Spider]

is to avoid the risk of trying to put a 5/16" UNF bolt into a 5/16" UNC gearbox hole.

 

 

 

Oh come on,,,,,, you're just not trying hard enough,,,,,, put your back in to it!

 

[Cooperman]

 

is to avoid the risk of trying to put a 5/16" UNF bolt into a 5/16" UNC gearbox hole.

 

 

 

Oh come on,,,,,, you're just not trying hard enough,,,,,, put your back in to it!

 

 

Been there, done that, then had to Heli-Coil     .