How Worried Would You Be? Rear Drum Backplate Bolts...

[TooMany2cvs 65]

FINALLY, we get near to putting the car back on it's wheels, on the rebuilt rear beam. On trying to bolt the backplates on, though, the threads were seriously tight - so I just ran a new bolt down the threads in the hub to clean them up. Worked just fine on seven, but on the last (upper rear, OS), it bound tight then the head sheared off the bolt! I've tried with moles, even grinding some flats into the thread to get better purchase, but it ain't coming out within the confines of the lousy space I'm working in.

 

So... what would you do?

Obviously, four is infinitely preferable. But three to hold the plate tight, with the stub of the fourth giving rotational stability? Would you drive it like that at all? Just sufficiently to get it to a better equipped workshop? Or indefinitely?

 

It's just a pikey-spec 1.1TU on 145/80s, so not exactly a track-day special...

[jord294 92]

Personally, I'd have run an m8 tap down the thread

[Anthony 1,002]

It should be fine with just three bolts, certainly in the short term.

 

Longer term I would want to drill it out and clean up the thread with a tap though given that it's not the easiest place to inspect for any signs of issues.

[Tom Fenton 1,541]

It will be OK for now but as said it warrants sorting out properly.

[TooMany2cvs 65]

Personally, I'd have run an m8 tap down the thread

So would I. If I had one handy...

[jackherer 543]

A proper tap is always best but you can turn a bolt into a tap of sorts.

 

e.g. http://www.instructables.com/id/Make-a-tap-from-a-bolt/