MG Car Repair: steering lock assembly - 1977 MGB, steering column lock, shear bolts

Question
QUESTION: In reading through some prior q & a's - I read this "Changing the ignition lock is a problem, because it is part of the steering lock mechanism, and the lock is bolted to the column using two 8mm bolts with shear heads.  To remove them you must drill the heads off".  So, after drilling them off & replacing the whole steering lock assembly, how are the bolts put in place? Is there anything else I should know before doing this? I am in 'uncharted waters' here. I have a 1977 MGB & cant wait to get it on the road at least 1 time before the snow starts here in Michigan. Thanks in advance for any help!!


MGB Steering Column Lo   ANSWER: Hi Rick.  The steering column lock is held in place with two shear bolts.  You must drill straight through the heads with a 3mm drill to a depth of about 8mm.  Then enlarge the hole with a 6mm drill, and the remains of the old head should come off on the drill bit.  Finally you extract the threaded parts, which usually come out easily.

The new lock will come complete with new shear bolts.  You just tighten the bolts up until the heads shear off.  I have attached a photo of a late MGB steering column lock so that you can see what I mean.

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QUESTION: Thanks - another if I may. I am replacing this as the starter odes nit dis engage when I start the car. Almost as if I am still turning the key all the way , like when starting. I 'guessed' that the part I am replacing will correct that. Possibly some spring inside just didn't operate like when it was newer.  Your thoughts, Please - Thank You again!

Answer
Hi Rick.  These locks do wear out and they do tend to stick instead of returning cleanly.  You may get away with replacing the electrical lock and short wiring loom.  These are available separately, and they contain the return spring.  The switch is the black plastic part held into the rear of the lock by a single grub screw.  You may have an earlier design of lock with a metal body, but the principle is the same.  

Before buying a new lock, remove the old lock and try spraying switch cleaning fluid into it.  It contains a lubricant which may buy you a few more years of usage.