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Author Topic: Crank Pulley Lock Tab Washer  (Read 2365 times)

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Crank Pulley Lock Tab Washer
« on: August 15, 2017, 09:40:10 PM »
Q:   My name is Doug Duncan and I am a longtime British car owner.  Have enjoyed watching your videos on YouTube for some time.  Used to live in California but now retired and living in Bretagne in western France.

My wife and I have owned a '68 MGB-GT since 1969 which I am restoring at the moment.  The first MG I restored was a 1960 MGA in the 70's.  Still have a 1964 Land Rover 88 series IIa station wagon (restored in the 80's), which was the first car we bought after we were married in 1968. Also have a 61 Morris Minor Traveller I restored in the  80's, just like another one I had when I was in college.  Restored a 1965 Jaguar Mk II in the 90's also.  As you can see I have a bad case of the disease.

The reason I am writing is to get your confirmation of a parts disagreement I am having with Moss in England.  The disagreement is over the front crank pulley lock tab washer they supplied for my '68 GT. The photo below shows the original that came off the car on the left and the replacement they shipped on the right.  I tried to explain to them that the washer they are selling has no tab to lock into the keyway on the pulley so in effect the washer they supply acts as a plain washer.  The notch in the washer is useless as there is no key for it to slide over. They tell me that they have sold this washer for years and never had a complaint. I believe the same one is sold in the U.S. by Moss. The one they shipped was rusty (as you know it rains a lot in the U.K.) as you can see and also has a little paint on it where I tried it thinking I was missing something.

Would appreciate your opinion on the subject. I realize you are busy and you have mentioned you don't check emails a lot.

All the best and keep up the good work.

Doug Duncan


  • AMGBA Club Tech Staff
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    • University Motors
Re: Crank Pulley Lock Tab Washer
« Reply #1 on: August 15, 2017, 09:57:55 PM »
A:    I understand why you're in this quandary.   Often someone will tell me, "I put it together the way it came apart."  That is a good rule to follow -- as long as the previous mechanic put it together correctly.  You have a picture of two different parts here.  The one on the left is the locktab from the camshaft; the one on the right is for the front crankshaft pulley.   But "WAIT" you say -- "How can the one on the right lock if there's no tab?"

Good question.

Examine the front crank pulley.  You'll find a divot, a machined relief opposite the keyway.  Once you fit the locktab under the front crank bolt (and it's easy to get it misplaced because of the diameters), use a punch and drive the locktab into that relief.  Then, use you long screwdriver or chisel to fold the locktab over the nut on one of the available faces (obviously not the same one you just drove into the pulley).  I usually use some blue Locktite in this application.

Further questions might be:  How does one get this bolt tight?  An air ratchet gun is the best.  If that's not available, use a breaker bar with your 1 5/16" socket, tighten the nut until the engine begins to turn.  Now you can have your associate sit in the driver's seat and apply the brakes with the gearbox in reverse, but one can only get the engine so tight.  So get it as tight as you can and smack the breaker bar with a hammer (the same technique as used with the air ratchet). 
The next question is:  How does one get this bolt loose?  Again, use that breaker bar and a 1 5/16" socket.  Place the breaker bar on the LEFT inner fender (USA driver's side), port side, near side.  You hold the breaker bar and your associate hits the starter (have the coil disconnected!).  The bolt will turn out effortlessly.  For Christ's sake do NOT put the breaker bar on the right side, starboard side, off side or you'll kill yourself. 

Hope this helps!
John Twist
John H Twist
University Motors Online
100 East Beltline Avenue SE
Grand Rapids, MI  49506


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