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Plunger bolt removal

Submitted by andrew_wibmer on Sat, 31/12/2016
Forums
Light Twins

Having trouble removing the plunger bolt from the lh crancase, not sure if lh or rh thread, anyone know how best to deal with this. Would like to remove it as I want to try and flat the mating faces but the bolt protrudes past the face.

Submitted by peter_holland1 on Sun, 01/01/2017

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Andrew,

Can you tell us what year and model this lightweight is? I,m struggling to think of a plunger, as in cylindrical shape moving in/out or up/down, which crosses the crankcase joint faces.

Perhaps someone else can help, but I can only think of screws(which you must have removed), studs (which are all RH thread) or hollow dowels (which are push fit) which cross the crankcase joint faces.

Peter

Submitted by andrew_wibmer on Sun, 01/01/2017

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Previously peter_holland1 wrote:

Andrew,

Can you tell us what year and model this lightweight is? I,m struggling to think of a plunger, as in cylindrical shape moving in/out or up/down, which crosses the crankcase joint faces.

Perhaps someone else can help, but I can only think of screws(which you must have removed), studs (which are all RH thread) or hollow dowels (which are push fit) which cross the crankcase joint faces.

Peter

Hello Peter,

Sorry, Navigator 1960.

thanks for picking up the thread, the plunger bolt is behind the drive gear (Axle Sprocket) on the lh crankcase, it is part number 041335, housing the plunger which in turn presses against the cam plate in the gearbox. P42 in the "Twin Cylinder Manual For the Unaproachable" manual, P 150, item 27 in P.L. Garratt's book. I also have the "Maintenance Manual, publication 105/p" but no reference in this one as my gearbox is pre 10638.

I have tried a little heat and a little more pressure with my long arm socket set, but would not like to increase my current liabilities if you follow. This little gem is quite a challenge. :)

Andrew

Submitted by patrick_mullen on Mon, 02/01/2017

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Hello Andrew,

I know the bolt you are referring to - it is called the camplate plunger holder in the 1959 Maintenance Manual- but as far as I remember it is a normal right hand thread and there is no secret way to remove it. The Manual merely says "remove" and from my experience it has always removed without any problem. It sounds very possible that the bolt has seized in the alloy threads of the casing and if so it might be best to let it be unless someone can offer some better advice. Heat doesn't usually work and you end up with stripped threads if you use too much force.

Patrick.

Submitted by peter_holland1 on Mon, 02/01/2017

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Andrew,

I have just been out to the garage where I have a pair of bare early Jubilee crankase halves. I confirm Patrick is correct in saying the threads are right hand. Patrick has a wealth of experience on these models.

A large surface plate with a hole in it to flat the crankcase joint faces?

Peter

Submitted by andrew_wibmer on Mon, 02/01/2017

Permalink

Previously peter_holland1 wrote:

Andrew,

I have just been out to the garage where I have a pair of bare early Jubilee crankase halves. I confirm Patrick is correct in saying the threads are right hand. Patrick has a wealth of experience on these models.

A large surface plate with a hole in it to flat the crankcase joint faces?

Peter

Thank you both, I will give it one more nudge, were it not or the fact that the tube sits proud of the inner face, I would leave it, but I want to get the crank bearing out and would like to flat the mating face before I put it all back together.

 


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