STRIPPING . . . . . an 850 MK3 engine

click said:

Thanks guys for your suggestions. I've been hitting the sprocket and the bolt which tightens the puller, at this stage I'm afraid I'll blow the crank out the other side of the cases :roll:

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Have you tried doing it the Mick Hemmings way?
In his video, he recommends drawing the sprocket off by tightening the two smaller extractor bolts in preference to the centre bolt.

L.A.B that is almost insulting advice to read, tighten everything 1st, sheeze. You will age fast into an old pro by the time you get through this horrific task. In cases like this you screw down all the puller bolts to about max bolt stretch and thread shearing and puller fracturing. click, only a few old pros have run into our level of stuck up so you will have to toughen up extra over the parts frustration for the experts attitude you are inept mechanic when their ordinary stuck up advice fails, must be your fault of course not theirs, ugh. It can take many cycles of max efforts of extremes of thermal contrast, penetrating fluid and brutalness to crack this Gordian Knot. Do try the air impact on the main bolt at some point before torching off makes best sense.

I've thought of liquid N2 dip to try to scatter sprocket apart.

One thing to consider is the puller thread pitch, cause threads need a lot more grunt to get the same force as a finer thread , 5/8 bsf or 16mm x1,5 tread is good. 3/8 unc...BAD!!!

L.A.B. said:

click said:

Thanks guys for your suggestions. I've been hitting the sprocket and the bolt which tightens the puller, at this stage I'm afraid I'll blow the crank out the other side of the cases :roll:

Click to expand...

Have you tried doing it the Mick Hemmings way?
In his video, he recommends drawing the sprocket off by tightening the two smaller extractor bolts in preference to the centre bolt.

Click to expand...

Mick also said I believe that the sprocket should be removed before the head and barrels, same with the exhausts. I think it's procedure and preparation that makes life easier, but as it's a parts exercise it may not matter the same.
J
Oh and that's why I love my mallets and hammers.

hobot said:

L.A.B that is almost insulting advice to read, tighten everything 1st, sheeze. You will age fast into an old pro by the time you get through this horrific task. In cases like this you screw down all the puller bolts to about max bolt stretch and thread shearing and puller fracturing. click, only a few old pros have run into our level of stuck up so you will have to toughen up extra over the parts frustration for the experts attitude you are inept mechanic when their ordinary stuck up advice fails, must be your fault of course not theirs, ugh. It can take many cycles of max efforts of extremes of thermal contrast, penetrating fluid and brutalness to crack this Gordian Knot. Do try the air impact on the main bolt at some point before torching off makes best sense.

I've thought of liquid N2 dip to try to scatter sprocket apart.

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Now now hotbot, behave :mrgreen: , everybody is just trying to help, which I'm very thankful for :lol:

I understand that tightening the smaller bolts will have a slightly different effect than tightening the bigger middle one, and who am I to argue with Mick Hemmings or L.A.B. for that matter :roll:

Once again many many thanks for all the useful advice

OK, today I tried:

Packing the area with ice and then heating the sprocket (only have bottled gas flame) but alas no movement!



I had a choice of persuasion devices:




Guess which one did the trick :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen:



I think if the engine was more precious to me I would not have used the sledge hammer, but three short, sharp, 'taps' and off it popped :mrgreen:

More Anon

Just re-read a post above from hotbot:

"The group mind focus does help, somehow alters reality and quantum entanglements magically to release impossible fusions like yours."

Philosophy, Sociology, Physics and Poetry all rolled into one :mrgreen: :mrgreen:

Ah so grasshopper, a 3# sledge is my primary tool on many Commando tasks. All of us can rest easier now. If something don't come off with 1st initial ordinary effort I force nothing but get out ice/heat and big hammer, like the old pro you are now. Keep in mind the collective power of group mental focusing as may need it again on next task to split the cases. pre-Peels were torqued to jam the two dowel pins terrifically... DS case twisted on the TS case and jammed just as tight once tested together empty with crank finally freed for more daze to get back apart and figure out why...

click said:

and who am I to argue with Mick Hemmings or L.A.B. for that matter :roll:

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Nothing to argue with me about, I was just relaying the information from 'The Man' himself. :wink: :wink: (He also said heating the sprocket isn't necessary but don't tell hobot or he might blow a gasket!) :mrgreen:

click said:

I think if the engine was more precious to me I would not have used the sledge hammer, but three short, sharp, 'taps' and off it popped

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Well. if you'd been tippy-tapping at it with the other toffee hammers, it's no wonder it wouldn't come off! :roll: :lol:

LAB,
It's imposible to instruct someone over the internet how hard to hit some thing...after many years it comes naturaly..

hobot said:

Ah so grasshopper, a 3# sledge is my primary tool on many Commando tasks. All of us can rest easier now. If something don't come off with 1st initial ordinary effort I force nothing but get out ice/heat and big hammer, like the old pro you are now. Keep in mind the collective power of group mental focusing as may need it again on next task to split the cases. pre-Peels were torqued to jam the two dowel pins terrifically... DS case twisted on the TS case and jammed just as tight once tested together empty with crank finally freed for more daze to get back apart and figure out why...

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Nothing like some extra "force"

click said:

auldblue said:

Click

A wee impact wrench at the local garage might be worth a shot!

J

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Thanks, I might try that later after I use some TNT :mrgreen:

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HOPE YOU DIDNT DO THIS.

YUP THE LONG TAPERED PUNCH AND THE BIG SLEDGE HAMMER TRICK. yOU JUST HAVE TO SHOCK THE PULLEY AND TELL IT WHO,S THE BOSS.

kerinorton said:

click said:

auldblue said:

Click

A wee impact wrench at the local garage might be worth a shot!

J

Click to expand...

Thanks, I might try that later after I use some TNT :mrgreen:

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HOPE YOU DIDNT DO THIS.

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NO, thought better of it, could only end in tears . . . . . . . mine :lol:

olChris said:

hobot said:

Ah so grasshopper, a 3# sledge is my primary tool on many Commando tasks. All of us can rest easier now. If something don't come off with 1st initial ordinary effort I force nothing but get out ice/heat and big hammer, like the old pro you are now. Keep in mind the collective power of group mental focusing as may need it again on next task to split the cases. pre-Peels were torqued to jam the two dowel pins terrifically... DS case twisted on the TS case and jammed just as tight once tested together empty with crank finally freed for more daze to get back apart and figure out why...

Click to expand...

Nothing like some extra "force"

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hmmmm a lightsaber, could come in useful for splitting the crankcases!

L.A.B. said:

click said:

and who am I to argue with Mick Hemmings or L.A.B. for that matter :roll:

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Nothing to argue with me about, I was just relaying the information from 'The Man' himself. :wink: :wink: (He also said heating the sprocket isn't necessary but don't tell hobot or he might blow a gasket!) :mrgreen:

click said:

I think if the engine was more precious to me I would not have used the sledge hammer, but three short, sharp, 'taps' and off it popped

Click to expand...

Well. if you'd been tippy-tapping at it with the other toffee hammers, it's no wonder it wouldn't come off! :roll: :lol:

Click to expand...

Where do I get these 'toffee hammers', I'm partial to a bit of toffee :mrgreen: :mrgreen:

john robert bould said:

LAB,
It's imposible to instruct someone over the internet how hard to hit some thing...after many years it comes naturaly..

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I think, in the interest of the forum, you should go off for a few weeks and figure out how you explain to guys like me how hard to hit something a bit like:

Enough to crack an egg
Enough to dent a car
Enough to release the front crankshaft sprocket on a Norton Commando!!

pre-Peel swing arm spindle took a week to pull and hammer, with repeated repairs to the big chisel to crush rust flakes to nano dust then plow grooves in the hardened spindle layer length while dragging spindles worn lips scraping out bronze bush canals. Broke hand bones through very thick welders glove as I got slap happy sloppy from shell shocks. Trixie Combat spindle stored near river front New Orleans didn't budge with a puller made out of truck shock strut and 3lb sledge, so gave up fast to avoid body injury again. I torched off swing arm and took to dozer shop with 30,000 PSI press. Only took like 24,000 PSI to get it moving then 18,000 most the way then last inch about 12,000 PSI. I could of done it as I did pre-Peel, like Africans did on basket ball size metal meteor used as anvil over 30,000 years to mushroom its top over and fold back under one smack at a time. Trixie's very well blocked-backed up cradle still looked like deforming plastic object but sprung back enough to use again work hardened better than ever. These level stuck events prevents me from ever taking on another restoration no matter the bargain. I've got a useful tractor waiting instead. So click's post brings Commando PTSD flash backs.

click said:

Where do I get these 'toffee hammers', I'm partial to a bit of toffee :mrgreen: :mrgreen:

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Save a piece for me!
http://www.treasureislandsweets.co.uk/p ... -Pack.html

(PS, I wasn't being entirely serious about using the sledgehammer, the lump hammer should have been enough)

Its done now so no issue but if you ever try again its also a good idea to run a nut on the threads on the crank to prevent damage. Then the spacer to protect the crank lands on both the nut and the end of the crank.

Very especially important when pulling sprockets off smaller diameter shafts - like magnetos :-( (I was only 19!)