5 -- Unbolt Front Cover Plate, so that you can remove Lube Lines going to Clutch Bearing Quill that supports that end of the Crankshaft.
6 -- Remove 6 Bolts holding the Clutch-Side Quill to Machine Frame. Quill is sealed to Frame with a "Sealastic" to prevent oil leaks. There are 2 Tapped holes in the Side of Quill, you can Screw 2 Bolts into these holes to force Quill away from Frame.
7 -- Bolt your Fork-Truck Chain to Clutch-Side Quill. Put Wood Blocks under Ram to Support it when Crankshaft is removed. With Workmen up on Machine Pushing & Guiding Crankshaft out, it should easily slide-out. Have Workmen Support the Brake-End as it comes out. Do Not let it Swing and Damage it's Bearing Journals!
8 -- Now you need a Really Good Machinist and Machine Shop!
--- Wrap Bearing Journals with Electrical Tape to Help Protect them from Scratches.
--- Chuck Crankshaft into a Good Lathe.
--- Face-Off Broken End as best you can.
--- For the FC1000 & FC1250 4" Crankshafts, Bore a Hole 2.500" Wide x 3.000"
Deep, with Straight Sides and a Smooth Finish. Carefully Measure your Hole.
Make a New Stub-Shaft .004" Wider than Hole, 2.504".
Note, the Exact Hole Size is Not Really Important, Just that New Stub Shaft is
.004" Larger in Diameter, so that you end up with a Good Interference Fit!
--- For FC750 3" Crankshafts, Bore a Hole 2.000" Wide x 3.000" Deep,
Make the Stub-Shaft .004" Wider than Hole, 2.004".
--- Use a Good Grade of Tool Steel. Strippit made their Crankshafts out of
"Maxel 3 1/2 RC 28-34" Steel, whatever that is.
--- Obtain a few Gallons of Liquid Nitrogen from a Welding Gas Supplier. It comes
in a Dewar Tank, and you need a Hose attached to it. Carefully Release Liquid
Nitrogen into a Small Cooler set onto the Floor. There will be a Lot of Fog!
--- Immerse Stub-Shaft into Liquid Nitrogen to Shrink it, about 20 Minutes or so.
--- Lay the End of Crankshaft on a Electric Hot-Plate for a Couple of Hours with a Tent
of Sheetmetal over it, to Heat and Expand it, to help insure Stub Shaft goes in all
the Way for a Good Fit.
We are trying to get it up to about 150 to 200 degrees Fahrenheit.
--- When Crankshaft is Hot, and Stub-Shaft is Cooled & No longer Bubbling,
Quickly Push It into your Bored Crankshaft Hole. Have a Small Hand Sledge
Hammer Handy & a Brass-Rod in case you need to Tap-It Home a Bit.
--- Stub-Shaft will Rapidly (in Seconds!) Expand into a Tight Interference fit
into Crankshaft, so be Quick!
--- Warm-Up Crankshaft a Bit, then Have a Good Certified Welder Weld a Deep
Bead around Stub-Shaft to the Crankshaft. Welding is Not Really Necessary
as you have Far More Gripped Area here, than what holds the Splin Hub,
but it seems to make People Feel Better if its Welded.
--- If Welded, Grind & Smooth & Polish your Welds, so you get No Stress Risers!
--- Chuck Crankshaft back into the Lathe.
Machine New Stub-End to Match the Old Broken-Off End.
--- Machine a Smooth Radius to the Brake Splin-Hub Area.
--- Brake Splin-Hub Part of the Stub-Shaft is Machined-Down to
2.0015" to 2.0020", This Is Very Important, as the Hub is Shrunk-On Here.
--- Mill In the Keyway Slot, and Snap-Ring Retaining Slot. We sometimes do not
do this, as if you do a Good job of Machining and Fitting, the Splin Hub will
Stay-Put OK without a Key & Snap-Ring to Hold It.
But you are Surly Safer if you do Machine-In & Install Key and Snap-Ring.
--- Strippit Typically (But Not Always) Machined the Area before Snap-Ring &
Hub to 1.985" to 1.995". This was to make it a Little Easier to Slide-On the New
Hot (Expanded) Brake Splin-Hub, But is Not Really Necessary.
Some were made with the 2.0015 to 2.002" Diameter all the way to the End.
We like 2.0015 to 2.002 Shaft Diameter all the way to the End,
as it is Better to Fit Our Nylon Timing-Hub on to.
--- If you are going to use the Old Aluminum Timing Disk,
Machine End of the Shaft to Just like Your Old Shaft End.
--- If you want to use a Nylon Timing-Hub Retrofit like Ours, I Would Make
New Shaft 1" Longer, with the End Drilled & Tapped in Center for a 1/2" Bolt.
This Extra Length gives us More Room to Fit Nylon Timing-Hub and Sensor
Bracket at End of Shaft, and to have Clearance for Brake Movement.
--- Note! Your Machinist may Cry about not being able to Machine Crankshaft with
Clutch-Side Quill & Bearing Still-On.
It Can Be Done, as the Photo Below will Show, though it is certainly more Difficult!
He & You will have to Make Sure Inside-Surface of the Quill, and the Surface of Crankshaft Eccentric facings it, Does Not Rub or Gall or Wear against each other while being Machined or Transported! These are "End-Bearing" Surfaces that control the End-Play on Crankshaft, and Must Not Be Damaged!
On the Other Side of Quill, Make sure Seal is Not Damaged by Hitting Clutch Splin Hub
or you will have an Large Oil Leak when its all put back together!
The Alterative is to Cut-off Clutch Splin-Hub so that you can remove Quill. This is Really the Best Way to do this Job. Then, of course, you will have to Buy and Install a New Clutch Splin Hub on Crankshaft when Reinstalling into Machine. Your Choice.