Hi guys

Wondered if someone might have some pointers for me on how to repair a
woodruff (are they called this in the US? Half-moon shaped disk) keyway on
a steel shaft.

Background:
Crankshaft is steel
Woodruff key is approx 5mm thick (3/8ths I think)

The alternator pulley bolt (on end of C/shaft) became loose and allowed the
pulley to chatter. Unfortunately this has allowed the key to chatter too &
has opened out the keyway slightly.

I took the pulley, preheated with a MAPP gas blowtorch, zapped it with the
MIG and allowed it to cool. I then spent a fair while with needle files
re-dressing the keyway. (Heavy pulley 110A 240V mig, C25 mix)

How might I be able to repair the crank? It will have to be done in situ.
Would hitting it with MAPP, MIG and careful use of a Dremmel suffice?
(I wondered about making a copper key to give me a non-stick surface to
weld up to.)

I really don't want to weld a key in permanently

I've used Quicksteel for the time being.

Thanks

The alternator pulley bolt (on end of C/shaft) became loose and allowed the
pulley to chatter. Unfortunately this has allowed the key to chatter too &
has opened out the keyway slightly.


Does this pulley mount on a taper? Or a straight shaft?

tight fit in the wallowed out slot in the crank, then narrow the top
part to fit the pulley Get a good trial fit, then use Loctite bearing
mount to secure the key in the crank and let it set before final
fitting the pulley
^^^^^^^^^^^^^^^^^^^^^

Mill a woodruff slot on the other side of the shaft?

How bout making a new key out of thicker stock, make the bottom part a
tight fit in the wallowed out slot in the crank, then narrow the top
part to fit the pulley Get a good trial fit, then use Loctite bearing
mount to secure the key in the crank and let it set before final
fitting the pulley..... Joel in Florida

Balders wrote:

Hi guys

Wondered if someone might have some pointers for me on how to repair a
woodruff (are they called this in the US? Half-moon shaped disk) keyway on
a steel shaft.

Background:
Crankshaft is steel
Woodruff key is approx 5mm thick (3/8ths I think)

The alternator pulley bolt (on end of C/shaft) became loose and allowed the
pulley to chatter. Unfortunately this has allowed the key to chatter too &
has opened out the keyway slightly.

I took the pulley, preheated with a MAPP gas blowtorch, zapped it with the
MIG and allowed it to cool. I then spent a fair while with needle files
re-dressing the keyway. (Heavy pulley 110A 240V mig, C25 mix)

How might I be able to repair the crank? It will have to be done in situ.
Would hitting it with MAPP, MIG and careful use of a Dremmel suffice?
(I wondered about making a copper key to give me a non-stick surface to
weld up to.)

I really don't want to weld a key in permanently

I've used Quicksteel for the time being.

Thanks :)

Mill a woodruff slot on the other side of the shaft?

GWE

Balders wrote:


The alternator pulley bolt (on end of C/shaft) became loose and allowed the
pulley to chatter. Unfortunately this has allowed the key to chatter too &
has opened out the keyway slightly.


Does this pulley mount on a taper? Or a straight shaft?

On Tue, 15 Apr 2008 10:45:48 -0700 (PDT), joelblatt@aol.com wrote:

How bout making a new key out of thicker stock, make the bottom part a
tight fit in the wallowed out slot in the crank, then narrow the top
part to fit the pulley Get a good trial fit, then use Loctite bearing
mount to secure the key in the crank and let it set before final
fitting the pulley..... Joel in Florida

That sounds like an idea, cheers

On Tue, 15 Apr 2008 17:26:44 GMT, Grant Erwin wrote:


Mill a woodruff slot on the other side of the shaft?

Too easy to get wrong, I'd also have to get someone to machine a keyway
into the pulley :'(

On Tue, 15 Apr 2008 15:27:18 -0400, Pete Snell wrote:

Does this pulley mount on a taper? Or a straight shaft?

Pete, it's a straight shaft.
It's actually a Subaru Impreza crank that's fitted to a vehicle. I've heard
of a fair few that have done this - not just Subarus.
I wonder why they don't machine a longer slot in the crank and insert a
square section longer key, say 1" - 1.5"

In article <jdwmcaz312iw$.1b8fo01aex92g.dlg@40tude.net>,
Balders <steve.bonnett@NObaesystems.com.SPAM> wrote:

On Tue, 15 Apr 2008 17:26:44 GMT, Grant Erwin wrote:


Mill a woodruff slot on the other side of the shaft?

Too easy to get wrong, I'd also have to get someone to machine a keyway
into the pulley :'(

Eh, beg pardon. Why? Wasn't it the shaft keyway that was enlarged? The
pulley won't care where it lines up with the key or am I missing
something?

Wow, That seems like a problem waiting to happen (guess it did...)
What about putting a pin in the face of the pulley and indexing it to a
hole in a thick washer, held by the nut? It would take some of the load
off the key.

On Tue, 15 Apr 2008 15:27:18 -0400, Pete Snell wrote:

Balders wrote:


The alternator pulley bolt (on end of C/shaft) became loose and allowed the
pulley to chatter. Unfortunately this has allowed the key to chatter too &
has opened out the keyway slightly.


Does this pulley mount on a taper? Or a straight shaft?

Pete, it's a straight shaft.
It's actually a Subaru Impreza crank that's fitted to a vehicle. I've heard
of a fair few that have done this - not just Subarus.
I wonder why they don't machine a longer slot in the crank and insert a
square section longer key, say 1" - 1.5"

If it all goes very pear shaped it would probably be easier to get a donor
engine. Well there's always the weld the pulley option first All for the
sake of a bolt and a 10p (20c) key!.