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Crank nose too long!!

Posted: Tue Nov 12, 2013 8:41 am
by GRIMACE
Got this up on a few forums now but figure the more the merrier as I need to rectify this in time for a trip to Coffs in two weeks!

My scenario. I have a 4.6 block with a 3.5 v belt front cover configuration that uses some 3.9 pulleys/ancillaries.
Last night I was stripping the front end to replace the 3.5 v belt front cover with a second 3.9 v belt front cover as the 3.5 front had a crack at base around the Distributor driven oil pump gears and had been leaking since it went in.

I was on a roll, but discovered something odd that was seemingly never picked up when the engine was assembled.
The crank pulley was floating on the crank, it had almost an inch of movement (in and out).
At first I thought the crank pulley bolt had come loose but when I cleaned it all up removed it and replaced and checked I was presented with this;
Image

And this is the bolt and spacer that was holding this all together;
Image

So put simply the 4.6 crank nose is too long???
I can not believe the crank nose and key as well as the pulley have survived this.

If any one can shed some light on how I can rectify this dilemma it would be much appreciated.
Please also keep in mind that I have a complete serpentine belt front end that I can utilise if it will solve the issue? I would actually prefer to swap it all back to serp belt, but so far have not been able to find the info on what is and is not required.

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 8:45 am
by mkpatrol
Spacer in behind the pulley if the belt alignment ans sealing surface on the front seal will allow.

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 9:08 am
by GRIMACE
mkpatrol wrote:Spacer in behind the pulley if the belt alignment ans sealing surface on the front seal will allow.
Nope. Just double checked this. I have toyed with the option of a sleeve spacer that goes over the crank and allows the crank bolt washer to clamp down on the inner edge of the pulley.

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 9:26 am
by mkpatrol
That is your other option.

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 9:33 am
by GRIMACE
mkpatrol wrote:That is your other option.
Yeah got a couple of suggestions on pirate and Aulro seems this is quiet common.

From Aulro;
bee utey;2026038 wrote:All 4.6 conversions to distributor style front covers need a spacer ring on the front of the crank to allow for the extra crankshaft length. A suitable piece of steel pipe could be machined up, or a segment of an old front pulley. Shame on your engine builder for not knowing this!

Example:

http://www.thewedgeshopstore.com/produc ... 6-4.6.html" onclick="window.open(this.href);return false; - Crank Spacer 4.0 & 4.6 - The Wedge Shop

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 9:36 am
by GRIMACE
Looking at this a little bit more, I assume the spacer has the keyway groove?
Cant see any in that image from the wedge shop?

If you look at my first post the image clearly show the keyway also protrudes past the pulley, so any spacer is going to need to be keyed to suit?


IGNORE THE ABOVE!
I just realised the keyway does not protrude past the end face of the pulley. So that spacer or any simple non keyed spacer will work.

Re: Crank nose too long!!

Posted: Tue Nov 12, 2013 10:25 am
by mkpatrol
Yep the spacer will need to be keyed to suit, if it doesnt it you will risk it coming loose. Also, wthe the extra spacer you will need to make sure its tight. When I was in the trade I saw the issue of cranks pulleys that were not interferance fits coming loose a number of times.

One thing I would look at if I were you, because you are adding stuff thats not supposed to be there use shaft fit and locktite on the pulley and the bolt.

My MK, I bought it with a loose pulley, it had worn the nose of the crank, the pulley and the keyway was munted. I cleaned up the keyway and made a new wider one, made the groove in the pulley larger for the larger keyway and used heaps of shaft fit & locktite. It was uber bodgey but for a truck that was worth 1000 bucks it wanst worth pulling the engine and fixing it.

It worked, for the first couple of services I had to tension the nut on the crank but iot settled in and I didnt tougch it until I sold it a couple of years later.

I wouldnt have done that fix on a customers car though.