Author Topic: AAZ crank pulley  (Read 3755 times)

January 27, 2017, 08:57:06 am

butch2000

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AAZ crank pulley
« on: January 27, 2017, 08:57:06 am »
How is the lower timing belt pulley mod done ? on the AAZ engine ? I have read about the damage that is possible , but unclear how to do the mod to prevent it



Reply #1February 07, 2017, 04:02:23 pm

retroloose

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Re: AAZ crank pulley
« Reply #1 on: February 07, 2017, 04:02:23 pm »
Hi Butch2000
I did the mod as my pulley was wobbling .The crankshaft end was all chattered. I ordered a crank milling tool from germany which took a few thou off the damaged crank and left it as new , great job!!!.

I ordered a new pulley and had the old pulley and new pulley drilled with two 3.8mm holes one either side of the bolt hole.  The new pulley was then drilled to 4.0mm .I bolted up the old pulley and used it as a guide with a 3.8mm bit i drilled into the crank .
I then drilled with a cordless very slowly with a 4mm bit into crank marking depth with tape on drill bit.

Then i put two steel dowels into the crankshaft with strong stud lock . Then the new pulley and a new bolt torqued with some blue threadlock.

Its as new 50k done since.

Reply #2February 28, 2017, 08:53:44 pm

libbydiesel

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Re: AAZ crank pulley
« Reply #2 on: February 28, 2017, 08:53:44 pm »
I prefer modifying the crank for the AHU d-shaped sprocket over the thought of pinning the sprocket for a couple reasons.  The main reason for my preference is that pinning the crank weakens the end of it and reduces the contact surface area (and friction) between the sprocket and the crank which is the primary force that keeps the sprocket from moving.  The other reason is the fact that if the sprocket ever needs to be replaced it will be more of a pain to have to modify the sprocket accurately to match the pinned crank.