[ProteinDrinker]

Hey guys I recently bought an aftermarket flywheel for my Sierra, it does not have a hole for the crank dowel to go into, nor does it have any timing markings along the side.

Does the Sierra flywheel need to be fitted in any particular way to maintain correct timing or can you just bolt it straight on?

[Andygoodbloke]

Check the diameter if you have not already,
If a centre hole is missing - put one in after measuring twice. I would recommend doing this on a metal lathe to get the centre perfect, if off it will ruin the new flywheel. being off centre. If worried about the markings copy the markings by getting paper or thin cardboard and make a template and transfer onto the new flywheel. Before taking the old flywheel off set a mark to line up to when putting the new one back on so the flywheel will line up to the mark on the backing plate or block

Are you going lighter or heavier with the new flywheel as the heavier will make the engine harder to rev but will hold the revs more once there - has some good points for 4wding, lighter will make it easier to rev but will kill the momentum easier if on slopes or in thick mud etc.

Let us know how it turns out

Cheers Andy

[Boggomobile]

Hi All,

ProteinDrinker wrote:

Hey guys I recently bought an aftermarket flywheel for my Sierra, it does not have a hole for the crank dowel to go into, nor does it have any timing markings along the side.

Does the Sierra flywheel need to be fitted in any particular way to maintain correct timing or can you just bolt it straight on?

Hopefully I can make more sense than our Kiwi friend?

The dowel is not on centre!

Some Sierra's have the timing marks on the flywheel and some are on the crank pulley. If yours is on the crank pulley, you can simply place your old flywheel accurately aligning the mounting holes on top of the new flywheel. Then drill through in a drill press, there is some room for error as the flywheel mounts on a spigot. The dowel is for alignment so timing marks are correct.

The same goes for the timing marks as they can be transferred and stamped in.

Hope this helps