4 replies to this topic

[Mito]

I'm in the middle of putting a duplex timing chain on my 998 a+ engine ( I know it's overkill).

New woodruff key, new duplex sprocket.

The crank sprocket will slide over the crank easily enough without the Woodruff let in situ so it must be the new Woodruff key causing the restriction.

I've tried one of the other new woodruff keys in the sprocket and, whilst tight, it does fit in the groove.

Using a rubber mallet, I can get the sprocket on almost to the end of the Woodruff key, probably 2-3mm left to go to the end of the Woodruff key, though plenty to go before is fully home.

How easy should it be to get the crank sprocket on? Do I just need to apply more force or should relatively gentle taps with the river mallet be sufficient? Or do I need to do something with the woodruff key?

The engine is still in the car so can't get much on it.

Edited by Mito, 02 September 2023 - 10:08 AM.

[nicklouse]

Seems the key needs tidying up. How does it fit in the sprocket out of the crank.

[Ethel]

It can be tricky, some things you could try...

 

Check the key will slide through the slot in the sprocket first.

 

Rub the edges (corners) on the key with a file or wet 'n dry to deburr them.

 

Fit the sprocket so it's just covering the outboard end of the key, then tap the inboard edge in to the slot in the crank with a drift / socket extension bar...

[Icey]

Just had similar, keyway needed dressing and deburring, and I used a deburring tool to put a slight chamfer on the keyway of the sprocket.
I also used an India stone to lightly dress the woodruff key as well as it had a couple of high spots from being knocked in/out a couple of times.

Just a fiddly, faffy job, nothing major wrong most of the time.

Edited by Icey, 02 September 2023 - 11:26 AM.

[Mito]

Thanks for the suggestions. I run one of the spare Woodruff keys through the sprocket key way and there's definitely a restriction part way down.

I don't have a deburring tool so I opted for running a file through the key way to clean it up. It's still tight but it will go fully home now and I can get it over the Woodruff key without the mallet, just need the mallet to get it fully home.