Former VWDieselParts.com Forum

Is it possible to replace the Crank pulley (harmonic balancer) of a 1.9TD AAZ with a TDI crank pulley? Mine isn't fairing so well and needs replaced. If I can upgrade to a better crank pulley then I'm all for it. Any help would be appreciated.

Thanks Todd.

IIRC it's doable but it takes machining your crank.

I've heard people talking about getting it done in place.

It's not the harmonic balancer/ crank pully that gets changed.
It's the crank sprocket for the timing belt.
The crank needs to have a flat spot machined onto one side.

The sprocket has a D at the end of the part number,.. and is shaped that way.

Here is what is involved in one of the in place processes:

http://www.vwdiesel.net/forum/index.php?topic=25135.0

Not to sound like a noob but mosy of my diesel experiance is on cat equipment. what would be the benefit of using a tdi pully? is this a turbo mod only or is it for NA engines as well???

The normal keyway is weak.
I've seen 2, 1.6TDs with a stripped out crank key,
usually a problem with 1.9s.

makes sense. I had a 8v 92 golf with digfiant II fuel sytem and while redoing th engine I found my keyway stripped. I had spares as I worked at a junk yard at the time. so just to clarfiy the TDI pully is the same size as 99% or so MK I/ MK II crank pully just the crank needs to be broached/machined to accept the pully? very cool.

reason for stripping is the cog belt doesn't slip like a V belt ... the engine pulses are very strong and beat the $%^& out of the sprocket locating pin..... loss of power and black smoke ... until it slips too much and the pistons kiss the valves.

the newer slot takes the abuse much better.

I am considering swapping my 1.6L IDI out of the caddy for a MTDI engine so i will not have to go thru the whole broaching process anyway.
If you know where i can get an engine cheap it would be helpful.

i am changing the timing belt on my aaz and notice rubber fatigue on the harmonic balancer. will a tdi harmonic fit the aaz??btw, my crank pulley looks great, no wear or movement to crank.

Yeah, the AHU/1Z harmonic balancer pulleys are interchangeable with the AAZ ones. I've noticed that the engine temps have been a little higher lately on my mTDI AHU. I just figured out that my harmonic balancer pulley has actually separated and the outer part will move a independently of the inner hub. It still looks fine, but a timing mark on the pulley does not land consistently with each crank rev.