Would anyone have any pics of what an AAZ crank nose is supposed to look like? I think mine is royally buggered.
Same as TDI now
Stock, it should be a clean looking keyway with sharp edges but it doesn't hold. This is the fix. The new sprocket is TDI
Some have had success doing this while it's still in the block - do a bit of searching on here and you'll get tons of info.
Ahhhh, that's what I needed. Thanks !
None of the pictures here show a stock crank nose.
Also, the D shape mod can still fail. TDIs which have this stock are failing.
None of the pictures here show a stock crank nose.
Also, the D shape mod can still fail. TDIs which have this stock are failing.
You gotta be kidding - How does the TDI design fail?
My stock crank before I put the D on it looked just like this possibly without the small flats (if I recall). It hadn't moved but as I was adding HP and due to several recommendations from vets on this site, I welded it up, machined it and bought a TDI sprocket.
Wish I had taken pics before I re-did it.
It shouldn't have any flats. It's identical to a 1.6 crank nose.
You need a clutched alternator pulley if you are running a serpentine belt.
I'm very interested to know how the "D" sprocket fix is failing.
My guess is that some folks are using the TTY bolt twice, not torquing to spec or a bad weld/fit.
Any info appreciated.
Here's a shot of my undamaged sprocket (engine 1.9 AAZ TD, origin unknown) - your crank nose should be the opposite of this
The width of the "key" is 7.93 mm, the bore measures 30.91 mm and the bore depth measures 5.98 mm.
It wasn't loose nor did it show any signs of failure. I run a "V" belt to a 60 amp alternator which possibly absorbs the inertia of the spinning alternator. As has been pointed out, if you have a serpentine belt, a clutched alternator pulley is recommended to keep the inertia of the alternator from hammering the sprocket loose over time. A serpentine belt has much less forgiveness of that energy.
I have personally seen one failed TDI sprocket interface. The alt pulley was seized and no longer free-wheeled.
I have personally seen one failed TDI sprocket interface. The alt pulley was seized and no longer free-wheeled.
Thats why I'm stickin with the V-belt
