I have had quite a few requests for information regarding the repair of 1.9TD cranks that have suffered from the dreaded "crank pulley syndrome". I had the opportunity over the holidays to document the procedure as is was performed on board member "g-spec's" crank. His crank was not badly damaged but the procedure is the same for every crank I do. This is not a commercial post. It is for information only. While I do perform this procedure for money it is really not a high profit venture. I encourage anyone with the equipment and the know-how to do it themselves. I will gladly provide you with any information that you cannot glean from this post. Andy2 also has a unique setup that can modify a crank with it installed in the engine. If yours isn't badly tore up this might be the way to go.

The procedure starts with a thorough cleaning of the crank nose with a wire wheel. The old keyway extends into the seal area on the crank nose and will be covered later by a sleeve so it gets welded first with a TIG welder and 4130cr/mo filler rod. Note the masking tape over the journals. Weld spatter, though minimal with the TIG, will destroy a journal. Masking tape is cheap insurance.  



This area is then carefully filed smooth with the crank surface and an aluminum sleeve is pressed on. This is partly to protect the seal surface during the welding and partly to size the crank nose for a bearing that I use to hold the crank during the subsequent machining.



The remaining welding is then done. I take frequent breaks to avoid overheating the crank. I like to keep the temp of the first main bearing journal below 300ºF to avoid annealing it. I'm not sure if the crank is actually surface hardened on every journal, but I don't take the chance. After welding I press on a 6007 bearing for the jaws of the lathe steady rest to bear against. I could allow them to bear directly on the main journal but I have had the brass pads seize to shafts before and it makes a mess... This is method is safer, though a bit more time consuming.



The crank is mounted in the lathe using a steady rest on the bearing. The first operation is to machine the face back to the stock dimension. I cut the face slightly concave (~0.5º) to insure that the pulley tightens at the outer edge first and cannot rock on the face. A small boring bar is used to recut the centre hole taper to 60º so that a live centre can be used for the remaining machining.



The steady rest and bearing are removed and a live center is used to support the crank while the OD is turned. I make this diameter a .001-.0015" interference fit. I measure the pulley that will be used as they tend to vary a bit in bore size. I don't have any pics of this part but the setup is pretty basic. I also neglected to take any pics of the flat being cut on the crank nose but its also quite simple. The crank is held by the 2 machined areas on the first bobweight in a vise on a bridgeport milling machine. The other end is supported by an adjustable screw jack. Once leveled using a dial indicator on the seal surface, I cut the flat. The flat is also made a slight interference fit.

And here is the finished product.



The pulley is a tight press fit and must be drawn onto the crank nose using the bolt. Make sure to torque the bolt to spec (66ft/lbs +90º). Adding the clutch alternator pulley from the TDI is also helpful, it takes all of the vibration out of the accessory drive. I'd install it just for the increase in serpentine belt life if nothing else. It has come to my attention that the clutch pulley may not fit the 70A versions of the TD alternator properly, more info is pending... It will fit the 90A unit used on AC equipped models just fine. Make sure your harmonic balancer runs true, they often don't. Replace it with the new style one (028 105 243T, available from autohaus arizona for cheap) if it's crooked.

Hopefully this will reduce my PM and e-mail traffic a little and answer some of the repeat questions that get posted here.

Anyone in the Edmonton area can do this for me? Or can refer me?

My crank is soo bad the bolt fell out in the middle of the road as i was driving a couple weeks ago. The end of the crank is now a bit damaged and isn't a tight fit for the pulley, there is loosness there.

Please help

Anyone in the Edmonton area can do this for me? Or can refer me?

Call your local automotive machine shop, they should be equipped to perform the repair. Show them these pics if you like. You'll probably have to remove the crank (or have it removed) yourself though.

I have them in stock with the new bolt for $49 CAD.

Customs is gonan be next to nill for something this size, plus its not worth much but if you find a good source down there than good on ya!

028 105 263 D

There ya go man

For some reason the pictures disappeared so I ask QuickTD for the pictures.



Weld

Sleeve

Bearing

Turn

Done.


This what he has to say...

Here you go. "weld" shows the beginning of the welding process. "sleeve" shows the finished welding and the sleeve pressed on ready to recieve the bearing I use in the lathe steady-rest. "bearing" shows the bearing in place. "Turn" shows the setup for re-machining the face and center hole. Once this is completed I remove the steady and use a live center to support the crank for the remaining machining. The flat is cut in a regular bridgeport type milling machine gripping the crank by the 2 flats on the front bobweight.
 
Later,