Check out our companion site, The152.com, a premier Mk1 Volkswagen enthusiast community.

Translate This Site
Updates: What's new?

FAQ and Information

Tutorials & How-To's
     Tutorials Main Menu
     Transmission / Transaxle
     Engine Swaps
     Cosmetic / Trim

Technical Data

Mk1 OEM Paint Codes


Recalls & Defects
     Mk1 Rabbit / Caddy
     Mk1 Cabriolet
     Mk1 Jetta
     Mk1 Scirocco

5719293 visitors
since April 2008

[ Main Menu | Top Rated | Popular ]

Spun Crank Gear fix

Removing a stripped crank bolt, and repairing a spun crank gear

Quick premise: Crank bolt snapped getting up to speed on interstate. Pulley key wasted and crank Key slot partially boogered.

here is my fix pictorial:

- New Crank Pulley - VW (049-105-263-C)
- New Crank Bolt - VW (N-903-208-02)
- All New Belts
- Loctite (Stud and Bearing mount)
- 2 STD Roller Bearings (mid '70-'s Harley Sportster Trans Mainshaft)
- Brake Cleaner

Special Tools:
- Good set of Cobalt Drill bits
- #5 Easyout (5/16) with 19/32 drill bit (if needed)
- 1/16, 5/64, 9/64, 5/32 Cobalt drills (if not in set)
- Flywheel lock (if you have one
- Torque wrench
- Center Punch
- 14mm x 1.5 Thread Tap (if needed)

1- To make it easy I removed: the timing belt cover, the Serp tensioner, right from wheel, lower timing belt cover and inner fender well.

2- Using a center Punch I made a mark in the exact center of the broken Crank Bolt. I started with an 1/8 pilot drill bit and worked my way up to 19/32 to extract.

3- I then took the new crank Pulley on the drill press with a 1/16 drill bit and drilled one hole opposite keyway and all the way through (you can use 2 dowel pins if your crank is really trashed). I drilled the pilot hole so it would be in the center of the crank between the crank bolt hole and the outer edge of the crank (SEE Hind Sight Notes at bottom).

4- using the 1/16 drill bit and the crank pulley placed on the crank as a template, I drilled the hole in the crank to a depth of 1/2 the length of the dowel pin.

5- I then used the 5/64 drill bit in the same fashion, drilled all the way through the crank pulley (using it as a template) and then into the crank to the same depth as #4.

6- using the 9/64 drill I drilled the crank hole out (not using the pulley this time) to same depth as above (1/2 the length of the dowel). Go back and forth a few times to make the hole a tad bigger. You could probably go to the 5/32 drill for the crank only so the pin slides right in, but I wanted a tighter fit.

7- using the 9/64 drill I drilled the crank pulley hole 1/16" more then 1/2 the depth of the dowel from the Backside out. This will prevent the dowel from backing out and allow and easy way to drive the dowel in to the proper depth in the crank pulley.

8- Drive dowel pin(s) into crank pulley

9- Tap crank threads (14mm x 1.5) to clean them up if necessary. I needed to because when the bolt snapped, it slightly screwed up the first 2 threads. The bolt must screw in perfectly by hand to be able to torque properly.

10- use brake cleaner to clean everything. I then used a small amount of Loctite stud and bearing mount on the crank key slot, than mate surface of the crank pulley and crank and then used regular red (271) on the bolt.

11- Torqued to proper specs (66 Ft'Lbs + 1/2 Turn) using homemade flywheel lock.

Hind Sight notes:

1 - If your crank key slot is really bad you may want to use 2 dowels on either side of the crank (away from the old crank key slot).

2- If I had to re-do, I would probably have drilled the dowel(s) closer to the outside edge of the crank (further away from the crank bolt). This is because there is less shear force the further out you go from the cranks center point. I was worried about being too close to the end of the crank, but in reality, that's where the stock keyway is...

This is just me over analyzing things as it will likely never matter anyway..

Good luck and be patient if you try to do this as well. A broken drill bit in the crank will give you a world of hurt. (light pressures to drill and straight holes)



Write up courtesy of sdezego, of VWVortex.com

Contributed By: Sparky on Monday, November 17 [ Rate this tutorial ]

If you find any errors, or have additional information to add, please use our Feedback Form to send us a message,
so we can make this information as complete and as accurate as possible for other Mk1 enthusiasts. Thank you!
Tutorials ©
You need to install and/or activate the ImageBlock module in Gallery 2 before using this block
Road Trip: C2CtoH2O   
Wanna go on a crazy coast
to coast MK1 road trip?

Visit C2CttoH2o for more info.
Top 10 Links   
Anonymous -  01/07/2013
Anonymous -  08/26/2011
Anonymous -  04/08/2011
Anonymous -  01/17/2010
Anonymous -  11/29/2009
Anonymous -  08/19/2009
Anonymous -  02/03/2009
Lucky -  10/15/2008

Find our site useful?
Please consider making a small donation to keep this site ad free, and to show your support by contributing to the ongoing development of this resource. Thank you!
Site Info   
Hosted by:

Best viewed with:

Maintained with:
Link To Us
[ see more link options ]
This site is in no way associated with Volkswagen AG or Volkswagen of America. All site contents,
photos, graphics, text or otherwise, are Copyright MK1Vw.info & The152.com 2005-2009.
Contents are not to be copied, altered, or reproduced without written consent from the site owner.
All other logos, trademarks and comments are property of their respective owners.
PHP-Nuke Copyright 2005 by Francisco Burzi. | Powered by Nuke-Evolution.

This site is cached. Click here to update the cache.
[ Page Generation: 0.50 Seconds | Memory Usage: 8.9 MB | DB Queries: 33 ]

Find our site useful?
Please consider making a small donation to show your support.