[Vwdiesel] 1980 vw diesel timing belt broken when trying to start

[LBaird119 at aol.com]

  The first problem you're having is the Bentley manual is actually 
a reprint of the factory service manual, which presumes a basic 
automotive repair knowlege enough to get you hired as a tecnician 
(however minimal those requirements may be at some dealers!)
  TDC is when the valves are both closed so it can fire, that would 
mean that both cam lobes must be pointing as "away" from the 
lifters as possible at the time.  Deduction leads you to this and you 
find the correct of the two positions the engine can be at with the TDC 
mark on the flywheel in position.
  The (offset???) you mean slot? at the end of the cam can only be in 
one position an allow the cam lock to be inserted.  You may eyeball 
the slot or use a file or what have you to aid in checking position.  That 
slot is ONLY for checking position, not putting it there, holding the cam 
or anything else any of us have come up with!  ;-)
  To overcome loosening a bolt when turning the engine over (which actually 
doesn't happen all that often due to the proper torque of it) just put the 
car in 
3rd gear and push forward or back as needed.
  Yup, turning the engine over with the cam in the wrong place can break 
cams, lifters and bend valves.  However if you aren't doing the Neanderthal 
School of Mechanics version of turning the engine over you won't bend 
anything. 
If it doesn't want to go, it doesn't want to go, find out why rather than 
pushing, 
turning, beating harder!
  You've already deduced that the cam needs removed to be sure all valves 
are closed simultenously.  You don't need documentation for that, see problem 

#1 above.  :-)  You're doing the right thing in thinking!  :-)
 
  That all said (albeit just a tad cynically) you can check for a bent valve 
by 
turning the engine 90 degrees from TDC (in whichever direction it will allow) 

and then one cylinder at a time, turn the cam for TDC and measure 
clearance on the lifters.  If you have mega clearance on any of them, you 
have a bent valve holding the valve open, thus increasing the clearance 
between the lifter and the cam.
  Since it broke only while cranking you probably have a better than 50% 
chance that all is well and you only need to set the cam back to TDC #1, 
the crank on the TDC mark (it doesn't have to be on a correct stroke now 
as that pertains to its relationship to the cam) and the pump to the TDC 
position (there's a line on the pump side of the cogged gear that will line 
up with a casting mark in the top of the pump mount.  The pump will tend 
to rotate forward one cog beyond what it should be when the pin is installed.
  Something similar has happend to about all of us as well as the friends 
and family we've brought into the fold as well.
     Loren


In a message dated 6/22/2006 5:28:36 PM Pacific Standard Time, 
tolbert192 at hotmail.com writes:

> The manual discusses replacing timing belts and all the steps, tools ,etc 
> but not how
> to go about setting TDC, position of lobes on camshaft (intake versus 
> exhaust) at #1 or
> the position of the offset at the end of the camshaft.
> 
> Not clear on a couple of areas;
> 
> Since cylinder #1 is the one near the gears, (closest to the fender on the 
> passenger side) besides the TDC mark on the flywheel,
> should the offset of the camshaft be pointing down when at TDC?
> 
> Since the engine rotates clockwise when standing behind the timing mark 
> opening
> on the transaxle, then to start rotating the engine to get to TDC, the bolt 
> on the crankshaft sprocket must be turned counter-clockwise, which opens the 
> 
> door to loosen the crankshaft sprocket bolt. How does one overcome this 
> problem?
> 
> I also read that to rotate the engine, can cause damage to the camshaft, 
> bend valves, damage pistons.
> 
> The above implies that to reduce the amount of damage, the camshaft assembly 
> 
> should be removed, but I can find no documentation to that effect.
> 
> Please advise.
> Thanks.
> 
>