datsun-roadsters
[Top] [All Lists]

Re: Slipped timing chain on U-20?

To: <Datsun-roadsters@autox.team.net>
Subject: Re: Slipped timing chain on U-20?
From: "Andy Cost" <andycost@worldnet.att.net>
Date: Sun, 9 Jul 2000 19:42:21 -0500
I had a screw come loose in the distributor at an autocross.  It sputtered
and backfired and then would not start.  The screw got jammed in the points.
I doubt your chain skipped.  To check it crank the motor by hand or by
rolling the car in gear until the timing mark on the crank gear is at TDC
and the rotor is pointed toward the front of the motor..  At this point the
cam key(screw) should be at the 3:00 position.  If it jumped a tooth the
screw will be more like 2:30 or 3:30(A.M. or P.M your choice).
NT
----- Original Message -----
From: <MMccaf8697@aol.com>
To: <datsun-roadsters-digest@autox.team.net>
Sent: Sunday, July 09, 2000 11:02 AM
Subject: Fwd: Slipped timing chain on U-20?


>
> --part1_25.810df87.2699fc0f_boundary
>
> In a message dated 07/08/2000 11:40:57 PM Mountain Daylight Time,
MMccaf8697
> writes:
>
> << Fellow roadsterites:  Troubles began on a drive to a wedding tonight
(not
> mine).  Upon starting from a stop sign on a steep incline, some wheelspin
was
> experienced, and when traction was gained, engine stalled. No restart,
only
> some weak backfiring.  Engine seems to have some compression or load on
> starter.  Prior to this there was some timing chain rattle at low idle
(about
> 800-900 rpm).  Engine is reportedly rebuilt about 3000 miles ago and
previous
> inspection revealed newer appearing timing chain, and top gear (removal of
> valve cover only).  Timing chain tension appears to have several washers
to
> shim shoe outward, but otherwise appears new(er).  How can I quickly check
> for timing gear jump?  Is jumping most likely at upper cam gear or
jackshaft
> gear? (I am not looking forward to removal of front cover).  Assuming
chain
> has jumped at top gear, can I simply set piston #1 at TDC and reposition
cam
> and cam gear to bright link and dimple on cam gear?  Advice on diagnosing
> this and how to proceed would be greatly appreciated.
>  Mark McCafferty
>  67 1600 with U-20 and 5speed
>  WyCROC >>
>
>
> --part1_25.810df87.2699fc0f_boundary
> Content-Disposition: inline
>
> Return-path: <MMccaf8697@aol.com>
> From: MMccaf8697@aol.com
> Full-name: MMccaf8697
> Message-ID: <36.85a6c19.26996a69@aol.com>
> Date: Sun, 9 Jul 2000 01:40:57 EDT
> Subject: Re: Slipped timing chain on U-20?
> To: -datsun-roadsters-digest@autox.team.net
> MIME-Version: 1.0
> X-Mailer: AOL 5.0 for Windows sub 109
>
> Fellow roadsterites:  Troubles began on a drive to a wedding tonight (not
> mine).  Upon starting from a stop sign on a steep incline, some wheelspin
was
> experienced, and when traction was gained, engine stalled. No restart,
only
> some weak backfiring.  Engine seems to have some compression or load on
> starter.  Prior to this there was some timing chain rattle at low idle
(about
> 800-900 rpm).  Engine is reportedly rebuilt about 3000 miles ago and
previous
> inspection revealed newer appearing timing chain, and top gear (removal of
> valve cover only).  Timing chain tension appears to have several washers
to
> shim shoe outward, but otherwise appears new(er).  How can I quickly check
> for timing gear jump?  Is jumping most likely at upper cam gear or
jackshaft
> gear? (I am not looking forward to removal of front cover).  Assuming
chain
> has jumped at top gear, can I simply set piston #1 at TDC and reposition
cam
> and cam gear to bright link and dimple on cam gear?  Advice on diagnosing
> this and how to proceed would be greatly appreciated.
> Mark McCafferty
> 67 1600 with U-20 and 5speed
> WyCROC
>
> --part1_25.810df87.2699fc0f_boundary--
>


<Prev in Thread] Current Thread [Next in Thread>