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+--- Thread: Timing marks illegible (/showthread.php?tid=6464)
Timing marks illegible - eggtrucks - 08-06-2020
How do i go about doing overhead when the timing marks arent visible any more? Cm 2350
RE: Timing marks illegible - Waterloo - 08-06-2020
Start with a wire brush and sandpaper... You will need to be able to bar the motor to get to the actual timing marks. Once clean, I would paint with something to mark them for the next time. If the truck has over 500,000 miles, Cummins recommends changing out the damper, as the internal viscous fluid that handles the balancing act hardens over time. So, not knowing how many miles on your truck... A damper runs around $650 to $700 not including install. It needs to be painted to initiate the warranty.
RE: Timing marks illegible - Rawze - 08-06-2020
this may help as well...
http://rawze.com/forums/showthread.php?tid=6363&pid=55386#pid55386
RE: Timing marks illegible - JimT - 08-06-2020
(08-06-2020 )eggtrucks Wrote: How do i go about doing overhead when the timing marks arent visible any more? Cm 2350
any light grit sandpaper, like 320 grit. There's 5 markings: TDC, INSERT PIN, A, B, C.
A, B, and C are spaced equally 1/3 apart around the damper.
The markings are stamped into the damper using a number of little dots and can be hard to find at first. Once you sand away the paint and rust the dots will clearly jump out at you.
The following is based on my recent experience on my engine. It may not be the same for you engine, I don't know.
When barring my engine over I noticed that about half way between each letter (A,B,C) I would meet the greatest resistance. I'm assuming it's due to the pressure building up in the cylinder. With that in mind you can bar your motor over a few times, note the locations with the most resistance then start searching about half way between them for your marks.
[attachment=6928]
RE: Timing marks illegible - Lonestar10 - 08-06-2020
Another way I've seen is start engine take a 2x4 and cantilever one end into the damper while running and the wood will polish the damper and makes marking visible then take paint marker and mark everything. Can also use engine running after this to spray paint at damper and the rotation will keep the paint from getting to thick and will leave stampings visible
RE: Timing marks illegible - tree98 - 08-06-2020
(08-06-2020 )Rawze Wrote: this may help as well...
http://rawze.com/forums/showthread.php?tid=6363&pid=55386#pid55386
This is what i did on my 870, worked great found all the marks.
RE: Timing marks illegible - JimT - 08-06-2020
(08-06-2020 )Lonestar10 Wrote: Another way I've seen is start engine take a 2x4 and cantilever one end into the damper while running and the wood will polish the damper and makes marking visible then take paint marker and mark everything. Can also use engine running after this to spray paint at damper and the rotation will keep the paint from getting to thick and will leave stampings visible
Just be careful that the 2x4 or your hands don't get kicked out toward the fan or belt. Not only would it not be pleasant, but you could end up with bigger repairs. I'm not saying it can't work or that it's a bad idea, but I've seen and experienced enough unintended consequences to make me cautious. It's all good until that split second that something unexpected happens.
RE: Timing marks illegible - 74bassman - 08-06-2020
If they are not visible good chance there is over 500k miles on it? time to replace?