Correct Timing?

timothyd · **Joined:** Wed Feb 20, 2019 2:58 am **Posts:** 90

Im probably overly nervous but I did the TB on the CRD the other day, it fired up fine and seems to run fine. I bought it and parked it until I could to the TB so i'm not used to the sounds it should make but, my question is, would it even start if the timing was off at all? I only ask this because after putting it all back on and going to hand rotate it, pulling the pins out required me to move the crank just slightly to back the pins out. Could this much play affect timing at all? Would it even run if it was slightly out of timing?

flash7210 · **Posted:** Sun Apr 07, 2019 7:57 pm

I think you’re all good.
You can be +\- 2 crankshaft degrees and not have any problems.

TKB4 · **Posted:** Mon Apr 08, 2019 7:48 am

I think you are good too. But if you are worried just try to put the pins back in to check it now. The only thing that ever worries me is if the TB tensioner wasn't tight enough to maintain tension or slipped. I always keep turning it by hand and resetting the tensioner until there is no change a few complete cycles to get all the stretch etc out.

Remember there is an exact number of teeth on the timing belt I think either 72 or 77 or so and an exact number of teeth between cam gears and fuel pump and crank and water pump. The timing really cannot be off at all unless its off at least a whole tooth which would be about 5 degrees. I don't believe you could pin all three places at all with it off this much or get the TB back on tensioner at all. really about the only thing that could change much at all is if you remove the cam gears and got them back on just a fraction off but still able to get tooth in groove on gear. So if you had all three pins in with Belt on and tensioned you have it correct.

I am sure that even if you used an allen wrench etc in crank rather than screwed in crank pin which I never use even though I have it the correct flywheel hole would have to be the one used the other holes are not that close.The crank can be moved a little even with at least two of the three pins in and probably even less with all three but it can be moved some pinned in correct timing.

So put pins back in to check its you want but you have it correct.

jaffazoom · **Joined:** Mon Aug 06, 2018 4:13 am **Posts:** 5

Quote:

The timing really cannot be off at all unless its off at least a whole tooth which would be about 5 degrees.

Agreed unless you had the cam gears off the cams as there is no key way to locate them and so even if the gears are all lined up the cams can be anywhere.
Absolute pig of a design.

TKB4 · **Posted:** Fri Apr 12, 2019 7:08 pm

Even if you loosened the cam gears as long as you torque them to specs when replacing it still cannot be off more than whatever play the pins allow when installed. The cams are held in the correct position for 90 degrees ATDC while the cams gears are loose by the cam pins. If you line up fuel pump timing mark also u cannot be off and get timing belt on the cam gears. Thats why I torque the cam gears after putting Timing Belt back on.

DieselJeepLuvr · **Posted:** Mon Apr 29, 2019 2:12 am

The timing belt tensioner is adjusted with the cam gear bolts loose. The cam gear bolts aren't torqued until the injection pump is timed and the belt tensioner tightened. Once the belt is tight and the IP timing marks are in perfect alignment THEN you torque the cam gear bolts (using the cam gear locking tool) After that is done you can remove the guide pins in the cams and Flexplate (and they should come out easily unless one got bent or something).

WWDiesel · **Posted:** Mon Apr 29, 2019 12:06 pm

DieselJeepLuvr wrote:

The timing belt tensioner is adjusted with the cam gear bolts loose. The cam gear bolts aren't torqued until the injection pump is timed and the belt tensioner tightened. Once the belt is tight and the IP timing marks are in perfect alignment THEN you torque the cam gear bolts (using the cam gear locking tool) After that is done you can remove the guide pins in the cams and Flexplate (and they should come out easily unless one got bent or something).

And it is also recommended and a good practice after removing the timing pins, torquing the cam bolts and belt tensioner, to manually rotate the engine four full revolutions by hand using the big nut on the end of the crankshaft.
Once you do this, reindex the crankshaft back to the 3:00 timing position, reinstall the flexplate pin and then see if both cam pins can be reinstalled easily. If the cam pins won't go in, it was not timed properly.
(please note: crank rotation must be even numbers, i.e. 2, 4, 6, etc... as the cam timing alignment holes will only line up every other rotation of the crankshaft at the 3:00 timing position.)

Correct Timing?

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