CRD timing chain & gear removal

[pollenface]

I'm about to remove my timing chain and lower gear as I need to access the bolts behind the lower gear, I am wondering how to tell when cylinder 1 is at TDC?

Also the Nissan learning resource advises not to use an impact wrench on timing gears, but I've watched a video where a professional looking fellow guy just rattles the top gear nut off, I'm guessing this applies to tightening and not loosening?

My next question is, what is a good way to lock the motor during loosening/tightening? Can I just jam some rag in the gears?

[mihit]

There should be timing marks on literally everything.
TDC on #1 sgould be indicated on crank pulley and timing cover. Also the cam-lobes vs valves for the cylinder will both be slack


Not sure what you mean timing gears? The one(s) attached to cam shaft(s)? They also should have marks, one between teeth and one on a tooth. They will only mesh and line up with keyway correctly, or backwards.
If you mean the one on the crank, it should be a one-way jobby, maybe tapered, definitely keyed.

I would smash the crank bolt off, then hand tighten it again, line up TDC and go from there. Again, as long as your marks all line up, you can't go too far wrong (maybe )

[pollenface]

Thanks, I'll see what happens.

[pollenface]

I've turned the motor over about 10 times and nothing is lining up.

The yellow link on the chain does not line up with the mark on the fuel pump sprocket. The two grey links do not line up the marks on the cam sprocket.

The C on the fuel pump gear doesn't line up with the CC on the crank. The AA and BB on the idler gear between the cams will NOT line up with the A & B of the cams. No amount of turning the motor over can correct this.

I can get the A, B and CC in what I believe is the right position but the AA,BB & C are out.

Has anyone seen this before? I believe the cam idler and fuel pump gear where not installed in the correct orientation from the factory.

20230906_111403.jpg20230906_111318.jpg

[mihit]

Now there's a conundrum. I don't think the motor would have run if it was at-all out, or installed wrong.

Cam-degrees are 50% of crank degrees, (how many cylinders is the thing?) so it may take more revs than 10.

Are you at TDC on #1 when any of the marks line up?

Not sure what the coloured links on the chain are about...that's a new one on me.

[pollenface]

Crd 3.0 is 4cyl.

All other info remains the same as my above post.

C on the pump gear does not line up with CC on the crank.
A & B do not line up with AA and BB on the cam idler with any amount of turning of the motor.

For the coloured links, you just have to look at a picture of a crd timing chain.

[pollenface]

I pulled the fuel pump drive gear off today. Interestingly even though there's a keyway in the the lower timing chain sprocket, there's no keyway on the shaft or key bit. It's just held in place by a tight nut.