Pretty tough chains from factory but I replaced mine at 340k because the bottom was simplex. Took top cover off and measured tensioners and chain conditions. I upgraded to duplex setup. Pretty easy job to do yourself if you want to save $. I done a rough write up on whats involved.
Just use a test light to find youre IGN. Blacks most likely ground, one will be a memory wire and will have constant power turn IGN off to test. the rest will be speaker wires i use a AA battery and put one end of a wire on the + of the battery and one wire on the - of the battery. eventually...
https://www.navaraforum.com/threads/how-to-do-a-d22-timing-chain.39982/#post-408637
i done a quick write up. i probaly forgot a couple of things but theres the basics on a d22. hope it helps!
CHEERS!
If theres anything i forgot please add to this, any questions ill be happy to help. ive proberly forgotten a few steps but thats the basics.
Id recommend using YD25.com.au duplex kits or mr cylinder head if youre on a budget. i didnt replace my cam cogs as there made strong from...
*I AM NOT A MECHANIC ANY ADVICE FROM THIS IS YOUR OWN RISK IM JUST A BLOKE WITH TOOLS AND A LOVE FOR CARS*
D22 YD25 2009 NIRVARA 2WD TIMING CHAIN UPGRADE TO DUPLEX.
1) Ensure your car is jacked up and front wheels are off the ground and rear wheels choked
2) Remove batterys
3) Drain...
Harmonic balancer is tighten to 75NM then undo 360 degrees then tighten back up to 75NM plus 120 Degrees. Have fun! i just done my timing chain upgraded to duplex on a d22, prick of a job much easier in your d40.
I used Toyota black and red that I had left over from my landcruiser rebuild.
Any RTV for engine oil would be fine. Make sure you let it set for 24hrs before adding oil etc.