I wondered about that too when I reconditioned my head.
You'll see when the sump is off that the timing cover has a guide cast in it that prevents the chain from dropping off the bottom sprocket.
finally put the head back on and lined up the timing chain 2 dark links with the tdc marker in the camshaft. turned engine over by hand and when it came back to tdc, the dark chains arent lined up anymore. my question is when the head is off and the timing chain and cam gear are sitting in the guides. can the chain slip on the bottom gear a link or 2 ? thus what i though was tdc on the bottom gear was actually out when i took up all the slack turning it over by hand.
i am about to pull the sump to check the oil pump bolt while it is all in a state of not going anyhow. will check it all then. but i am hoping it is as simple as this.
I wondered about that too when I reconditioned my head.
You'll see when the sump is off that the timing cover has a guide cast in it that prevents the chain from dropping off the bottom sprocket.
-- Paul --
| '99 Discovery Td5 5spd man with a td5inside remap | doesn't know what it is in for ...
| '94 Discovery Tdi 5spd man | going ... GONE
HI Rosscoe
Sorry can't help with the TD5 but my experience with other petrol timing pelts and chains is that it can take a few turns of the engine for the marks to line up with the chain and timing marks. I havn't done a TD5 but are there marks on the cam wheel the you can line up and the check the bottom mark on the crank shaft to make sure it is all lined up, ignoring the marks on the chain as they have now been rotated off the exact mark.
Just a thought. and I stand to be corrected on this.
I remember on the Datsun 1600 we used to make a wooden block to jam the in place to hold the chain on the crank end of the show.
How long did it take you to put take the head off and on again?
I may have missed it else where but why did you take it off in the fist place?
-- Paul --
| '99 Discovery Td5 5spd man with a td5inside remap | doesn't know what it is in for ...
| '94 Discovery Tdi 5spd man | going ... GONE
yeah, turned it over a few times by hand as i thought the same thing, might take a few to line up, but no it keeps not lining up the same amount of links out each turn. i too thought there was a guide down below to prevent this from happening, i just can't see how it can be out.
checked the crank was lined up before i timed the head when it was put back on. head had a dowel in the cam to stop it in the correct spot. the chain had the 2 dark links lined up with the line in the gear and the tdc dowel in the cam. all good
turned it over by hand and its out
all not good
If you keep turning it will eventually line up. It takes heaps of revolutions. If you can fit the crank and cam timing pins at the same time, it will be timed correctly.
Remeber camshaft sprocket is different size to crankshaft sprocket. Crankshaft has to turn 720 degrees for camshaft 360 degrees. 2 to 1
Contrary to other posts the chain can move on the crankshaft sprocket.
The dark links are your maintenance guide not mandatory for engine function.
IF you have correctly locked and aligned the crankshaft and camshaft the timing will be right regardless of the chain links. Though having the guide links in the correct place may make it easier for future mechanics if not you.
cheers
I agree with the above.
The crank locking pin goes in the bottom of the bell housing.
I use an air fitting drilled out to the right size.
Screw in and fitt the drill bit shank first.
I rotate the motor till the crank pin "falls" in and then check the one on the cam.
A lot of adjustment so worth the time to get right.
After tightening all 3 bolts undo 1 at a time to loctite.
so am i correct in assuming there is only 1 spot in the inspection hole for the crank locking pin to go into, so if the locking pin goes in and the can locking pin is lined up, even if the dark links aren't lined up i am ok ???
if so, i can move the chain when i drop the sump in the next step to check the oil pump bolt. but would like to get the car going first though so i can put it on the concrete to jack it up and drop the sump.
If the crank and cam pins go in when the motor is turn in direction of rotation all is good.
The single and double link are for the base set up to get things close(pre counted links).
I think there is only one slot for the crank pin but maybe check with JC or BN to confirm.
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