Changing timing chain and locating TDC

[mdregister]

Would someone please explain the process of locating TDC to me?

I need to replace my timing chain, and one book I have indicates I must locate TDC in order to do this. My shop manual, however, makes no mention of this. The shop manual indicates I should align the marks on the old gears by rotating the engine and then re-install new gears/chain with the marks in the same orientation, then time the motor dynamically.

Brittanic indicated to me the procedure for locating TDC was somewhere in the member's content, but I have been unable to locate it.

Thanks!

[catmandoo]

if the chain hasn't jumped,you can just line up the marks,when you pull the waterpump off you can look in at the gear for the injector pump,clean the edge off all the way around it and you will see a little dot ,this is the mark for the pump timing,and if you roll the crank til it is at the bottom it will meet the dot on the cam gear,also the timing mark on the crank should line up with the pointer .but if i remember correctly and i have my cover off right now but haven't started yet the crank needs to be rotated one turn to line up the cam to crank gears,i'll be doing it this afternoon and i'll let you know for sure.also while your there put on a new harmonic balancer

[mdregister]

Thanks for the reply!

I do not think my chain has jumped, just worn.

Let me make sure I understand what you said correctly.

You are saying the service manual is correct?

Just align the crank and cam dots, remove the gears/chain, and re-install new chain/gears in the same orientation, with no need to locate TDC with a dial caliper?

[catmandoo]

as long as the dots line up the keyways have to be in the correct position,and i changed mine today.heres what i did.pull all things to gain access to the timing cover,then take a chisel and scribe a mark where theinj pump meets the timing cover,then pull the waterpump,now you can see the inj pump driven gear,the cam gear is behind the gear it drives off of.now turn the crank til the timing mark lines up with the pointer,either there will be a dot on the bottom of the inj pump gear or not,if not then the motor is on top dead center,if there is a dot it's 180 degrees off.so an easy way to do it is get the pointer lined up and no dot showing then pull the timing cover,then the timing gears are lined up,just replace them,then put the inj pump gear on the cam gear but don't tighten,roll the crank one turn til the dot is on top then put the gear on the inj pump and line up the marks,make sure you tighten the cam gear bolt at this point.then tighten the pump at the previously set marks and put everything back together.