Need some advise on tdc

[Chemicalblue]

Ok heres the problem. I was hearing a slight noise in the front of the motor so I removed the front cover. I found that the timing chain had alot of play on the slack side. So in my messing around w/ the chain I lost tdc. I lined up all the marks top and bottom and now when I turn the motor its hitting the valves. Its easy to set the cam at tdc but how do i set the bottom end at tdc? In the service manual it just has diagrams to set it with the motor out and taken apart, I really dont have time to tear it all down now. Is there a way to get around this, any help or advise would really be great.

[olie05]

One way to get it at tdc is to stick a blunt pencil down the sparkplug hole and turn the motor slowly (make sure the pencil is touching the top of the piston). The pencil will rise and fall. Stop turning the motor when the pencil gets to its highest point, and that should be tdc. You can verify with the timing marks on the crankshaft pulley, but sometimes, even those are wrong.

[george.bryant]

welding rod or somthing down spark plug hole and turn crank clockwise until it comes up. taht is not true tdc and it could be 180 degrees out but the mark on the crank pulleu should telll u

[73ZCAR]

Hey, C.B.

 

You can do this without pulling the front cover but it is a P.I.T.A.

 

Please read entire post before attempting this procedure.

 

1. Make note of and mark cam gear location on cam. I use something like whiteout. Just mark the cam pin and the hole it is in, If the gear is in the stock location the #1 on the cam gear will be at about the 2:45 position, at T.D.C.. The top bright link on the chain should coincide with this #1.(there are 2 bright links on the chain)

 

2. If the cam gear and bright link are not in the position noted above then remove all rockers and lash pads at this time to facilitate movement of crank without valve damage.(make sure all valves are closed before movement of crank!!!)

(If doing this ziploc baggies are reccomended, mark cyl.#'s and int.-exh. on each bag.)

 

3. Remove harmonic damper, remove front seal carefully.

(if you do you can reuse it), remove oil slinger,noting it's orientation.

 

4. Using a flashlight, and a mirror if you have to, look for a small hole (2-3mm) on the small crank timing gear. If timed correctly it should be at about the 3:00 position at T.D.C., and the second bright link should be on it also.

 

5.If the above is not timed correctly,remove the dist cap, and with the whiteout mark the rotor and its orientation on the dist. body.

 

(AFTER REMOVING ALL ROCKERS)

((and while holding the dist./oil pump drive gear on the nose of the crank in place)THIS IS IMPORTANT)saves time later

 

6. Rotate the motor until the bright link lines up with the small hole on the crank and it is on the right side of the motor at the 3:00 position.( you may have to rotate the motor up to 6 times for this to happen) Both bright links should be on the right side of the motor with 42 links from one bright link to the other.

 

7. With the small hole and the bright link on the crank aligned, and both links on the right side W/appx. 42 links between them, wedge the chain in place with the customary tool. then remove the bolt from the cam gear. Pull the cam gear from the nose of the cam and realign the bright link and the #1 back up, resetting the cam timing. Replace bolt and retorque.

 

(for those of you with homemade wedges you must be able to insert the chain wedge and remove it with the cam gear in place)

 

8. Make sure that the dist/oil pump drive gear has not moved from its correct position up against the crank, check the marks you made on the dist. body and the rotor to make sure nothing moved.

 

If it didn't move reassemble. (don't forget the oil slinger)

 

9. If it did, then grasp the rotor and turn it to push the gear out. Rotate the dist./gear until your marks on the dist. and rotor lign up, using the rotor to pull the gear back in place and check alignment.

lign them up and then reassemble (don't forget the oil slinger)

 

(don't forget the chain wedge)

 

 

Hope this helps.

 

Mike.

[73ZCAR]

BTW, Oil pressure in the tensioner takes up the slack you had found in the chain when the engine is running.

 

Mike.

[Chemicalblue]

Tnx Mike

 

"crank and it is on the right side of the motor at the 3:00 position"

 

Thats what I was looking for. Im thinking of just removing the cam to let the valvs come up, seems like less work. The front cover is off at this time so access will be easy to fix the crank location. The slack was in the 1-1.5" range and the service manual indicated that the tentioner should be at 0mm when adjusted. So when I started I just moved the guide on the left side over a bit, seemed to fix it. Then the timing issue came up. The only thing that I seem to mess up every time is putting the oil pump/dist in the right location. I usally have to take the oil pump off a few times and mess with it a bit. good times:)