aaklingler
Registered User
How do you find top dead center on the harmonic balancer? What do you line up?
top dead center???
- Thread starter aaklingler
- Start date
79jasper
Chickenhawk
There'll be a grove cut in it.
Timing tab should be numbered.
Clean it, scrub with a soap stone, then lightly wipe off the excess.
Timing tab should be numbered.
Clean it, scrub with a soap stone, then lightly wipe off the excess.
icanfixall
Official GMM hand model
Look at the timing tab spot weled to the front gear cover. The bottom large diameter short probe location is the number one top dead center mark. Riotwarrior had a great pic of this somewhere. May have been someone else too. But thats the spot your looikng for. Clean off the dirt and you will find the stamped line and the "0" mark on the line. Want to know how to determine when the number one piston is at top dead center.. Remove the #1 glow plug and hand crank the engine slowly and place your finger over the hole where the plug was. DO NOT PLACE YUOR THUMB THERE AND LET ANYONE CRANK THE ENGINE WITH THE STARTER.. Thats a good way to loose a thumb or finger. You have about 500 lbs of air escaping from that hole when its cranking fast. Don't believe it.. Well come back here after you return from the ER where they try to save your finger or thumb.....
When the line/groove is at the 11:00 O'clock position then #1 & 4 pistons are at TDC. Like Gary said, the line/groove should be at the zero mark. If you would need an exact TDC, then you would have to pull the pass side head. There is no way to see or measure like you can a gasser thru the spark plug hole.
aaklingler
Registered User
Thanks guys, the dowel pin on the ip should be at 12 o'clock, correct?
icanfixall
Official GMM hand model
You must be registered for see images attach
Actually I think the drive dowel pin should be at the 4 o clock position. The three drive bolts should be set so tha bottom one in directly straight down in relationship to the "Y" timing mark on the injection pump gear.
Not sure what yer after, hope this helps
Some where there is a way to get it damn close using these marks...I'd think at least.
Let us know what and why.
JM2CW
Al
You must be registered for see images attach
You must be registered for see images attach
Some where there is a way to get it damn close using these marks...I'd think at least.
Let us know what and why.
JM2CW
Al
icanfixall
Official GMM hand model
I suppose you could remove the passenger side valve cover and watch for the intake valve rocker to close. Then continue to hand crank the engine up till the timing marks look like the pics above.. Thanks Al for the great pics once again.. Nothing makes my day more than good clear pics. Nobody likes to look at blurred out pics. We want to see something.. Not guess..
Dsl_Dog_Treat
I lost my face to the jaws of a poodle
That's how I dial em up to TDC.
icanfixall
Official GMM hand model
When your looking at this above timing marks caution must be taken. When the timing looks like this your either at number one tdc or number four tdc. Both pistonsa are up top at the same time. Only the valve action differanciates which cylinder is going to fire. Number four cylinder could be about ready to open the intake valve. Then its open till the piston reaches the bottom of the stroke. Then it closes and when it up top of the stroke it wil fire. But in the same 360 degrees of crank rotation the number one cylinder has fired. Is on its way down to bottom dead center using all the combustion power. Then the exhaust valve opens and the piston returns to top dead center and all the hot exhaust gas is pushed out. Then it starts all over again.. Sucks. Pops. Blows and goes...
THE OP has not responded and the issue we need to address is WHY this information is required before spoon feeding theory to the OP
I'm wondering if there is an issue of gear cover off IP replacement???? If so this could be the reason needed for the info. That being said if it is; then there are two potential issues but light on the gears while aligning the 0 degree timing mark.
Clearly Gary's stacked timing gears and my pic come into play here. If my mark is on Gary's marks can be on or 180 out.
Thus lets find out what and why the OP needs the info and proceed to help from there.
JM2CW
I'm wondering if there is an issue of gear cover off IP replacement???? If so this could be the reason needed for the info. That being said if it is; then there are two potential issues but light on the gears while aligning the 0 degree timing mark.
Clearly Gary's stacked timing gears and my pic come into play here. If my mark is on Gary's marks can be on or 180 out.
Thus lets find out what and why the OP needs the info and proceed to help from there.
JM2CW
Correction, you are at BOTH 1 and 4 TDC at the same time, ts just that one of them is at Compression stroke TDC and the other is at axhaust TDC and on the next rotation its the other way around.. THis is why you can time off either one and be corrrect.
aaklingler
Registered User
Thanks guys, my buddy pulled his ip gear housing off to change IPs and he got his teeth off putting it back together.
icanfixall
Official GMM hand model
Well there we go.. Sadly the friend didn't come her before turning a wrench.. Now figureing out where the issue of the gears and top dead center number one. Then remove the pump and then the cover. Lift out the gear. Draw a line from the "Y" mark all the way up to the top of the gear. Set the gear back in the cover to mate up with the cam gear. Watch to see that the "Y" timing marks line up on the injection pump gear and the cam gear by the line being straight up and down with an right angle square. That line will be in the middle of a small cutout in the front cover plate..
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