What's the easiest way to find TDC....

[Salmon Stalker]

You guys allready directed me to the coolant leak that I had recently. I replaced the intake gasket and the water pump. Yes they were both leaking. Here is my current dilema. I have tripped a SES light and had it checked today and it turns out I re-installed my distributor just a little bit off.

 

What I need to find out is what is the easiest way to find Top Dead Center on Cylinder #1 so that I can correctly install the darn thing?

 

Any help would be appreciated...

 

SS

[asepgrad98]

there should be a mark on the crank pully

[budhayes3]

I usually remove the #1 spark plug and put my finger over the hole, then I rotate the engine around to the mark on the crank pulley...when you feel compression as the timing mark comes around, it's at TDC when it's at the mark. If you don't feel compression, you have to rotate it another time.

[GM-Tech]

You didn't say what year/model, but the newer ones actually have two marks on the balancer and two "pointers" of sorts on the cover. There's one where the old timing plate used to be. It has a little indentation where the mark on the balancer should point. Then there's an actual pointer cast into the cover on the bottom, drivers side of the timing cover. The two marks should line up with those two pointers when #1 is at TDC.

[Salmon Stalker]

Ooops.... 1996 GMC Sierra 5.7 liter engine....

 

There's a mark on the crank pully but I haven't seen a pointer or any indicator that I can line it up with.

 

 

GM-Tech.... It sounds like you are saying that there should be a 2 marks on the pully and on the timing cover that I can line this up with? Is that the case with my 1996?

 

Thanks Guys.....

[mcreyaufmiller]

Ooops.... 1996 GMC Sierra 5.7 liter engine....

 

There's a mark on the  crank pully but I haven't seen a pointer or any indicator that I can line it up with.

 

 

GM-Tech.... It sounds like you are saying that there should be a 2 marks on the pully and on the timing cover that I can line this up with?  Is that the case with my 1996? 

 

Thanks Guys.....

 

<{POST_SNAPBACK}>

 

 

I had a similar problem, I just took it into the dealer and for $35 they reset the dist. These trucks have to be reset with a computer to zero out the timing. Not sure what the technical term is, but it is easy to explain this way.

[GM-Tech]

GM-Tech.... It sounds like you are saying that there should be a 2 marks on the pully and on the timing cover that I can line this up with?  Is that the case with my 1996? 

 

I was talking about the Gen III motor, but since you didn't say what year... On yours, you don't have what I described.

 

I'll go to SI and get you the whole procedure. It's a bit confusing but it's really pretty easy.

[GM-Tech]

You probably want "procedure B". I've put the beginning of that in bold down below...

 

 

 

 

Distributor

Removal Procedure

 

Notice: If the distributor is removed from the engine, it can be re-installed using Procedure A as long as the crankshaft has not rotated from the original position. If the intake manifold, the cylinder head, the crankshaft, the camshaft, the timing gear, or the complete engine was removed or replaced, Procedure B must be followed in order to correctly install the distributor. A DTC code may also indicate an incorrectly installed distributor and engine or distributor damage may occur. Procedure B must then be used.

 

Turn OFF the ignition switch.

Remove the spark plug and the ignition coil wires from the distributor cap.

Remove the three-wire hall effect switch connector from the base of the distributor.

 

 

 

Remove the two screws holding the distributor cap to the housing.

 

 

 

Remove the distributor cap.

Use a grease pencil in order to note the position of the rotor in relation to the distributor housing. Identify the mark with the number 1.

Mark the distributor housing and the intake manifold with a grease pencil for proper alignment when reinstalling.

Remove the mounting clamp hold down bolt.

Remove the distributor.

 

 

 

As the distributor is being removed from the engine, you will notice the rotor move in a counter-clockwise direction about 42 degrees. This will appear as slightly more than one clock position. Noting the position of the rotor segment by placing a second mark on the base of the distributor will aid in achieving proper rotor alignment during the distributor installation. Identify the second mark on the distributor housing at number 2.

Installation Procedure A

Remove the new distributor cap.

 

 

 

If installing a new distributor assembly, place two marks on the new distributor housing in the same location as the two marks on the original housing.

When installing the distributor, align the rotor with mark made at location 2.

 

 

 

Guide the distributor into place, making sure the mounting hole in the distributor hold down base is aligned over the mounting hole in the intake manifold.

As the distributor is being installed, you will notice the rotor will move in a clockwise direction about 42 degrees.

Once the distributor is completely seated, the rotor segment should be aligned with mark on the base in location number 1. If the rotor segment is not aligned with the number 1 mark, the gear teeth of the distributor and the camshaft have meshed one or more teeth out of time. In order to correct this condition, remove the distributor and reinstall it.

 

 

 

Install the cap and the mounting screws. Do not overtighten as they may strip. Tighten

Tighten the distributor cap screws to 5 N·m (45 lb in).

 

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

Install the distributor mounting clamp and bolt. Tighten

Tighten the distributor clamp bolt to 27 N·m (20 lb ft).

 

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

Install the three wire hall effect switch connector to the base of the distributor.

Install the spark plug and the ignition coil wires to the distributor cap.

 

Important

If a check engine light is illuminated after installing the distributor and a DTC P1345 is found, the distributor has been installed incorrectly. Refer to procedure B for proper distributor installation.

 

 

Installation Procedure B

Rotate the number 1 cylinder up to Top Dead Center (TDC) of the compression stroke.

 

 

 

Remove the distributor cap screws and the distributor cap to expose the rotor.

 

 

 

Align the pre-drilled indent hole in the distributor driven gear with the white alignment line on the lower portion of the shaft housing.

 

 

 

The rotor should point to the cap hold down mount nearest the flat side of the housing.

 

 

 

Using a long screw driver, align the oil pump drive shaft to the drive tab of the distributor.

Guide the distributor into place, ensuring that the spark plug towers are perpendicular to the centerline of the engine.

Once the distributor is fully seated, the rotor segment should be aligned with the pointer cast into the distributor base. This pointer will have 6 cast into it, indicating that the distributor is to be used on a 6 cylinder engine. If the rotor segment does not come within a few degrees of the pointer, the gear mesh between the distributor and the camshaft may be off a tooth or more. If this is the case, repeat the procedure again in order to achieve proper alignment.

 

 

 

Install the distributor cap and the mounting screws. Do not overtighten as they may strip. Tighten

Tighten the distributor cap screws to 5 N·m (45 lb in).

 

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

Install the distributor mounting clamp and tighten to the proper torque. Tighten

Tighten the distributor clamp and the bolt to 27 N·m (20 lb ft).

 

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

Install the three wire hall effect switch connectors to the base of the distributor.

Install the spark plug and the ignition coil wires to the distributor cap.

 

Important

If a check engine light is illuminated after installing the distributor and a DTC P1345 is found, the distributor has been installed incorrectly.