Timing belt marks?

Tiny
RANDYKOS
  • MEMBER
  • 1993 PONTIAC GRAND PRIX
  • 3.4L
  • 6 CYL
  • AUTOMATIC
  • 150,000 MILES
The timing belt broke while driving. Everything thing I've read, heard, know and seen is when that happens there's more to do than just replacing the belt.

So, I bought a new Timing belt and cleaned up everything and checked by spinning the motor by hand to make sure it wasn't binding or clunking noise from a piston or lifter, and I didn't hear anything or see anything.

So, my issue is I don't know how to get the cam pulleys in sync with the crank pulley.
I know where the timing mark is on the crank pulley and motor but I don't know on the cam pulleys. There are symbols on the cam pulleys ( square w/gm in it, triangle w/1in it, squiggly arrow, a 5, a 0, and a 5) I don't know if they mean anything as far as a reference but also I didn't see anything on the motor by each pulley that could be a reference. So how do I line everything up so it's all in sync and Timed. Please Help.
Saturday, March 30th, 2024 AT 9:19 AM

5 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,476 POSTS
Timing Belt Marks in the Post Below.

Your engine has a timing chain which the marks or used by the crankshaft and camshaft keyways need to point straight up so I would make your own marks on the gears to correlate with the keyways:

The OE manufacturer does not specify if this engine is an interference engine or not.

1. Front cover.
2. Align timing marks on sprockets so that they are as close together as possible.
3. Timing chain damper.
4. Camshaft sprocket bolts.
5. Camshaft sprocket and chain.
6. Crankshaft sprocket.

Clean
Timing chain
Sprockets

Inspect
All components for wear and/or damage.

Install or Connect

Important
If the pistons have not been moved in the engine, go to Step 3, otherwise Step 1.

1. Turn crankshaft so that number one piston is at top dead center.
2. Turn camshaft so, with sprocket temporarily installed, timing mark is straight down.
3. Assemble timing chain on sprockets with timing marks in their closest together position
4. Timing chain and sprocket.
5. Camshaft sprocket bolts.

Tighten
Sprocket bolts to 100 No.M + 90° (74 lbs. Ft. + 9O°).

6. Timing chain damper.
7. Front cover.

Check out the images (below). Let us know if you need anything else.
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Saturday, March 30th, 2024 AT 12:41 PM
Tiny
RANDYKOS
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Thanks, Ken, for replying.
The motor is a 3.4l w/Twin Duel Cam. It does have a timing belt. And the car was being driven when the timing belt blew. It was shredded and broke the timing cover and made a mess.
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Saturday, March 30th, 2024 AT 5:39 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,476 POSTS
My bad, I apologize, the 3.4 has a belt, here are the instructions on timing belts marks.

Install or Connect

Notice: Do not bend, kink, or pry on camshaft timing belt as damage may occur.

1. Camshaft timing belt by routing it around sprockets and idlers.
A. Start at intermediate camshaft sprocket and work counterclockwise when looking at front of engine.
B. Make sure not to accumulate slack in belt as you work belt around sprockets.
2. Tensioner pulley.
A. Use a flat magnet, tape or cup plug to hold pivot tube in pulley.
B. Install the pulley and remove the flat magnet, tape, or cup plug.
C. Start tensioner pulley bolt. Tighten tensioner pulley bolt to 15 Nm (11 ft. Lbs.) Plus 40° using J36660, or tensioner pulley bolt to 50 Nm (37 ft. Lbs.).
3. Install tensioner bushing into side plate, if removed.

Inspect

- Bushing and appropriate holes to make sure they are clean, DO NOT LUBRICATE.

4. Loosen J38613-A to realign timing belt. Rotate rear camshaft using J38614 to set timing belt on cam sprocket. Tighten camshaft hold down tool while holding timing belt in place.
5. Timing belt tensioner.

Camshaft Timing Procedure (Belt Broken)

Tools Required
- J38616-A Camshaft timing clamps.
- J38614 Camshaft sprocket holding tool.
- J36660 Torque angle meter

1. Remove camshaft timing belt tensioner.
2. Remove tensioner pulley/arm assembly.
3. Set crankshaft timing mark TDC position on from cover.
4. Install J38613-A timing belt clamps on both banks.
5. Scribe or use a paint pen to mark both camshaft sprockets inside centers, on both banks, only if original timing marks are not present.
6. Remove J38613-A timing clamp from left front bank, and rotate cam sprockets so that the timing marks are opposite of each other. Use a straight edge to verify that the timing marks are opposite of each other.
7. Install a soft jaw clamping device to the left front camshaft sprockets.
8. New camshaft timing belt by routing it around sprockets and idlers.
A. Start at intermediate camshaft sprockets and work counterclockwise when looking at front of engine.
B. Make sure not to accumulate slack in belt as you work around sprockets.
9. Tensioner pulley.
A. Use a flat magnet, tape, or cup plug to hold pivot tube in pulley.
B. Install the pulley and remove the flat magnet, tape, or cup plug.
C. Start tensioner pulley bolt. Tighten tensioner pulley bolt to 15 Nm (11 ft. Lbs.). Tighten tensioner pulley bolt to 50 Nm (37 ft. Lbs.).
10. Install tensioner bushing into side plate, if removed.

Inspect

Bushing and appropriate holes to make sure they are clean. DO NOT LUBRICATE.
11. Timing belt tensioner.

Check out the images (below). Let us know if you need anything else.
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Sunday, March 31st, 2024 AT 6:40 PM
Tiny
RANDYKOS
  • MEMBER
  • 4 POSTS
  • 1993 PONTIAC GRAND PRIX
  • 3.4L
  • 6 CYL
  • 150,000 MILES
I have a 1993 Pontiac grand prix with a 3.4l twin dual cam and the timing belt snapped when driving and the m having trouble figuring out where to start for the cam gears for timing the old marks are no longer on the gears I'm asking how to figure out how to time the gears.
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Monday, April 8th, 2024 AT 11:31 AM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,476 POSTS
Please reference the post above.
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Monday, April 8th, 2024 AT 11:32 AM

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