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How to replace distributor drive gear


hunter4ever12
11-02-2012, 01:34 PM
I have a 92 k1500 with the 5.0 L in it. I suspect the distributor drive gear is worn, and even if its not it isn't going to hurt anything to replace it because its the original OEM drive gear and the engine has 233k miles on it. So what I'm wandering is could someone give me a step by step process removal and re installation?

Schurkey
11-03-2012, 11:59 PM
If the driven gear on the distributor is worn, the drive gear on the camshaft will almost certainly be worn in a matching pattern.

Replace one but not the other = short-time fix.

WHY do you suspect the gear on the distributor is worn? They're melonized; and were fairly high-quality. The one on my '88 K1500 looked beautiful when the engine popped at 230,000 miles.



MINIMUM PARTS REQUIRED: Distributor gasket and new cam gear.

Put engine at TDC of #1 COMPRESSION STROKE.

LOOK at distributor, note how it is positioned relative to some fixed object. Maybe even use a paint pen or magic marker to reference the distributor housing position.

Disconnect wire connectors from module.

Remove distributor cap. Verify that rotor is pointing to #1 plug wire terminal of distributor cap.

Remove rotor.

STUDY the position of the reluctor and the pickup coil. Teeth on reluctor should be aligned with teeth on pickup coil, or very close.

Remove distributor hold-down bolt and retainer.

Lift distributor out of engine. WATCH rotor rotate as you lift distributor. When the distributor gear isn't meshing with cam gear, the rotor stops turning. NOTE THAT POSITION, and note location of distributor gasket (still on distributor, or stuck to intake manifold)

Put distributor on work bench. Temporarily re-install rotor. Note position of rotor tip, and dimple on distributor gear. They should align.

Use hammer and punch to knock out the roll-pin from the gear and distributor shaft.

Pull gear off of shaft. Typically can be removed by hand. DON'T LOSE the thrust washers above the distributor gear.

Push new gear onto shaft, aligning roll-pin hole AND dimple-and-rotor-tip.

Install roll pin.

Install distributor with new distributor gasket, with rotor in proper position. As distributor gear is meshed with cam gear, rotor will turn. Rotor must point to #1 terminal of cap when distributor is fully seated, just like before. Turn housing to same position as it was before you started. Rotor is in same position as before, housing is in same position as before. THEREFORE, THE RELUCTOR AND PICKUP COIL TEETH ALIGN EXACTLY AS BEFORE.

If required, either turn oil pump drive shaft so distributor fully seats on intake manifold OR rotate crankshaft EXACTLY two revolutions with hand-pressure on distributor to force alignment with oil pump driveshaft. Either way, distributor must seat on intake manifold AND EVERYTHING ALIGNS like when you inspected before beginning to disassemble.

Snug distributor retainer and bolt.

Install wire connectors to module.

Install rotor and distributor cap.

Start engine, use timing light as specified by service manual to properly adjust timing. Final-tighten distributor retainer bolt.

Done.


OPTIONAL BUT RECOMMENDED:

When the distributor is out of the engine, and the gear is off the shaft--TOTALLY DISASSEMBLE, INSPECT, AND CLEAN/RENEW the distributor components. Pay particular attention to scoring on the shaft, the pickup coil, etc.

If the shaft is scored...you're done. Get a different distributor. The bushings will be ruined, and you'll be better off to find another distributor than to replace the bushings and find another un-scored shaft.

j cAT
11-04-2012, 08:46 AM
I have a 92 k1500 with the 5.0 L in it. I suspect the distributor drive gear is worn, and even if its not it isn't going to hurt anything to replace it because its the original OEM drive gear and the engine has 233k miles on it. So what I'm wandering is could someone give me a step by step process removal and re installation?

only use an OEM drive gear part. this part is made to wear out over time because it is of a material that will not wear much the cam gear. aftermarket distributor gear have been reported to be too hard of a material , then the cam gear wears and you have more work to do.

on the 5.o L engine you may not need to do this . remove the distributor and check for wear on the gear.

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