5.7 Distributor TB IV rotor movement normal?

PitchFork

Petty Officer 1st Class
Joined
May 28, 2009
Messages
313
I was changing the distributor cap and rotor and noticed the rotor would move back and forth back 3/8" to 1/2" by twisting the rotor CW and then back CCW. Is this normal or signs of wear of the pin roller that contacts the Cam?

Also I need to change the gasket on the distributor because it is allowing oil to leak. To change it do I just unbolt the clamp and pull the distributor up and out and then slide it back down with the rotor facing the same direction as it came out? Any thing to look for or inspection of the distributor?

Thanks in advance
 

fossill

Chief Petty Officer
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Jun 20, 2009
Messages
427
Re: 5.7 Distributor TB IV rotor movement normal?

Normal and yes.

Do a google search of "how to" and you'll get detailed generic instructions.
 

zbnutcase

Commander
Joined
Sep 19, 2009
Messages
2,055
Re: 5.7 Distributor TB IV rotor movement normal?

NOT normal. TB distributors have no mechanical advance; they have a solid shaft and the only play you feel is between the cam gear and driven gear on dist. 3/8 to 1/2 WAY too much, sure its not a rotor issue?
 

PitchFork

Petty Officer 1st Class
Joined
May 28, 2009
Messages
313
Re: 5.7 Distributor TB IV rotor movement normal?

NOT normal. TB distributors have no mechanical advance; they have a solid shaft and the only play you feel is between the cam gear and driven gear on dist. 3/8 to 1/2 WAY too much, sure its not a rotor issue?

So when I pull the distributor out I should inspect the distributor gear for wear. I will pull the rotor off and try to rotate the solid shaft as the rotor may have been turning on the shaft and the shaft may have not been turning. I will check this when I get home from work today.

Thanks NutC
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: 5.7 Distributor TB IV rotor movement normal?

I suspect he is moving the whole shaft, and walking up the cam gear. It is typical to have some play in there, caused by gap between the top of the gear and distributer body. Not sure what would be too much. The Merc service manual may cover that, but I think it only discusses out of round. I can't access the manual to check from here. There are distributer shims to take up the play. Easy to install with the distributer out. You have to remove the roll pin in the gear. Most of the time the gear will walk up the cam gear and stay there when the motor is rotating. Might get some timing fluctuation at idle or after pulling back on throttle.
 

fossill

Chief Petty Officer
Joined
Jun 20, 2009
Messages
427
Re: 5.7 Distributor TB IV rotor movement normal?

Hmm, I may stand corrected on that one. All of he distributors I worked on all had some play in them, either mechanical advance type or the computerized variety. Let us know what becomes of it.
 

PitchFork

Petty Officer 1st Class
Joined
May 28, 2009
Messages
313
Re: 5.7 Distributor TB IV rotor movement normal?

I suspect he is moving the whole shaft, and walking up the cam gear. It is typical to have some play in there, caused by gap between the top of the gear and distributer body.

That is exactly what is happening. The 1/2" measurement was taken from the end of the rotor tip. I pulled the rotor off and the solid shaft moves every little like the cam gear is getting walked up.

Thanks all is normal just wiating for my new Dist Cap and rotor to arrive.
 
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