Distributor 4.3l 1999 Silverado

micchev99 · March 23, 2009

Thought i had did things correctly. During the tear-down to replace lower intake manifold gaskets, i marked the rotor relative to the distributor housing. But now, on reassembly, when the rotor is aligned, the distributor doesn't insert all the way. It remain about 1/8" up. I can get it to seat properly if the rotor is off by about 30 deg clockwise. I'm baffled. The bottom end of the distributor shaft has bar in it, so it looks like it can be mounted only correctly, or 180 deg off.

silveradobobby · March 23, 2009

Your hitting the oil pump shaft thats what the bar sits in, i trick you can do is sit the dist were you want it and have someone bump the engine till it seat all the way.

micchev99 · March 23, 2009

thanks ... does the distributor shaft drive the oil pump?

txab · March 23, 2009

thanks ... does the distributor shaft drive the oil pump?

Yes it does

micchev99 · March 23, 2009

thanks for the help ... is there a way to know which rotated inadvertently? the oil pump or the engine? i'm sure that is it, but I can't imagine how either turned ... the truck has been in gear w/emergency brake since beginning. can the oil pump be rotated back using a long screw driver?

Zembonez · March 23, 2009

The oil pump may have rotated when you pulled the distributor. Isn't the key in the bottom of that shaft off center? I thought it only went in one way.

bigredmariner · March 23, 2009

thanks for the help ... is there a way to know which rotated inadvertently? the oil pump or the engine? i'm sure that is it, but I can't imagine how either turned ... the truck has been in gear w/emergency brake since beginning. can the oil pump be rotated back using a long screw driver?

Yes, you can rotate the oil pump with a long screwdriver.

micchev99 · March 23, 2009

The oil pump may have rotated when you pulled the distributor.

maybe, i'm just not that familar with the details down there. you might be right, maybe when i first removed the dist i yanked it upward too quickly and the slanted spines began spinning the oil pump, and after disengagment the oil pump kept spinning due to momentum

Isn't the key in the bottom of that shaft off center? I thought it only went in one way.

not following you here ... by key, are you refering to the "bar" that i was refering too? sorry, not sure what you are saying.

micchev99 · March 23, 2009

Yes, you can rotate the oil pump with a long screwdriver.

thanks ... i found this, but it is for S10s

http://www.netquickposse.org/keeper/distrib.pdf

anyway to get the right pdf for my engine?

silveradobobby · March 23, 2009

Yes you can use a long screw driver but just bumping the engine or turing the engine by had work alot faster and easier. Yes the oil pump will turn when you pull the dist due to the gears being sprialed and when reinstalling the oil pump slot on the shaft will be off. Yes the dist runs the oil pump.

Zembonez · March 23, 2009

not following you here ... by key, are you refering to the "bar" that i was refering too? sorry, not sure what you are saying.

Well... that didn't come out quite right. For some reason I had a brain fart there and didn't finish making the point. The slot that the distributor slips into is the oil pump drive. The distributor is driven by the gear off of the cam. You can easily reposition the oil pump shaft with a slotted screwdriver.

Sorry about that.