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Distributor Installation - How To -- 1 of 1
[font=Arial,][/font]Those who have done it before find it simple, but for a first-timer, well that's another story. At a casual glance it seems simple, but if do a Forum search you'll finds lots and lots of posts from guys who haven't been able to fire their engines after replacing the distributor. There are actually two things that must be aligned properly; the rotor tip and distributor shaft/oil pump drive. Getting those two in the proper position/index is the key. Here's what I'd do. After removing the distributor cap, I'd mark the location that the rotor tip is pointing. When you install the new distributor it's rotor tip must point at the exact same spot, so this is crucial for a quick fire up. MAKE SURE THE ENGINE IS NOT TURNED OVER/BUMPED WHILE THE DISTRIBUTOR IS OUT OR A WHOLE DIFFERENT PROCEDURE HAS TO BE USED TO INSTALL THE NEW DISTRIBUTOR. Next is the indexing of the distributor shaft with the oil pump drive rod. When you remove the old distributor, the distributor gear will turn. It has to otherwise you wouldn't be able to remove the distributor. This also turns the oil pump drive rod. Now, when you go to install the new distributor, with the rotor tip pointed at the exact spot you marked, the distributor will not drop all the way down onto the intake manifold. Why? Because the slot in the oil pump drive rod is not correctly positioned to index with the distributor. So if you move the distributor gear so that it indexes with the oil pump drive, then the rotor tip will not be pointed in the correct direction. What to do? There are basically two ways to get them both in the correct position. One is to drop in the new distributor with the rotor pointed correctly, then use the starter to bump the engine over. As you bump the engine, the distributor rotor will turn (and thus the distributor gear AND the distributor's shaft), but the oil pump’s drive rod will NOT turn since it isn't indexed with the distributor). As you bump over the engine, at some point the distributor and oil pump drive will properly index (align with each other) and the distributor will drop all the way down onto the intake manifold. Don’t forget to slide the gasket onto the distributor before doing this or you’ll have to pull the distributor to install the gasket and, then, do this all over again. Since the distributor and camshaft gears were meshed when you began the bumping, the rotor position will continue to be correct, assuming you pointed it in the exact same position as the old distributor had been in. The ignition timing will need to be tweaked once the engine is running though. The OTHER way is to use a long screwdriver. Remove the distributor, insert the screwdriver into the distributor hole all the way down until the tip of the screwdriver indexes with the oil pump drive. You’ll probably need a strong light to be able to see down in there. Turn the screwdriver (and thus the oil pump drive), then re-install the distributor and see if the oil pump drives index while AT THE SAME TIME the rotor tip is in the correct (marked)position. If not, pull the distributor, again, screwdriver, turn, re-install, check. You'll have to keep doing this until BOTH the oil pump drive and the rotor tip are correctly indexed/positioned. The way to tell in which direction the oil pump drive needs to be turned, look at the very underside of the distributor; look through the bottom of the hole in the gear. You'll see the drive tang. That is what fits in the slot of the oil pump drive. So the oil pump drive rod needs to be turned so that when the distributor is dropped in with the rotor properly positioned, the tang will drop into the oil pump slot. It may take several attempts to get them both correctly positioned using this technique. Bumping's a lot easier though. Once the distributor's in, re-install the hold-down clamp and bolt, tighten the bolt enough to still allow the distributor to be turned by hand. Make all the electrical connections and use the correct procedure for setting the initial timing for your particular engine. Once the intial timing is set, tighten the distributor clamp to the correct torque; the 86 Vette calls for 25 lb./ft.
