Ford distributor stator replacement

[olddog]

Ok this is my Cobra which has a Mallory 7970404 distributor, however Mallory states and I quote "Factory distributor ignition modules and stators interchange with the Performance Replacement Distributor ignition modules and stators." Mallory does not list a replacement part number for the stator.

Bottom line think of this as a 1990 Ford Mustang GT with 5.0 engine.

I am about to replace the pickup coil/switch or stator or what ever it is called. It is located in the bottom of the distributor. I lack the technical terms for the items. I know it is a hall affect switch, and I hear many terms intermixed by different sources.

There is a part that the TFI module plugs into. It looks like a coil. Wires go to another part that has a magnet looking piece. The magnet looking piece has a sensor on a post next to it with a wheel that runs between the magnet and the sensor. These two parts together are a unit, as the wires connecting them are permanently installed. I thought this was called the pickup switch, but the more I read the more confused I get.

The wheel has 8 notches, one for each cylinder. #1 cylinder has a different sized gap in the notch. The wheel is attached to the distributor shaft and is the only moving part. I always thought this was called the stator, but I'm not sure anymore.

I have pulled the distributor. I drove the pins out of the gear and lock collar above the gear. Slid them off the shaft. Then Pulled the shaft out of the distributor housing. The wheel is still attached.

The pickup switch (what ever it is) has a brass bushing in it and is pressed into the top of the distributor housing. It appears to have two places made in it to connect a small puller or slide hammer. It looks like the fingers of the tool to extract it can only be about 1/8" wide.

Finally my question: what is the proper tool to remove this darn thing and where can you get, rent, or borrow one?

Any clarification on the terms for these parts would be helpful.

Thanks

[thcardoc]

That sensor is a hall effect switch. A hall effect transistor turns on when in the presence of a magnetic field. The vanes on the distributor shaft block the magnetic field from passing through the hall effect transistor, while the windows allow it to pass through. Ford calls it the PIP sensor, (Profile Ignition Pickup).

It's been years since I replaced a PIP sensor, after the initial design where the plastic body simply turned to slime from the crankcase gasses they have been virtually trouble free. If you can take a photo or two it would help my memory, but it seems they are not difficult to replace. Look carefully to be sure there isn't a tiny snap ring wire holding it to the assembly.

[thcardoc]

I had some time to look up the routine for a genuine Ford. There are two small screws that hold the original assembly in place.

[olddog]

Thanks thcardoc. I have been so busy with the power off and other things, I just haven't had the time to work on this.

Well maybe the pick-up-switch is not identical to the Mallory. Mallory's web site does not list a part number for it. The statement I pasted in the first post is the only reference I found. Perhaps they meant the wheel with the window, when they said stator.

I think I'll just take it to an auto parts store and have them show me the pick-up-switch for a Ford distributor. Then I should know if they interchange.

[olddog]

http://shop.advanceautoparts.com/wcs...z_pri_larg.jpg

This is a picture of a Ford pick up switch. It looks like it may be the same. However when it is in the distributor there is a bushing inside the center hole. The bushing has a flange on top. As you can see it looks like it has two slots made for you to get a puller under the flange.

[thcardoc]

Originally Posted by olddog

http://shop.advanceautoparts.com/wcs...z_pri_larg.jpg

This is a picture of a Ford pick up switch. It looks like it may be the same. However when it is in the distributor there is a bushing inside the center hole. The bushing has a flange on top. As you can see it looks like it has two slots made for you to get a puller under the flange.

The bushing inside the cener hole could be simply the one that supports the top of the distributor shaft. There is a part called the "octane rod" that positions the pick-up. Once it is removed that center pick-up should simply slide off of the distributor body. The two screws hold the white outer portion of the sensor in the distributor body.

[olddog]

Yes. The bushing is the top bushing in the distributor. The top of the bushing has a flange on it (the outside diameter at the top is bigger). The flange is a thrust plate that the shaft sits on.

Problem: The flange is bigger than the hole in the pick-up. Therefore the bushing has to be pulled out in order to remove the pick-up. The bushing goes into the distributor about 1 inch. I have no idea what force is required to pull the bushing. The flange is about 1/8" thick, so it will not take too much force. The two slots in the pick-up appear to be designed there to allow you to get a small puller under the flange.

I had thought a small slide hammer, but that may damage the flange. I didn't know if there was a special tool for pulling it, or if anything you can rig up will work. There is always the possibility that there is no way to pull it without damaging it. I hope not.

[olddog]

Update: I tapped the two slots. Drilled holes in a plate for the spacing. Put two #8 screws through the plate and screwed into the plastic threads tapped into the switch. Then used a puller to pull the bushing. Well actually a good friend did it for me.

Turns out the bushing only goes in about a 1/4" into the housing. I miss took a step in the housing for the end of the bushing.

I replaced the switch with NAPAs best 3 yr warranty part.

Weather permitting, I will drive it to work and every hot day I get a chance. I sure hope this solves what I believe to be an ignition break down problem that only occurs after heat soak on a hot day.

OBTW - I did searches for people changing this switch in Factory distributors. No one talked about pulling the bushing, so maybe the OEM was different than the Mallory unit.