Motorcraft Spark Plug ??

[93MTXSHO]

Which way do the washers go on the Motorcraft Spark plugs? Are they even necessary? One side is slightly larger than the other and has a slight convex curve. The other side is smaller and concavely curved. Thanks in advance.

 

[BlackOnBlackATX]

this may have been dumb on my part but i couldnt figure out what to do with the washers either so i left them out. havent had a problem yet. hope it helps.

 

[gosho89]

Yes use the washers, and put a little anti-seeze on the threads of spark plugs anytime you installed them in aluminum heads. I don't think its real important which way the washer goes, its just design to crush together one ring inside the other to create the seal. I put the the large end of washer next to the plug and the smaller side to the cyl head. Thats always worked for me. Make sure not to over torque, 17-19 foot lbs is all thats necessary thats enough to completely crush the washer.

<small>[ December 07, 2002, 09:36 PM: Message edited by: gosho89 ]</small>

 

[luigisho]

For some reason I think the larger end of the washer goes toward the head.

 

[projectSHO89]

I had this same question when I last installed plugs. Could not find an answer in the '89 service manual.

As said, probably doesn't matter which way they go, as long as they are there.

Steve

 

[Mr Anonymous]

From Scott P's valve gapping procedure document: Install the washers on the plug threads with the wide side of the ****** facing the head and the narrow side facing the plug seat.

 

[pjtoledo]

SHOooo:
From Scott P's valve gapping procedure document: Install the washers on the plug threads with the wide side of the ****** facing the head and the narrow side facing the plug seat.

That makes sense, wide part of the washer on the soft aluminum, narrow part on the steel plug.

Perry Toledo,Ohio

 

[shojuan]

SHOooo:
From Scott P's valve gapping procedure document: Install the washers on the plug threads with the wide side of the ****** facing the head and the narrow side facing the plug seat.

Hehe, I read that too when I did my 60K. Funny thing was that my original, factory installed spark plugs had the crush washers installed just the opposite: wide side facing plug seat, narrow side facing head. I just did mine the way it came from the factory.
Probably doesn't matter much either way.

Rick

 

[gosho89]

Hey Rick,

Now you mention it I remember seeing the same thing. But again its just a crush seal against two flat surfaces either way should be fine.