changing spark plugs

[SteveO_71]

On my newly purchased 71, I managed to remove a sparkplug to take a look at it and it appears that the plugs could be replaced. Does anyone have any tips/tricks for changing that works for them? From the top seems tight as well as bending over the fender. Can they be changed from underneath? Plan on using Autolite 25. Is there something better? Thanks

[JTS71 Mach1]

A flex head ratchet usually works very well, as it allows you to move the handle away from obstacles but still allows you to turn the socket, Use a good plug socket with the rubber inside to slip over the plug and keeps the ratchet straight, this helps keep you from snapping the insulator. Also don't use an extension if at all possible for the same reason. All in all not to hard on an old Mustang. There's definitely more room then in most newer cars. In that old engine You definitely want the Autolite/Motorcraft Coppercore plugs. Champions are for Dodge's and Chevy's , Don't put anything but Autolies/ Motorcraft plugs in a FORD! I wouldn't put platinum plugs in anything! As I've had more failed platinum plugs over the years, then any type or brand put together! Case in point my sons 99 Explorer all of a sudden developed a dead miss, plugs were approximately 6 months old and were running fine. So checked the coil ok checked the wire ok, pulled the plug, looks fine clean no oil or other deposits????? Put new plug in it cleared the miss instantly. Another damn junk "Platinum" plug . Just my thoughts and opinions. Hope it helps. JTS 71 Mach1

[1969_Mach1]

I haven't changed plugs on a 71 Mustang. JTS71 has great information. Maybe not on your 71 Mustang, but sometime, depending on the spark plug location, using a swivel type spark plug socket and extensions helps you get to the spark plug. Plus it reduces the chance of cracking a spark plug and you don't have to be perfectly in-line with the spark plug.

For future replacement it is helpful to put a small amount of anti-seize compound on the threads of the spark plug. Then tighten them normally as you would using your ratchet setup. Don't tighten the spark plugs with a torque wrench to factory specs when using anti-seize compound. Or any fastener to factory specs with anti-seize compound on the threads for that matter. It reduces the friction so much the factory torque value is usually too high.

I also like Motorcraft spark plugs. But I prefer NGK in my Fords. I use the NGK equivalent of the correct Motorcraft spark plug. Everybody I know that has tried NGK doesn't go back. My preference for spark plugs in my cars, (1) NGK, then (2) Motorcraft, and as a last resort, (3) Autolite.

Lastly, a small dab of dielectric grease inside the spark plug boot helps to install and remove them easier onto the spark plug.

Best of luck and have fun. It's not a difficult task.

Best Regards,
Mike

[SteveO_71]

Thanks for the tips guys! I did notice one thing though. My 6 point 5/8" spark plug socket didnt feel like it went all the way on the plug where as a 12 point 5/8" socket that I had did. Maybe the 12 point was a little narrower than the 6 point?? Is that just my sockets and another 6 point one would fit or do I need a 5/8" narrow wall?
Thanks

[1969_Mach1]

Some spark plug sockets are a little deeper than others. Sometimes the tip of the spark plug actually contacts the square end of the ratchet, extension, etc. that is attached to the spark plug socket. Therefore, the socket doesn't go over the spark plug completely. Slip a new spark plug into the socket and be certain this is not the situation so you don't damage a spark plug. Sometimes its simply the rubber insert inside the spark plug socket.

I guess it is possible a spark plug socket can have walls that are too thick to fit into an opening. I haven't come across that situation. Use whichever socket fits the best.

For future, if the condition needs an extension attached to a spark plug socket and no swivel. Using what is called a Wobbly type of extension is safest to prevent accidental damage to the spark plug. The end of the extension is not exactly a square shape allowing a small amount of swivel for misalignment.

Best Regards,
Mike

[Mustangmike]

If I remember correctly, I believe the 12 point sockets may be a little narrower. The reason I say this is I need to use a 12 point when removing the lug nuts of my torque thrust rims. The regular socket is too wide to fit into the cut away on the rim.