Gary, question 81 rear.
Tech Contributor
Joined: Aug 1999
Posts: 15,173
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From: Connecticut, USA
If you are calling on me, I can't help with that one. I only work on the 63-79 iron units. With them I tap the housing 1" beyond the strut bracket pad. It puts the hole in a low spot in the diff and works good.
If you do tap a hole, I would use a 1/4 x 1/8 npt brass bushing instead of a straight plug. constant use may strip out the threads in aluminum but holding the 1/4 npt bushing and removing the 1/8 plug will not stress the aluminum and give you long life. I did this with my Muncie 30 years ago and haven't had a problem since.
If you do tap a hole, I would use a 1/4 x 1/8 npt brass bushing instead of a straight plug. constant use may strip out the threads in aluminum but holding the 1/4 npt bushing and removing the 1/8 plug will not stress the aluminum and give you long life. I did this with my Muncie 30 years ago and haven't had a problem since.
Thread Starter
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
If you are calling on me, I can't help with that one. I only work on the 63-79 iron units. With them I tap the housing 1" beyond the strut bracket pad. It puts the hole in a low spot in the diff and works good.
If you do tap a hole, I would use a 1/4 x 1/8 npt brass bushing instead of a straight plug. constant use may strip out the threads in aluminum but holding the 1/4 npt bushing and removing the 1/8 plug will not stress the aluminum and give you long life. I did this with my Muncie 30 years ago and haven't had a problem since.
If you do tap a hole, I would use a 1/4 x 1/8 npt brass bushing instead of a straight plug. constant use may strip out the threads in aluminum but holding the 1/4 npt bushing and removing the 1/8 plug will not stress the aluminum and give you long life. I did this with my Muncie 30 years ago and haven't had a problem since.
