Q's re M22 transmission magnetic fill/drain plugs

[Wayne M.]

Here's 2 sets of plugs out of a couple of rock crushers that I have. It appears that there is an early / late design. Ones on left seem to be the same as those in a pic of that 1965 M22 tanker (Colvin's appendix to '65-69 Chev by the numbers). The magnets on the latter type are stronger.

Questions are: were drain plugs after the introduction of the "661" case in 1970 all magnetic (M22, M21, M20) ? What about the fill plugs; would they also be magnetic type ?

Do your observations confim the approximate design change on the right on M22s sometime later in 1969 ?

[Joe L.]

Re: Q's re M22 transmission magnetic fill/drain pl

Wayne-----

I have 2 NOS '661' main cases. Both were supplied with with Lisle magnetic plugs like the ones shown to the right and these plugs were used at both drain and fill locations. Just what was used in PRODUCTION, I cannot say for sure; one never knows regarding originality of transmissions observed in the field for easily changed parts like these. However, I strongly suspect that it was the same as the SERVICE cases I have.

I believe that the magnetic drain and fill plugs replaced the epoxied-in case magnet of earlier years. So, while they were probably a somewhat expensive item, they were probably a lot less expensive than the epoxied-in magnet. That epoxied-in magnet has always worried me, too. If that thing should ever get loose, you know exactly where it's going to go IMMEDIATELY.

[Warren F.]

Re: Q's re M22 transmission magnetic fill/drain pl

Wayne,

My plugs look like the ones on the right as well for both of my '71 LS6 coupes with M22's

[Wayne M.]

Thanks guys -- addendum

So I guess all I can deduce is an early / late difference in cofiguration.

The two-pronged (early ?) design has a weaker magnetic field, at least on these two. But the surface area is more than double that of the later ones. As a result, I found much more magnetic sludge on the plugs of the early design. I realize this isn't very scientific, as it could be due to the different state of wear, previous maintenance etc.