Exhaust Manifold/Winter Summer Paddle

[m-37Bruce]

I screwed up and lost the nut for my Winter/Summer Exhaust Valve. All I wanted to do was replace the nut/star washer.
My problem is nuthing I have seems to fit the stud, does anybody know the size/thread count of said nut?

[ZGjethro]

I pulled my nut off, and as near as I can tell it is a 1/4-27. The 27tpi gauge fit perfectly, but I am guessing at the quarter inch. I cannot find any of my manuals. Should the pointer on the lever be down or forward in the summer?

[m-37Bruce]

Most folks run it in the middle, since we never get any extreme weather swings....except for last week w/triple digit temps. I am relived to get the dimension of said nut!
Thanks 4 Getting Back 2 Me ZG!

[rc51racer]

It's 1/4" 28 and 1/4" 20 on the other end.

http://blog.gieselman.com/post/Dodge-M3 ... ement.aspx

[ZGjethro]

I'd take rc51racer's info over mine. I thought a 27 pitch thread sounded odd.

[rc51racer]

I pulled the info from the parts manual, also verified with a thread guage.

[m-37Bruce]

The boys/mechanix in my repair shop at work told me it couldn't be 27, had to be 28! So that's what I did, already finished up w/ it. Now waiting for my Zenith Carby to make it's way home!
Thanks 4 Everyone's Help,

[WarrenD]

Mine is rotated all the way CCW, the pointer is facing forward to the right. Since I bought it at the end of summer, I'm assuming that's the summer position. Never moved it, truck ran fine this past winter.