trans temp gauge sending unit
I do not believe that the port is a straight thread. I am pretty confident that it is 1/8 27npt if I remember correctly. Ill have to check to confirm this but it is definitely a npt. The reason for this is because the pressure ports in transmissions need to seal and most do not use any sealant. Vince
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
Ah ha my mistake, I remember that the coolant line threads are not NPT. Now I remember, the coolant fittings are a straight thread. I have heard those will crack by trying to install an NPT. I could tell if I ever pulled my port plug out one day.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Here's an excerpt from an ebay ad:
People have been asking us to run our GM trans fittings in -8AN. Ok, here they are!
-8 x 1/4NPS is the correct size for GM turbo 350, Turbo 400, 700R4, 4L60E and many other GM transmissions. These have a straight thread and seal on the gasket. Unlike a tappered pipe thread these will not crack the case.
They are 1/4 NPS which is a straight thread. I assumed the pressure port was the same bc of the crack case problems.
People have been asking us to run our GM trans fittings in -8AN. Ok, here they are!
-8 x 1/4NPS is the correct size for GM turbo 350, Turbo 400, 700R4, 4L60E and many other GM transmissions. These have a straight thread and seal on the gasket. Unlike a tappered pipe thread these will not crack the case.
They are 1/4 NPS which is a straight thread. I assumed the pressure port was the same bc of the crack case problems.
