Ford AOD cooling line thread size

[IC2]

I am installing a 1988 Ford 5.0 with an AOD in my 32 Ford. Starting to install a remote tranny cooler and looking for help on what size thread is in the tranny case. A 1/4 NPT seems to go in finger OK tight but I am not totally sure this is the correct thread to use. Any help will be appreciated.
Thanks

My recollection is that most of these are 1/8" NPT, though many Fords of this vintage had whatever worked that day for many 'odd' parts.

[rspears]

I think they had 5/16" push lock fittings from the factory, but many leaked and had a Ford OEM adapter installed later - http://www.latemodelrestoration.com/...Line-Connector
I don't recall the size, but if your 1/4npt goes in finger tight and stops before it bottoms out I would bet that is the right fitting.

[roadster32]

All Ford auto's use 1/4" NPT threads in the case

[32steel]

All Ford auto's use 1/4" NPT threads in the case

Thanks for confirming what I suspected. As I said in my post I can thread in a 1/4 NPT fitting finger tight, did not want to tighten it in place if it was was not the correct match for the threads.

There is a huge difference between an 1/8 NPT and 1/4 NPT and no way could be confused to have been an 1/8 NPT. The threads are fine and there is no need to chase the threads, that is the last thing I would want to do and run the risk of putting crud or possibly chips in the tranny.

[roadster32]

Dave i believe the only boxes that use 1/8" NPT is the Torqueflite & the Powerglide.

My recollection is that most of these are 1/8" NPT, though many Fords of this vintage had whatever worked that day for many 'odd' parts.

[IC2]

Dave i believe the only boxes that use 1/8" NPT is the Torqueflite & the Powerglide.

Steve - My two C4's have 1/8NPT. I even had to buy a new tap to chase them as all my NPT's were 3/8 and up. But, like I said above, Ford made lots of interesting parts in the '60 through the '80s.

[roadster32]

Dave i've worked with C4's all my life but never seen one with 1/8" NPT threads.

Steve - My two C4's have 1/8NPT. I even had to buy a new tap to chase them as all my NPT's were 3/8 and up. But, like I said above, Ford made lots of interesting parts in the '60 through the '80s.

[IC2]

Dave i've worked with C4's all my life but never seen one with 1/8" NPT threads.

Oh well - no big deal. If the OP can use a 1/4" NPT to chase the threads, then the 1/8"NPT will just rattle in the hole or the 1/4" wont fit if it's the other way

And as far as C4's yep, had a few apart myself

[IC2]

Dave i've worked with C4's all my life but never seen one with 1/8" NPT threads.

Steve - this is my 1/8-27npt purchased especially for chasing C4 cooling lines and used for a total of 4 holes on currently owned transmissions: