MC_Liberty

Hi,

I'm in the process of upgrading my transmission plumbing to elastic pressure hoses, and I need some assistance regarding the thread size of the thermostatic valve on a 4R75W automatic transmission. From what I've gathered, it seems to be metric, possibly M10, but I'm not entirely certain. Unfortunately, I'm unable to check it out firsthand right now.

Before I proceed with ordering the hoses, I want to ensure I have the correct specifications. Can anyone confirm the thread size of the thermostatic valve? Your insights would be greatly appreciated!

Thanks in advance!


Valve photo: https://imgur.com/a/OKvNqWE

Chinatown Boy

Are you talking about the cooler bypass valve?

MC_Liberty

Yes

manicmechanic007

It is a metric pipe thread
Not certain of the pitch or diameter
Most likely a M14 x 1.0
Remove it and hit a nut and bolt supply house and they can get you the fittings

Nun Ya

IIRC, they are 1/2"-20 inverted flare fittings. You can pick one up at any auto parts store for a couple bucks and test fit it to your valve to make sure that's correct before ordering your adapters.

MC_Liberty

Thanks for the responses. I have another query: Does anyone happen to know the thread size of the cooler line fittings in a transmission oil cooler? I've discovered that in the radiator, it's a metric thread - M18 1.5. However, due to severe rust on the lines, attempting to unscrew the fittings might result in damaging them beyond repair.

Any insights into the thread size of the cooler line fittings would be greatly appreciated. I'm trying to gather all the necessary information before proceeding with any further actions.


I forgot to mention that it's for an Expedition, not an F150. I'm uncertain if the coolers on these two models share the same specifications. While researching, I came across aftermarket units with 3/4-16 inch inlet and outlet threads, but I'm unsure if this applies to the OEM version. Looks a little strange, metric and inch threads in one system... but I'm not an engineer.

Thank you for your assistance!


Expedition cooler: