Question RE TH400 fluid cooler lines

Old May 29, 2025 | 09:42 AM
  #1  
acavagnaro's Avatar
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Question RE TH400 fluid cooler lines

1969 442 with Turbo 400. Has the 5/16" hard lines carrying fluid to-and-from the radiator. Long story, but I'm afraid I may have stripped the threads re-installing one of the lines into the 1/2-20 inverted flare fitting mounted in the trans case casting. How are these two hex fittings captured in the case casting (passenger side)? I'm assuming since they're a hex feature they're threaded in but maybe the hex is only there to assist with installation of the line fitting. Since I may have to remove/replace one of them, I'd like to know how it's captured in the cast housing so I don't risk a bigger problem by damaging something else just trying to get it out! Thanks in advance.

BTW, tried to upload a jpg of the fittings I'm talking about just for convenience and the system apparently doesn't want to allow it. Never had that problem before.
Old May 29, 2025 | 09:59 AM
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The case is 1/4-18 NPSM straight thread and use a copper or PTFE washer
Old May 29, 2025 | 10:07 AM
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Here are the replacements.


Old May 29, 2025 | 10:14 AM
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Old May 29, 2025 | 10:28 AM
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The 1973 and later transmissions used NPT thread at the case, the earlier ones are straight thread with a washer.
Old May 29, 2025 | 11:58 AM
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awesome - thanks, guys!
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