FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Stangman on May 31, 2026, 12:05:10 PM
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So I got a different tranny and I’m using AN fittings that screw into tranny. My old c6 tranny had I believe 1/8 inch NPT fittings that screwed in to it. I just went to put fittings in and the hole is twice as big and course thread and it has a bevel like the fitting would screw in with an O ring that would seal it. Anybody come across this. And if you did what fitting do you have. I’m using #4 lines but that’s really irrelavent I need the side that goes in tranny. Can’t use an adapter on rear one because there’s no room when tranny is in its proper location it will hit tunnel.
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I believe not a 100% sure but I think the c-4 and c-6 used a 1/8 nps straight pipe not npt
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C6 used 2 different fittings over the years.
Depends on application. ie; what vehicle.
"Most" C6's had 1/8 NPT pipe to 5/16 inverted flare,
but I have seen T-Birds with 3/8 line inverted flare.
Some trucks too.
The 3/8 fittings used 1/4 straight pipe thread in the case, and either an O-ring OR a tapered seat.
"Some" 5/16 line fittings also used the 1/4 straight pipe thread in the case.
C4's I "think" all had 1/8 straight pipe and a fitting that used an O-ring at the case.
Your C6 "probably" has 1/4 straight pipe that uses an O-ring at the case.
Pics would help.
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Thanks for clarifying that
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Thank you was inshore if I needed O ring or flair. I’m gonna get something tomorrow I will let you know. It looks like there’s a lot of fittings that will work but it would have been nice if someone had a part number they used.
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I do have pics but don’t know how to put them on here
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I haven`t had a C6 in many years, but I seem to recall that the earlier versions used a straight thread with a gasket, and 3/8" tubing, and later versions had NPT a 5/16" tubing. And my C6 in my old 428 CJ Mustang had an oddball rear fitting, that was 90 degrees, with a sealing nut and O ring.
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So I talked to Jay Broader and he told me to use a 1/4 NPT fitting. So I’m gonna try it. My other tranny I used an NPT fitting and it was fine for 15 years so I won’t be ripping it in there but should be fine. There must be a special fitting for it though. Even if these fittings work I’m gonna eventually get the right fitting.
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If you have a tgransmission rebuilder shop in your area just stop by and ask them what they use.
Greg
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Looks like it’s a fragola fitting. 181671-bl. I’m ordering 2. Just punched that number in nd it says 1/8 inch thread. Sometimes it’s a 1/4 inch. There’s a couple of places to call that show it as the one I want. Dynamic transmissions and Lyons performance. I’m gonna get it.