Transmission Adapter Fittings to AN — Sold as a Pair

Convert factory transmission cooler ports to clean, serviceable AN male for braided PTFE AN lines. These adapters use 1/4-18 NPSM straight thread and seal at the case seat/washer (not the threads) for a durable, leak-resistant interface in high-heat ATF service.

What’s included

2 × transmission adapter fittings (pair) — choose AN-6 or AN-8
2 × sealing washers — the washer/seat does the sealing (threads do not)

For 4L70E/4L80E/4L85E: the rear port requires the long/nipple adapter to reach the internal seat. The front port is standard depth. Use the selector above to match your case.

Add PTFE AN Hose Ends (AN-6/AN-8) Add PTFE Hose Bundles (AN-6/AN-8) Add Clamps & Mounting Hardware Add Install Tools

Choose your transmission & case port

Transmission	Case Port Thread / Depth	AN Male Options	Notes
Ford C5 / AOD / AODE / 4R70W	1/4-18 NPSM • standard depth	AN-6 or AN-8	Threads do not seal; washer/seat does
Ford E4OD / 4R100	1/4-18 NPSM • standard depth	AN-6 or AN-8	Common retrofit to AN lines
GM TH350 / TH400	1/4-18 NPSM • standard depth	AN-6 or AN-8	Standard GM case thread
GM 200-4R	1/4-18 NPSM • standard depth	AN-6 or AN-8	Common retrofit to AN lines
GM 700R4 / 4L60E / 4L65E	1/4-18 NPSM • standard depth	AN-6 or AN-8	Standard-depth front & rear ports
GM 4L70E	1/4-18 NPSM • rear port requires long/nipple	AN-6 or AN-8	Front port standard depth; rear uses long/nipple for seat reach
GM 4L80E / 4L85E	1/4-18 NPSM • rear port requires long/nipple	AN-6 or AN-8	Rear port is deep/stepped; long nose reaches internal seat
GM Powerglide (select cases)	1/4-18 NPSM or 1/4-18 NPT (case-dependent)	AN-6	Verify NPSM vs NPT before ordering
GM 6L80E / 6L90E / 8L90E	OE thermostat block retained or replaced	AN-6 or AN-8 (via adapter block)	Retain OE block or install an AN adapter block

Note: Year/casting can vary. Always verify your port depth and choose the long/nipple option where specified.

Direct conversion: thread into the case and transition to AN in one move—no stacks of fittings.
PTFE compatible: pairs with Hot Rod AN PTFE hose & ends for ATF heat and chemical resistance.
Flow-smart sizing: AN-6 suits most builds; upsize to AN-8 for heavy towing/high-HP cooler circuits.
CNC-machined, anodized aluminum: durable finish—use aluminum AN wrenches to protect it.

Install tips:

NPSM ports: sealing occurs at the seat/washer—no thread sealant on NPSM threads.
4L70E / 4L80E / 4L85E: rear port requires long/nipple; front port is standard depth.
Tighten to seal: snug until the washer contacts, then add ~1/8 turn; re-check after first heat cycle.
Route lines away from headers/exhaust. Use isolator clamps to prevent vibration wear.
PTFE hose tip: wrap the cut area tightly with tape before shearing; remove tape after seating the olive/ferrule. See our install guide.

Important: For transmission cooler circuits. Not for brake or power steering systems.

Specs

Case side	1/4-18 NPSM (straight) — seal at seat/washer
Line side	AN-6 or AN-8 male (37° flare)
Includes	Sealing washers (2)
Material/finish	CNC-machined aluminum, anodized
Primary use	Transmission cooler lines (ATF)