AT540 [71-UP] Automatic Transmission Filter (Flat Brass Screen) (400 Type )

When a TH400, 3L80 or AT540 automatic transmission needs an Automatic Transmission Filter replacement, having the correct 400 Type unit on hand means the job moves forward without delays hunting down the right part. What sets this listing apart from multi-piece kits is its simplicity: one Automatic Transmission Filter, one application, nothing else bundled in to raise the price or create confusion about what you are actually receiving.

The Automatic Transmission Filter is cataloged under the AT540 model reference and covers TH400, 3L80 and AT540 units from 1965 onward. That range spans decades of production, so the part sees wide use in both restoration work and routine service. The 400 Type designation refers to the pickup configuration specific to these units; using an Automatic Transmission Filter with the wrong pickup geometry affects fluid flow at the valve body, which is exactly what this replacement is meant to correct.

This is a single-piece shipment. There is no gasket, no pan bolt set, no seal, and no secondary component inside the box. Technicians who already have those items on the bench or who are sourcing them separately will find this listing fits that workflow cleanly. If you need a complete gasket and Automatic Transmission Filter combination, check that the other listing in the catalog matches before ordering both.

The Automatic Transmission Filter ships at 1 lb and is verified against its part record before it leaves. Confirm the unit code on your transmission reads TH400, 3L80 or AT540 and that the build year falls at 1965 or later before placing the order.

• Skip the parts chase: this Automatic Transmission Filter fits TH400, 3L80 and AT540 units and ships as a single ready-to-install piece, no sorting required.
• This listing covers the Automatic Transmission Filter only. It does not include a gasket, seal, pan hardware, or any other component. Verify your full parts list before ordering.
• The 400 Type Automatic Transmission Filter design matches the internal pickup geometry of TH400, 3L80 and AT540 housings, keeping the fit consistent across all three unit codes.
• Contents: one Automatic Transmission Filter, 400 Type, weighing 1 lb. No additional pieces are packed in the box.
• Before ordering, confirm the unit code stamped on your transmission matches TH400, 3L80 or AT540 and that your application falls within the 1965-and-up build range.

What's in the box

• 1 x Automatic Transmission Filter, AT540 [Flat Brass Screen] [400 Type]

Compatible vehicles

• Fits B50 2 Ton School Bus [71-72], C3500 1 Ton - Pickup [88-00], C3500HD 1 Ton Truck [91-02], C40 1 1/2 Ton Truck [71-79], C80 2 1/2 Ton Truck [71-79], F80 2 1/2 Ton Tilt Cab [71-79], K3500 1 Ton 4WD - Pickup [88-00], P4T042 Stripped Chassis [80-84], P6S042 Stripped Chassis [91-96], P6T042 Stripped Chassis [83-90], R3500 1 Ton - Pickup [88-91], S50 1 1/2 Ton School Bus [73-79].