4R70W Clutch Drum 1993-2008, remanufactured and ready to install. Fits the 4R70W. Ships fast from the USA.
Tearing down a 4R70W out of an F-150, Expedition, Crown Victoria, Grand Marquis, Town Car, Mustang or Navigator and finding a cracked drum, stripped splines or a burnt clutch pack? This is a remanufactured 4R70W clutch drum listed for the full 1993-2008 production run. It lets you rebuild around a sound drum instead of reusing a casting that already failed once.
The 4R70W is a four-speed rear-drive overdrive automatic with three rotating clutch drums. The forward drum rides on the input shaft and applies the forward clutch in first through third. The direct clutch drum is driven by the intermediate stub shaft and applies the direct clutch for third and fourth. The reverse/overdrive drum at the front carries the reverse clutch, and the overdrive band wraps around its outside. Each drum holds a clutch pack, a piston and a return spring, and each one has to hold pressure through its sealing rings and bushing surfaces. If a drum cracks or its sealing surfaces wear, apply oil leaks away, the pack slips and burns, and the rest of the unit fills with debris.
Two of these drums are known weak spots. Sonnax calls forward drum breakage a chronic problem across the AOD, AODE and 4R70W series. Sonnax also documents the original direct drum stripping its splines and the intermediate stub shaft breaking, which is why it sells one-piece drum and shaft kits for this family.
A drum rarely fails alone. Low line pressure and cross leaks burn clutch packs, and a new drum will not survive the same fault. Transmission Digest reports that on 2001-and-later units Ford dropped the two-bolt stiffener plate under the 2-3 accumulator, which lets forward clutch oil leak into the direct circuit and drag the direct clutch. Check pressure and inspect the valve body before you replace hard parts. Our 4R70W 3-4 clutch failure guide covers the direct clutch side, and the 4R70W F150 common problems guide lists the truck-specific faults to rule out.
The listing covers the 4R70W from 1993 to 2008. Ford revised this unit several times in that span: ATRA notes that forward drums changed from one apply hole to three in 2004, that a turbine speed sensor was added, and that the intermediate diode was redesigned in 2007. Because this one listing covers the whole run, set your old drum next to the product photo. Compare the drum type, spline count, sealing ring lands and overall height before you install it. If you are not sure which drum you need, send us your year and VIN. Other 4R70W hard parts are in the 4R70W parts collection.
| Fits | 4R70W 1993-2008 |
| Part type | Clutch Drum |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The listing is titled as a 4R70W clutch drum for 1993-2008 and does not name the drum position. Compare the photo with the drum you removed (spline count, height and sealing ring lands), or send us your year and VIN and we will check it before it ships.
ATRA says the forward drum changed from one apply hole to three in 2004 and calls that change cosmetic. Later units also added a turbine speed sensor that reads the forward drum through a non-magnetic sun shell, so match your drum to your year. If in doubt, ask before installing.
Replace the frictions, steels, piston seals and sealing rings for that pack, the filter, and any worn bushings. On a direct drum failure, inspect the intermediate stub shaft too. Sonnax treats the drum splines and stub shaft as a matched weak point.
Common causes are low line pressure and forward-to-direct cross leaks. On 2001-and-later units, Transmission Digest traced the cross leak to the deleted stiffener plate under the 2-3 accumulator. Fix the hydraulic cause or the new clutches will burn too.
Use MERCON V. Do not use MERCON LV or ULV, which Ford says are not substitutes where MERCON V is specified.
