AW55-50SN Clutch Drum, used and ready to install. Fits the AW55-50SN. Ships fast from the USA.
This is a used Aisin 4-5 clutch drum assembly for the AW55-50SN and AW55-51SN five-speed transaxle, the unit behind Volvo S60, S80, V70 and XC90 models, Saab 9-3 and 9-5, and the Chevrolet Malibu and Saturn Vue that used the GM version. It comes with both sun gears that ride in this assembly: the 50-tooth 1-2/Reverse sun gear and the 32-tooth 4-5 sun gear. If your rebuild turned up a burned 4-5 pack with a scored or heat-checked drum, or a sun gear with damaged splines or teeth, this replaces the hard parts in one piece so you are not hunting for three separate used components.
The AW55-50SN gets its five forward ratios from three clutches, five brakes and two one-way clutches. Sonnax's apply chart for the family names them: C1 forward clutch, C2 direct clutch, C3 4-5 clutch, B4 third band and B5 1-2/Reverse clutch among them. This drum houses the C3 pack, the clutch named for the two top gears it drives, fourth and fifth. The 32-tooth 4-5 sun gear and the 50-tooth 1-2/Reverse sun gear sit in the same assembly, so the drum is part of the power path in low gears and reverse as well as on the highway. When the C3 piston cannot hold full apply pressure because of a worn seal land, a scored clutch surface or a cracked housing, the pack slips at cruise, cooks its frictions and dumps debris into a valve body that is already the weak point of this design.
A lot of AW55-50SN complaints that feel like slipping clutches start in the valve body. Sonnax's vacuum test guide ties a worn solenoid modulator valve to no 3rd, 4th or 5th, and a worn shift pressure control valve to harsh 3-4 and 4-5 shifts and no 5th. So check fluid level and condition, read codes, and look at line pressure first, using our AW55-50SN service guide for the fluid and valve body checks. Our guide to Aisin slipping under load walks through separating a pressure problem from a mechanical one. If pressure is correct and the unit still slips in fourth and fifth, or the pan is full of lining, pull the unit and air-check the 4-5 piston. Then inspect the drum surface, ring lands and both sun gears.
The listing covers the AW55-50SN and AW55-51SN. The same family is also sold as the AF23 and AF33 and as the Nissan RE5F22A, but the listing does not name those, so do not assume they interchange. This transaxle ran in many brands from 2001 into the late 2000s, and Aisin changed internal parts along the way. Before ordering, count the teeth on your old sun gears (50 and 32 here), compare drum height and spline count, and check the number of plates in your 4-5 pack. If you are not sure, send your year, make and VIN and we will check it. Other parts for this unit are on our Aisin parts page.
| Fits | AW55-50SN |
| Part type | Clutch Drum |
| Condition | Used |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
It is listed for the AW55-50SN and AW55-51SN, used in Volvo models such as the S60, S80, V70 and XC90, Saab 9-3 and 9-5, and GM's Chevrolet Malibu and Saturn Vue. Match your sun gear tooth counts and drum dimensions, or send us your VIN.
Yes. The assembly includes the 50-tooth 1-2/Reverse sun gear and the 32-tooth 4-5 sun gear along with the 4-5 clutch drum.
Plan on new frictions, steels and piston seals. This is a used assembly, and the clutch pack should be renewed and the clearance set during your rebuild.
It depends on the vehicle maker. Volvo and Saab applications call for JWS 3309 type fluid or the later Aisin AW-1 spec on some builds, while GM Malibu and Vue use Dexron VI. Go by the owner's manual or fill label.
Not always. Worn valve body bores and solenoid faults commonly cause a no-5th or harsh 4-5 shift. Check codes and line pressure first, and replace the drum when inspection shows a burned pack, scored drum or damaged sun gear.
