5L50E Overhaul Kit, new and ready to install. Fits the 5L50E. Ships fast from the USA.
A Cadillac or BMW with the GM five-speed that now flares between gears, slips when it is hot, or takes a long pause before it engages Drive is usually a candidate for a full rebuild rather than another fluid change. This 5L50E overhaul kit is a complete master-style rebuild set for the 5L40E, 5L50E and 5L51E family, with friction plates, steel plates, valve body and case gaskets, the pan gasket, front and rear seals, O-rings and sealing rings in one box.
GM builds the 5L50E in Strasbourg, France, as the higher-torque sister of the 5L40E. Both use the same five ratios, from 3.42 in first to 0.75 in fifth, but the 5L50E is rated for roughly 311 lb-ft against about 250 lb-ft for the 5L40E, so it went behind the bigger engines and heavier vehicles. Every gear change in this unit is a clutch pack being filled with oil pressure and clamped, and each pack depends on rubber piston seals and sealing rings to hold that pressure. Glazed frictions slip; hardened seals bleed pressure and make good frictions slip. This kit replaces both halves of the problem, so the rebuilt unit is not left with old seals feeding new clutches.
From the product photo, the kit contains full friction and steel sets for the clutch packs, the valve body separator gaskets, the pan gasket, front pump and rear output seals, and the bag of O-rings, square-cut seals and sealing rings for the pump, drums and case passages.
Check fluid level the way the factory procedure calls for, with the engine running and the fluid at the specified temperature; a low level alone can cause flares. Scan the transmission controller for stored codes, then read line pressure using our line pressure testing guide. If pressure is low in every range, look at the pump and for leaks; if it is normal and only one gear slips, that clutch pack has failed. Harsh shifts with clean fluid are often a valve body problem instead, and our slipping diagnosis guide helps you tell them apart.
The kit is made for the shared 5L40E, 5L50E and 5L51E family. According to Transmission Digest, Cadillac used the 5L50E only with the 4.6L engine, and the identification tag sits on the left rear of the case above the pan rail. BMW names the 5L40E the A5S360R and the 5L50E the A5S390R. Because this family went into Cadillac, BMW, Pontiac, Saturn and Holden models over many years, read the tag on your case or send us your year and VIN so we can confirm the kit before it ships. Every part we stock for this unit is on the 5L50E parts page.
Soak every new friction plate in clean fluid for at least 30 minutes before assembly, and check each clutch pack clearance against the service specification as you stack it. Lube sealing rings with assembly gel so they do not roll or cut, and air-check each drum and passage before the case is closed. Clean the valve body while it is apart and fit the new separator gaskets in the correct positions. A new filter belongs with every rebuild; the 5L40E/5L50E filter and pan gasket kit covers it. Inspect the drums and planetary for scoring or worn bushings and replace what is damaged, such as the 5L50E clutch drum. Fill with the ATF your vehicle calls for, BMW or GM specification by application, and reset the controller adaptives so it relearns shift pressure on the new clutches.
| Fits | 5L50E |
| Part type | Overhaul Kit |
| Condition | New |
| 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 kit is built for the 5L40E, 5L50E and 5L51E family. Read the tag on the left rear of the case or send us your year and VIN, and we will confirm before it ships.
Yes. The kit includes friction and steel plates along with the gaskets, seals, O-rings and sealing rings needed to reseal the unit.
Plan on a separate filter. The 5L40E/5L50E filter and pan gasket kit is the match for this rebuild.
Use the ATF specified for your vehicle. BMW and GM applications of this transmission call for different factory fluid specifications, so check your owner manual or service information.
Yes. Reset the transmission adaptive values with a capable scan tool and drive the car through all gears so the controller learns shift pressures for the new frictions.
