5L50E Master Rebuild Kit 2003-10, new and ready to install. Fits the 5L50E. Ships fast from the USA.
The 5L50E is the five-speed automatic GM built in Strasbourg, France, behind the 4.6L Northstar V8 in Cadillac models such as the STS, SRX and XLR, and in BMW form behind several six-cylinder cars. When one of these starts slipping in a single gear, flares on upshifts, or leaves dark, burnt fluid and friction material in the pan, the honest fix is a full overhaul. This master rebuild kit is built for the 5L40E, 5L50E and 5L51E family and gives you the frictions, gaskets and seals for that job in one order.
The 5L40E and 5L50E share the same gear ratios (3.42 first through 0.75 fifth), but the 5L50E is rated for more torque, about 311 lb-ft against 250 lb-ft, and heavier vehicles. That extra load is carried through the same basic layout of clutch packs and planetary sets, so worn frictions and tired seals show up the same way: lost apply pressure, slipping under load, and shifts that get longer as the unit heats up. A master kit replaces the friction material in every pack and reseals the pump, drums and case, so you are not rebuilding one clutch and leaving the next weak link in place.
This family has a complicated valve body, and not every shift complaint is worn clutches. Check the fluid level and condition, scan for stored codes, and if you can, take a line pressure reading. Low pressure across every range points toward the pump or a leak; slipping in only one range with normal pressure points to that clutch pack. Our slipping diagnosis guide and line pressure testing guide cover both checks. If the fluid is still clean and you only have a harsh shift, a valve body or solenoid issue is more likely than worn frictions.
Our listing is for 5L50E units from 2003-2010, and the kit itself is built for the whole 5L40E, 5L50E and 5L51E family. Know which one you have before ordering. Transmission Digest notes that on Cadillac the 5L50E was used only with the 4.6L engine, and that the identification tag sits on the left rear of the case just above the pan rail; the service-parts label also carries the RPO code. BMW calls the 5L40E the A5S360R and the 5L50E the A5S390R. Because these units were used across Cadillac, BMW, Pontiac, Saturn and other brands, match the tag on your case or send us your year and VIN and we will confirm. See every part we carry for this unit on the 5L50E collection page.
| Fits | 5L50E 2003-10 |
| Part type | Master Rebuild 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.
No. The kit is built for the 5L40E, 5L50E and 5L51E family. Our listing is for 5L50E units from 2003-2010. Check the identification tag on the left rear of the case or send your year and VIN to confirm.
On Cadillac, the 5L50E was paired only with the 4.6L engine, and the service-parts label shows the RPO code. BMW lists the 5L40E as A5S360R and the 5L50E as A5S390R.
A new filter and pan gasket, any drum or bushing that shows wear, and the torque converter should be serviced or replaced if the old unit failed and contaminated the fluid.
Use the fluid specified for your vehicle. Cadillac and BMW applications call for different specifications, so check the owner's manual or service information before filling.
Only if worn clutches or leaking seals are the cause. Valve body and accumulator problems are common in this family, so check codes and line pressure first.
