6L45 Shift Kit 2006, new and ready to install. Fits the 6L45. Ships fast from the USA.
A BMW 1, 3 or 5 Series, X3, Cadillac ATS or CTS with the small GM six-speed that hesitates before it drops into Drive or Reverse, then lands with a bang, or one that has started logging gear ratio and pressure control codes, usually has a line pressure problem before it has a clutch problem. This listing is the TransGo SK 6L80 Shift Kit. The part number says 6L80, but TransGo's application covers 2006-on 6L45, 6L50, 6L80 and 6L90, so it fits the 6L45 (GM RPO MYA, BMW GA6L45R) directly. It is a repair kit that restores the regulating circuits, not a hard-shift calibration.
The 6L45 shifts clutch to clutch. Its control module sits on the valve body and moves clutch regulator valves through pressure control solenoids, so every shift depends on two supplies being steady: line pressure from the pressure regulator (PR) valve in the pump, and the regulated feed the solenoids work from. On a 6L45 both have known wear spots. The PR valve wears its bore in the pump body, and the solenoid regulator valve wears its bore in the valve body. Once either leaks, the module commands one pressure and the clutch gets another.
TransGo's fix drops in without reaming. A hardened steel PR valve with longer end lands seals in a worn pump bore, and one land is purposely undersized to add lube flow, which TransGo says helps stop engine chug when coasting to a stop hot. A new boost valve and bushing carries a small ball-and-spring relief that caps line pressure spikes. The solenoid regulator valve gets a new steel valve running in its own bushing. The kit also has five pressure switch diaphragms and seals, plus three sealing rings with expander wires for pump stators that use rotating rings.
Every one of those codes can also come from a worn clutch pack or a sticking solenoid, so they are a reason to test, not a diagnosis.
Check the fluid level first, using the factory hot-check method, since a low 6L45 gives many of the same complaints. Then put a gauge on the line pressure port and compare it with the commanded pressure on a scan tool. Sonnax notes that a pressure stuck flat at roughly 60 to 68 psi points to a line pressure solenoid stuck in exhaust, which this kit will not fix. Pressure that wanders, or overshoots on a throttle stab, is what a worn PR or boost circuit looks like. Our 6L45 limp mode guide walks through the code and pressure checks, and the harsh shift guide covers the same family's other causes.
TransGo lists this kit for 2006 through 2020 6L45 through 6L90 units. The year 2006 on this listing comes from that application line: the 6L80 launched first, in the 2006 Cadillac STS-V, and the smaller 6L45 followed in later BMW applications and in the Cadillac ATS and CTS. So this kit covers the 6L45 from its first production on. GM upper valve bodies are unique by RPO, but this kit only replaces valves and pressure switch parts, so the RPO matters for other repairs, not this one. If you are unsure your car has a 6L45, send us the year and VIN before ordering. More parts for this unit are in our 6L45 collection.
The PR valve parts go into the pump, so the unit has to come apart. Re-use the original bumper spring with the new red PR spring; TransGo says both must be used with the new valve. Only fit the supplied stator rings on a steel ring groove with rotating rings. Do not use them on aluminum grooves or on stators with locking notches. In the valve body, the top of the new gold retainer must sit below the casting surface. Measure the check balls while it is apart, because undersized balls can cause no forward or no reverse. If the pump bore is past saving, or you want new rotor and slide parts, see our 6L45 pump repair kit. A badly worn valve body may be better replaced with a remanufactured 6L45 valve body. GM applications fill with DEXRON-VI; BMW units take the fluid BMW specifies for that transmission.
| Fits | 6L45 2006 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. TransGo builds the SK 6L80 for the whole GM six-speed rear-drive family and lists it for 2006-on 6L45, 6L50, 6L80 and 6L90. The PR valve, boost valve and solenoid regulator parts are common across the four units.
Not by design. It restores the pressure regulator and solenoid regulator circuits to work as they should and caps pressure spikes. It is a repair kit, not a firm-shift kit. Shift feel should go back toward factory.
For the full kit, yes. The pressure regulator valve, boost valve and stator rings are in the pump, so the pump has to come out. The solenoid regulator and pressure switch parts are in the valve body and control module.
Only if worn PR or solenoid regulator bores caused it. A line pressure solenoid stuck in exhaust, a failed control module or burned clutches need their own repairs. Test line pressure against the commanded value before you buy.
GM vehicles use DEXRON-VI, checked hot by the factory level-check method. BMW vehicles use the fluid BMW specifies. Clear adaptive values with a scan tool after the repair, then drive through all the gears so the module can relearn.
