4L30E Shift Kit 1991-2004, new and ready to install. Fits the 4L30E. Ships fast from the USA.
If your BMW 3 or 5 Series, Isuzu Rodeo or Trooper, Honda Passport or Cadillac Catera keeps burning the band, cuts loose on the 2-3 shift, or slips in 1st and 2nd, the 4L30E behind the engine has a known oil-feed problem. This is the TransGo SK 4L30E, a repair kit for 1991-2004 units that fixes the cause during an overhaul rather than just firming up the shift.
Most shift kits are springs and separator plate changes. The 4L30E kit is different because the problem is different. TransGo's instructions center on the support bushing that feeds the 3rd (direct) clutch drum. The kit includes a new TransGo support bushing and a driver to press it in; its small hole must line up with the small feed hole in the support, and the 3rd drum shaft has to turn freely in it. A worn bushing leaks that feed, which starves the direct clutch and drags the band. The kit also supplies a tapered pump alignment tool so the pump is centered on the converter hub before the center bolts are torqued to 15 ft-lb, and it has you enlarge two separator plate holes, marked A and B, to .110 in the location that matches your plate type.
TransGo also explains why 3rd and 4th can slip on a worn unit: band apply pressure stays on in 3rd and 4th, and release oil above the servo is what pushes the band off. A worn servo pin bore leaks that release oil, so the band drags in 3rd and 4th and wears out early.
GM's 4L30E specification sheet shows a line pressure tap, so put a gauge on it as described in Checking Transmission Line Pressure to tell low pressure from a mechanical leak. Rule out electrical faults too: the 4L30E uses two on-off shift solenoids, a force motor for line pressure and a TCC solenoid, and a bad one mimics a hydraulic problem. Our solenoid test guide walks through it. Transmission Digest also notes that a leaking TCC solenoid can cause neutral in reverse on these units.
TransGo lists this kit for 1991-2004 Isuzu, BMW and Cadillac 4L30E transmissions, which also covers the Honda Passport and Acura SLX that used the Isuzu unit. The separator plate comes in a BMW type and an Isuzu type, and the instructions show which two holes to open on each. Do not drill any new holes. Pumps differ as well: PWM-type pumps have no orifice capsule in the nose of the input shaft and need a woven carbon lining converter, while non-PWM units use the capsule and a paper lining converter. TransGo warns that the computer's programming matches the pump and converter type, so do not mix parts between versions. Send your year and VIN if you need us to check, and see our hard parts section for other 4L30E components.
| Fits | 4L30E 1991-2004 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Ships | From the USA |
| Warranty | 1-year |
TransGo lists 1991-2004 Isuzu, BMW and Cadillac 4L30E units. The Passport and SLX used the Isuzu 4L30E. Match the separator plate type (BMW or Isuzu) using the instruction sheet.
No. The support bushing and pump alignment steps require the transmission out and apart, so plan it with an overhaul.
TransGo explains that release oil above the servo pushes the band off in 3rd and 4th. A worn servo pin bore leaks that oil, so the band drags and 3rd or 4th can slip. Check the bore during the rebuild.
TransGo warns against it. PWM units use a woven carbon converter and no input shaft orifice capsule; non-PWM units use the capsule and a paper converter, and the computer programming matches the type.
GM's specification sheet lists Dexron III and about 7 quarts dry with the 245 mm converter. Some BMW applications specify their own fluid, so check your manual.
