4L30E Master Rebuild Kit, new and ready to install. Fits the 4L30E. Ships fast from the USA.
A 4L30E that slips between gears, flares on the 2-3 shift, takes forever to pick up reverse or has burnt fluid and friction dust in the pan is past the point where a solenoid or a fluid change will save it. This master rebuild kit is for the four-speed GM 4L30E found behind the BMW 3 and 5 Series six-cylinders, the Isuzu Trooper, Rodeo, Amigo and VehiCROSS, the Honda Passport, the Acura SLX and the Cadillac Catera. It is the set you buy when the transmission is coming out and every clutch pack, seal and gasket is getting renewed in one pass.
The 4L30E is built in two halves. GM's own specification sheet shows an adapter case up front that holds the oil pump, an overdrive roller freewheel, the overrun clutch and the overdrive carrier, bolted to a main case that holds the reverse, 2nd, 3rd and 4th clutch packs, a sprag freewheel, one band with its servo, the center support and a second valve body. That is five clutch packs, a band and two valve body gasket sets to replace, which is why a piecemeal rebuild of this unit gets expensive fast. A master kit puts the frictions, steels, lip and lathe-cut seals, sealing rings, gaskets and filter in one box. The kit pictured also shows a band and bushings; check the contents against your teardown before you order extra hard parts.
Rule out the cheap fixes first. Check fluid level hot and smell it, pull the pan and look at what is on the magnet and in the filter, and read codes with a scan tool. A single bad solenoid can mimic a mechanical fault on this unit; Transmission Digest documents a leaking TCC solenoid causing a cold neutral-in-reverse that clears up warm, so test the TCC solenoid before condemning the clutches. Our transmission slipping diagnosis guide walks through the line-pressure and stall checks that separate a hydraulic problem from worn frictions. If the pan is full of debris, compare the cost of a rebuild against a swap with our rebuild vs replace vs reman breakdown.
This listing is for the 4L30E and does not name a specific year range. The 4L30E ran from about 1990 into the early 2000s across several makes, and the parts that differ between makes are exactly the ones a rebuilder handles: Transmission Digest warns that the adapter case, the center support housing and the spacer plate between them vary by manufacturer and do not interchange, even when they look alike. Frictions and steels are common, but gaskets for those joints must match your case. Before ordering, read the identification tag on the case, note whether the transmission is in a BMW, an Isuzu-built SUV or a Catera, and send us the year and VIN if you want the kit checked against your unit.
Browse every 4L30E part we carry, from solenoids to the filter and pan gasket kit, and ship the full job from the USA in one order.
| Fits | 4L30E |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
The 4L30E was used in BMW 3 Series, 5 Series and Z3 six-cylinder models, the Isuzu Trooper, Rodeo, Amigo and VehiCROSS, the Honda Passport, the Acura SLX and the Cadillac Catera. Check the tag on the case to confirm you have a 4L30E before ordering.
The clutch packs are shared, but the adapter case, center support and the spacer plate between them differ by manufacturer and do not interchange. Send us your year and VIN so we can confirm the gaskets in the kit match your case.
Inspect and replace as needed: bushings, the oil pump if it is scored, the TCC solenoid (a leaking one causes reverse problems on this unit), and the filter and pan gasket at the next service. A shift kit is worth adding if the vehicle tows.
The two usual causes are a mismatched adapter case, center support or spacer plate from a different manufacturer, and a worn seal surface on the reverse clutch piston that eats the new lathe-cut seal. Check both during the rebuild.
GM's specification sheet lists Dexron III fluid and a dry capacity of about 7 quarts with the 245 mm converter. Fill, run the engine, and check the level hot on your vehicle's procedure.
Yes. The 4L30E adapts its shift pressure, so clear the adaptive values with a scan tool where your vehicle supports it and drive through all shifts gently while it relearns.
