4L30E Banner Rebuild Kit 1996-2019

An Isuzu Rodeo, Trooper, Amigo or Axiom, a Honda Passport, or an Acura SLX with the 4L30E that slips in second or third, bumps hard into gear, or will not back up after it sits overnight is a common sight at Isuzu-friendly shops. This banner rebuild kit is the Isuzu-pattern rear-drive version: a transmission overhaul kit plus a standard set of friction clutch plates. It is listed without the overdrive piston.

What the banner kit does in an Isuzu 4L30E

The Isuzu units use the same GM 4L30E core as the BMW and Cadillac versions but with a lower first gear. Wikipedia lists the Type B Isuzu ratios as 2.86 first, 1.62 second, 1.00 third and 0.723 fourth, against 2.40 first on the Opel and BMW Type A. Behind the pump, an overdrive section feeds a main case with the second, direct and fourth clutches, a band and a reverse clutch, each held by a piston and sealed by parts in this kit. Lower gearing and towing loads put more heat into these packs, so a worn Isuzu unit usually has tired frictions and hardened seals together.

Symptoms on Isuzu and Acura SLX units

• Slip in second or third under load that gets worse with heat
• Delayed reverse, or no reverse at all on 2000-and-later trucks
• Flare on the 1-2 or 2-3 upshift after a long climb or tow
• Burnt fluid and friction material on the pan magnet
• Leaks at the front seal, the overdrive case joint or the pan

How to confirm it before you buy

Not every slip on these trucks is worn clutches. Transmission Digest reports thin case joint gaskets tearing and causing second or third gear slip, and that is fixed with the gaskets in this kit. On 2000-and-later Isuzu and Honda units, Transmission Digest explains that a reverse block-out valve in the center support is stroked by TCC solenoid oil, so a TCC solenoid that sticks on can block reverse on a healthy unit. The same article covers the round and square case connectors swapping places in 2000 and brittle connector legs that let the internal harness plug in wrong. Test the 2000-up TCC solenoid and check the harness first, then follow the pressure and stall checks in our slipping diagnosis guide.

Fitment

The listing is for the 4L30E rear-drive transmission and names the Acura SLX, and lists a 1996-2019 range. That range is wider than the transmission ever ran: Wikipedia lists 4L30E production through 2004, with the 1996-2000 SLX, 1990-2002 Trooper, 1991-2003 Rodeo, 1998-2000 Amigo, 1999-2001 VehiCROSS, 2002-2003 Axiom and 1994-2001 Honda Passport among the Isuzu-built applications. Treat it as a kit for those trucks, and lay the new gaskets over the old ones at teardown to confirm the match. Read the ID tag, have your year, make and VIN ready, and send them to us to confirm. More 4L30E kits are on our rebuild kits page.

Install notes

• Use every joint gasket in the kit and do not reuse the thin case gaskets; a torn one is a known second and third gear slip.
• The overdrive piston, steels, band and filter are not included. Inspect the steels and band lining, and replace the piston if its molded seal is cut.
• Set clutch clearances with the steels you are installing and air-check each circuit before the valve bodies go on. A worn valve body or pressure control solenoid will undo the rebuild, so test the 2000-up pressure control solenoid while it is apart.
• Fill with Dexron III-type fluid, or the fluid named in your owner's manual, check the level hot, and drive the truck through all four gears so the TCM can relearn. See our adaptive relearn guide.

Does this kit fit my 2001 Isuzu Rodeo or Honda Passport?

It is the rear-drive Isuzu-pattern 4L30E kit, and Wikipedia lists both trucks with the 4L30E. Send us your VIN so we can confirm before it ships.

The listing says 1996-2019. Is there a 2019 vehicle with a 4L30E?

No. The 4L30E ended production in 2004. The range is the listing's; the kit is for the Isuzu, Honda and Acura SLX trucks that used the transmission.

Is the overdrive piston included?

No. This kit is listed without the overdrive piston. Steels, the band and the filter are also separate.

My 2000 Trooper has no reverse. Is it the clutches?

It can be, but on 2000-up Isuzu units a TCC solenoid stuck on can block reverse through the reverse block-out valve. Test the TCC solenoid and wiring before tearing it down.

What fluid goes in after the rebuild?

GM's 4L30E specification calls for Dexron III. Use the fluid named in your owner's manual if Isuzu, Honda or Acura lists a different one, and check the level hot.

• Transmission Slipping Diagnosis Guide
• Adaptive Relearn After a Valve Body or Rebuild
• How to Test a Transmission Solenoid with a Multimeter
• Transmission Overheating Causes and Prevention