(Return to General Isuzu Information.)
1984-85 - 4-Speed manual
1986-87 - MSG-5 5-speed manual
1988-2004 - MUA-5 5-speed manual
1988-1991 - Aisin-Warner A340H 4 speed automatic for 4 cyl 2.6L Isuzu engine, GM 4L30-E 4 speed automatic for 2.8L V6 GM engine
1992-2003 - GM 4L30-E 4 speed automatic for Isuzu 3.2 V6
2004 - DI models had Aisin automatic
History of the 4L30-E Transmission
It all starts back in the 60’s and early 70’s. Opel, the European car manufacturer starts selling their Kadett, Rekord and other models with the then popular “Trimatic” and later called “TH180” automatic transmissions.
After adding a converter clutch this trans became known as the “TH180-C”. In the USA the “TH180-C” got it’s fame under the name 3L30. Throughout this period all GM transmissions were and still are produced at the General Motors plant in Strasbourg, France. As both Opel and Buick were part of the General Motors group, Opel reached the US market through the Buick dealerships.
For reasons only GM knows they decided to add an overdrive to the 3L30. As the main case of the 3L30 could not accommodate the overdrive they were forced to put it in it’s own case and mounted it in front of the 3L30. The 4L30-E was born ! This adaptor case has it’s own valve body and even it’s own oil pan.
The 4L30-E became so popular that other car manufacturers started using it. You can find this transmission in Isuzu SUVs, BMW’s 3 and 5 series and probably a few more brands.
The 4L30-E designation system is as follows:
4 = Four speed, L = Longitudinal, 30 = Series based on torque capacity, E = Electronic controlled.
Note: All 4L30E and MUA-5 manuals had gear driven transfer cases, while the A340H had a chain driven transfer case.
Note on 92 and up transmissions.: Automatics since 1992 have been the GM 4L30E, unless you buy a 2004 with the Direct Injected 3.5L (DI only in Rodeos and Axioms). DI vehicles had an Aisin automatic. All 92 and up manual transmissions are the Isuzu MUA-5, except for 2.6L Rodeo's, which have a Borg Warner 5 speed (2wd).
Note on 4L30-E interchangeability: All 4L30-E transmissions used between 1992 to the middle of 1999 are interchangeable between vehicles manufactured in those same years. In 1999, there were some changes to the 4L30-E electronics that require vehicles from mid-1999 and up to use a newer 4L30-E from the same range of years.