MH1 ✓ Factory-verified

Buick · Regular Production Option

Transmission, automatic, 4 speed, HMD, 4T80-E, electronic converter clutch

Years 1998–99, 2006–09 Models 2 Factory citations 4

Query this via API →

Also described as Transmission, automatic, 4 speed, THM 4T80-E, electronic converter clutch

Also documented for CadillacChevroletOldsmobilePontiac

Documented applications

Lucerne — G-body (2006–2011) →

• 2006–2009 ✓ Factory-verified
  ⛭ GM factory document — 2006 buick lucerne rpo code list, p.1.

  ⛭ GM factory document — 2009 buick lucerne rpo code list, p.1.

Riviera — G-body (1995–1999) →

• 1998–1999 ✓ Factory-verified

  the 4T80-E pairs with the 4.0L L47 V8, which the Riviera never had (Wikipedia shows only 3.8L V6 engines), so L47 is not listed; the code sits on both shared lists

  ⛭ GM factory document — 1998 buick riviera rpo code list, p.1.

  ⛭ GM factory document — 1999 buick riviera rpo code list, p.1.

This page aggregates every documented appearance of MH1 in the Buick reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.