ZF 4HP Series 4-Speed Automatic Transmission (BMW) · BMW / MINI · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
1982–1995 BMW 5 Series (E28/E34), 1982–1992 BMW 6 Series (E24), 1988–1994 BMW 7 Series (E32), 1989–1995 BMW 3 Series (E30/E36 V6)
| Configuration | 4-speed automatic RWD transmission |
|---|---|
| Gear Ratios | 1st 2.48:1 · 2nd 1.48:1 · 3rd 1.00:1 · 4th 0.73:1 · Rev 2.09:1 |
| Fluid Type | Dexron II/III or BMW ATF |
| Fluid Capacity | 6.5 qts total, 3.0 qts service refill |
The centrifugal governor valve wears, causing erratic or stuck shift points. Common on E28/E34 units over 150,000 miles.
Symptoms: High-RPM shifts, transmission staying in low gear, erratic shift timing at varying speeds
Accumulator piston seals harden with age, causing harsh shift engagement as hydraulic cushioning is lost.
Symptoms: Harsh, clunking shifts especially on cold startup, shift shock when accelerating
The torque converter pump and stator wear on high-mileage units, causing efficiency loss and engagement slip.
Symptoms: Sluggish acceleration from stop, transmission slipping at cruise, fuel economy drop
ZF 4HP rebuild replaces governor valve assembly, all accumulator piston seals, clutch packs, and all seals. Torque converter is rebuilt or exchanged. All bearings renewed.
Dexron III or approved BMW ATF every 40,000 miles. These are classic BMW transmissions — proper fluid maintenance extends service life dramatically on well-maintained E28 and E34 BMWs.
E28/E34 5 Series, E24 6 Series, E32 7 Series, and some E30/E36 3 Series models from 1982–1995.
Yes — it's a robust, well-designed 4-speed. Most failures are age-related wear, not design defects.
A full rebuild ranges $1,600–$2,100 at Chicago Transmission.
Dexron II/III or BMW-approved ATF. These are older units that use commonly available ATF.
Absolutely — we regularly rebuild these for BMW classic car restorations.
Free diagnostic, written estimate, lifetime warranty. Chicago's ZF 4HP18/22/24 rebuild specialists since 1987.
