4L30E 1997-1998 BMW 328i / 328is 2.8L RWD – Remanufactured 4-Speed Automatic Trans

Description

Developed for late-cycle compact luxury sedans, BMW 328i 1997-1998 Remanufactured Transmission supports the 2.8L engine with 190 continuous horsepower and 206 lb-ft maximum torque output. Operating beneath a 6,500 engine RPM ceiling, the unit commands 158 PSI line pressure, delivering crisp gear sequencing through this advanced 4-Speed 2WD drivetrain without hesitation.

High-pressure die-cast aluminum casing houses carburized 8620 steel helical gear sets alongside segmented carbon friction plates. Re-machined valve bodies receive precision-ground steel sleeves and oversized pressure regulator spools to prevent cross-leakage. Dual 3/8-inch inverted flare cooler fittings service a 160 lbs dry unit holding 8.8 quarts of fluid, integrating an internal overdrive section with a balanced lockup torque converter.

Key Features of BMW 328i

Independent repair shops buy BMW 328i 1997-1998 remanufactured transmission packages to restore factory shift response across high-demand fleet vehicles. This remanufactured package maintains dependable mechanical power transfer across demanding commercial routes.

• 4-Speed 2WD planetary gear units distribute power smoothly to rear drive axles under changing throttle load
• Heavy forward clutch packs prevent slip during hard highway passing acceleration
• 1997-1998 328i replacement valve body passages eliminate delayed gear engagement during cold mornings
• Hardened differential pinions survive continuous cyclic stress on rough city streets
• 328i 1997-1998 torque converter package features furnace-brazed turbine fins that stop flex
• High-output oil pump rotors maintain continuous fluid pressure across all clutch drums
• Viton lip seals eliminate internal hydraulic pressure bleed under elevated operating temperatures

Operating Pressure Dynamics Heat Thresholds

Controlled hydraulic circuit pressure ranges from 144 to 190 PSI during maximum throttle opening. Sump operating temperatures hover between 165°F to 195°F during continuous commuter operation. Rated for 206 lb-ft input torque at 3,950 RPM, gear ratios distribute through a 2.40:1 1st gear, 1.47:1 2nd gear, 1.00:1 3rd gear, and 0.72:1 overdrive. Radiator heat exchangers shed thermal surplus before fluid degradation begins.

Differential Output Register Subframe Positioning

The rear output utilizes a 3-bolt triangular drive flange connecting to factory driveshaft flex discs. Housing face to end pan distance measures 27.20 inches to fit factory engine bays. Chassis mounting pads align with original vibration dampers, keeping rear flange runout below 0.0018 inches to prevent floor vibration.

Computer Controlled Bench Dyno Screening

Computerized testing monitors solenoid response and clutch circuit pressure on a preheated dyno test rig simulating road grades. This driveline is not engineered for pro-mod drag racing, competition sled-pulling trucks running uncalibrated tuning, or drivelines with contaminated fluid coolers.

• Check transmission dipstick fluid clarity every 14 operating days
• Change fluid and install clean pan filters every 25,000 miles
• Inspect transmission harness connectors every 12 months

Fleet Protection Comprehensive Crate Packing

The transmission includes a 3-Year unlimited mileage warranty covering commercial use. The wooden shipping pallet contains one complete remanufactured transmission, an electronically tested torque converter, an external spin-on fluid filter, detailed installation instructions, and fluid specification documentation tags.