Project: Benchjob Transaxle Rebuild - 1991 Porsche 911 AWD (All Wheel Drive)
(Transaxle = Transmission and Differential - combined unit)
ZF 4HP22-HL (“HL” is for rear-end engines)
The 4HP22 is a 4-speed automatic transmission for passenger cars from ZF Friedrichshafen AG. Introduced in 1980, it was produced through 2003 and has been used in a variety of cars from BMW, Jaguar, Porsche, Land Rover, Maserati, Peugeot, and Volvo. For Porsche, it was used in the “HL” transaxle version from 1989 to 1993 in the Porsche 911 Carrera II 3.6L model.
Customer: Kent Danucci, Nebraska
VIN: WP0CB2967MS461877, 1991 Porsche 911 Carrera, red in color, 96,108 miles
Repair Order #: 15.040 / Woodhouse Porsche Omaha 402-592-1000 RO # 8041484
First Contact: 20 SEP 2007
Transmission arrived from Porsche Dealership on-site at Freddie’s: 17 OCT 2007
Rebuild completed and shipped back to Porsche Dealership in Nebraska: 08 NOV 2007
Below 236 pictures: dismantle & inspection, the cleaning and rebuilding process, and
attaching torque converter, packing, and shipping
Cleaning & Rebuilding the Transaxle
(Transmission & Differential combined unit)
Includes various upgrades, such as “A” Clutch Modification from 5 clutches (shown just above, marked as ‘main cause for reported problem’) to 6 to avoid early distress wear, updated forward piston, and others.

We were waiting for the outer O-ring and the inner seal for this part from the Porsche Wholesale Parts Supply to finish the rebuild.
Both arrived today, 05 NOV 2007.
Two (2) Data CD’s with the picture documention shown here
were sent to the owner of the vehicle.
This concludes the rebuild process ;-)
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