Seals, gaskets, o-rings and friction clutch plates to overhaul the ZF 6HP26 in BMW X5, 550i, 750i, Jaguar and Land Rover.
Rebuilding the 6HP26 out of an E60 550i, an E65 or E66 750i, an E70 X5 or a Jaguar or Land Rover V8 means taking every drum apart, and once you are that deep there is no reason to reuse a single seal. This kit is the soft-parts package for that job: pan gasket, case and pump O-rings, piston lip seals, shaft sealing rings, the small rubber pieces that tear on teardown, and a full set of new friction clutch plates. It is listed under ZF overhaul reference 1068298051 and sold in the trade as T18302A, weighing in at about 14.4 lb.
Inside the 6HP26 there are five shift elements: the A, B and E clutches drive parts of the gear train, and the C and D brakes hold them to the case. Each is applied by a hydraulic piston, and the rotating clutches are fed through sealing rings on their shafts. The converter clutch is run with a controlled slip much of the time, which puts steady heat into the fluid, and over high mileage that heat glazes the friction lining and takes the stretch out of the rubber. The result is a unit that still drives but shifts slower and slips under load because apply pressure leaks past the seals before it reaches the clutch. Fitting new frictions on old seals, or new seals on glazed frictions, just moves the problem. This kit does both.
On a BMW, check the transmission connector first. Oil wicking through a worn sealing sleeve causes intermittent communication faults and limp mode that are easy to mistake for an internal failure, and the fix is a seal, not a rebuild. Then set the fluid level properly and drive it again. If it still slips, pull the pan: a pan full of friction material means the clutches are finished. Our BMW 5 Series 6HP shift problems guide lays out the order of checks, and converter shudder is covered in the 5 Series common problems guide.
The kit is listed for the 6HP26, 6HP26A and 6HP28 rear-wheel and all-wheel drive units, roughly 2002 through 2011: BMW E60 550i, E65/E66 750i, E70 X5 and E71 X6, Jaguar S-Type, XJ and XK, and Land Rover Discovery 3 and Range Rover Sport. The smaller 6HP19 and 6HP21 use a different clutch stack, and Sonnax notes the 6HP26 is a Generation 1 design while the 6HP28 is Generation 2, so read the ZF identification tag on the case before you order. If the tag is gone or painted over, send us the year and VIN. You will find frictions, seal kits, solenoids and valve bodies for the whole family on our ZF 6HP collection page.
Weighing a rebuild against a replacement unit? Read the ZF6HP rebuild cost guide first.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the 6HP26 family, which includes the E70 X5 and E71 X6 with the six-speed automatic, along with the E60 550i and E65/E66 750i. Smaller-engine BMWs often use the 6HP19 or 6HP21, which take a different kit, so check the ZF tag or send us your VIN.
No filter is included; on the 6HP26 the filter is part of the plastic pan, which is sold separately. The listing describes friction plates plus the full seal and gasket set, so inspect your steels and replace any that are blued, scored or warped.
Hardened lip seals and worn sealing rings leak more once the fluid thins out at operating temperature, so apply pressure drops and the clutches slip. Low fluid level does the same thing, so set the level correctly before deciding on a rebuild.
ZF LifeguardFluid 6. After a rebuild, fill through the fill plug until it runs out, cycle the gears at idle, then set the final level with the oil warm. A dry unit takes considerably more than a pan service.
No. The connector sealing sleeve and adapter seals are a separate kit. Replace them during the rebuild if the old unit showed any oil at the plug.
