8HP45 Master Rebuild Kit, new and ready to install. Fits the 8HP45. Ships fast from the USA.
If your BMW 328i, 528i, X3 or X5 with the ZF eight-speed has started flaring on the 2-3 or 3-4 shift, slipping when you pull out to pass, or leaving dark, burnt fluid on the drain plug magnet, the clutch packs inside the 8HP45 are the usual suspect once the electronics check out. This 8HP45 master rebuild kit is the friction overhaul set for that gearbox, the unit BMW stamps GA8HP45Z on the case tag. It is new, not a used pull, and it is meant for a bench rebuild where the transmission is out of the car and fully torn down.
The 8HP45 is the lighter-duty member of ZF's first-generation eight-speed family, sized for four-cylinder and six-cylinder engines rather than the big V8s that get the 8HP70 or 8HP90. Inside it, four simple planetary gear sets are controlled by five shift elements: two brakes, A and B, that hold members to the case, and three rotating clutches, C, D and E. Every gear uses three of those five elements applied at once, which is why one worn pack can spoil several gears instead of just one. The kit supplies the friction plates for those packs along with the gaskets and rubber sealing the overhaul needs, so each piston goes back in with fresh seals and each pack gets new lining. Check the product photo against your teardown for steel plates; reuse original steels only if they are flat, unscored and free of heat bluing.
Not every bad shift on an 8HP45 means the packs are worn. A low fluid level is the first thing BMW tells its technicians to rule out, and these units are easy to underfill because there is no dipstick. Valve body bore wear in the clutch holding and pressure regulator circuits can also produce flares and harsh shifts that mimic friction failure, and a worn or leaking mechatronic sleeve drops apply pressure the same way. Read the fault codes and adaptation values, check the level at the correct temperature, and pull the pan to look at what is on the magnet before committing to a teardown. Our ZF8HP common problems guide walks through those checks in order, and the ZF8HP rebuild cost breakdown explains when a reseal or valve body repair is enough and when the full overhaul is the better spend.
This kit is catalogued for the ZF 8HP45 in BMW 1 Series, 3 Series, 5 Series, X1, X3, X4 and X5 models, with Jaguar XF and XJ and Land Rover applications also listed. Treat that list as a starting point. BMW, Jaguar and Land Rover used several 8HP variants across those same nameplates, and some early model years in the list were still built with six-speed transmissions, so the only reliable check is the ZF tag on the side of the case. Make sure it reads 8HP45 or GA8HP45Z before you order. If you are unsure, send us your year and VIN and we will confirm it. You can see everything we carry for this family on the ZF 8HP parts page.
| Fits | 8HP45 |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is built for the ZF 8HP45, also stamped GA8HP45Z. BMW used the 8HP45 in many four- and six-cylinder 1, 3, 5 Series, X1, X3, X4 and X5 models, but the same nameplates also used other 8HP variants and some earlier years used a six-speed. Read the ZF tag on the transmission case or send us your year and VIN before ordering.
No. The 8HP50 is the second-generation replacement for the 8HP45 with different internals, and the 8HP70 is the larger first-generation unit used behind bigger engines. Order the kit that matches the exact code on your case tag.
Inspect and replace any worn bushings, thrust washers, the pump if it is scored, and any damaged drum or shell. If the original complaint involved solenoid or pressure faults, address the mechatronic as well, either with a solenoid set or a replacement valve body, so the new clutches are not cooked by bad apply pressure.
ZF LifeguardFluid 8 or an ATF that carries that approval. A dry, overhauled unit needs roughly 9 liters, and the level must be set at the fill plug at the correct fluid temperature with the engine running, since the transmission has no dipstick.
Yes. The transmission module learned clutch fill times on the worn packs. Clear the adaptations with a capable scan tool after the rebuild, then drive gently through all gears so it relearns on the new frictions.
Yes. Wear in the 8HP45 valve body clutch holding and pressure regulator bores can cause flares and harsh shifts that feel like slipping packs. Check codes, fluid level and the pan contents first so you do not rebuild a gearbox whose real fault is in the mechatronic.
