Nearly every question we get about the ZF 8HP starts the same way: someone found a transmission on a marketplace listing, the seller says it is "an 8-speed out of a BMW," and the buyer wants to know whether our conversion kit will bolt to it.
We cannot answer that until we know four things — the family number, the OEM it came from, whether it is rear-drive or all-wheel-drive, and what generation it is. Those four data points decide bellhousing pattern, converter pilot, output flange, wiring, and whether a standalone controller can talk to it at all.
What the numbers actually mean
ZF's naming convention is simple once you see it broken apart.
Applied across the range, that gives you a straightforward capacity ladder:
The rating describes input torque at the converter, not crank torque and definitely not horsepower. A high-boost 2JZ that makes its torque in a narrow band loads a transmission very differently from a diesel making peak torque just off idle.
Where BMW's naming fits
BMW labels these GA8HP45Z, GA8HP50Z, GA8HP70Z, GA8HP75Z and GA8HP90Z. The GA prefix and Z suffix are BMW's internal codes for transmission type and supplier. The middle section is still the ZF family number, so a GA8HP70Z is an 8HP70.
Where Mopar's naming does not
This is the single biggest source of confusion for our Dodge and Jeep customers. Stellantis builds a licensed version in Kokomo, Indiana, under a different name:
| Mopar name | ZF equivalent | What "RE" means |
|---|---|---|
| 845RE | 8HP45 | Rear-drive, Electronic — Stellantis nomenclature, not ZF's |
| 850RE | 8HP50 | |
| 875RE | 8HP75 | |
| 8HP70 / 8HP90 / 8HP95 | Same | Units carrying the ZF name in Mopar vehicles are generally ZF-supplied rather than Kokomo-built |
Family match is not fitment match. An 845RE and an 8HP45 share a family, but they came out of different vehicles with different bellhousings, converters and control software.
The four checks that determine fitment
1. Which OEM bellhousing is on it?
The bellhousing is cast as part of the main case on the 8HP. It is not a bolt-on component you can swap between brands. A BMW 8HP70 and a Dodge 8HP70 are the same family and will not accept each other's adapter hardware, because the case itself is different where it meets the engine.
2. Rear-wheel drive or all-wheel drive?
All-wheel-drive variants — BMW xDrive, Audi's quattro-spec A-suffix units, Jeep and Ram 4WD — carry a transfer case output and a different rear case. They are frequently cheaper on the used market for exactly that reason, and that price gap catches people out.
3. Generation 1, 2 or 3?
ZF has revised the 8HP substantially across three generations, roughly 2009, 2014 and 2022 onward. Generations differ in mechatronic hardware, internal hydraulic circuits and communication behaviour. A controller configuration that works cleanly on one generation is not guaranteed to work on the next.
4. What is the plan for control?
The factory TCU is calibrated for the vehicle it shipped in. Drop a Jaguar-sourced transmission behind a Honda K24 and nothing meaningful happens on the CAN bus. Swaps need a standalone controller — we stock the TurboLamik TCU 8HP Controller, and we compare the options in our 8HP70 controller comparison.
ASE 8HP conversion kit coverage
Everything below is designed and CNC machined in Lakeland, Florida.
| Engine | Donor transmission | ASE kit | SKU |
|---|---|---|---|
| 2JZ / 1JZ | BMW 8HP50 / 51 / 70 / 75 | JZ to BMW 8HP kit | 81001 |
| 2JZ / 1JZ | Dodge Ram truck 8HP70 / 75 / 90 / 95 | JZ to Dodge Ram 8HP kit | 81003 |
| 2JZ / 1JZ | Dodge Mopar car 8HP50 / 70 / 75 / 90 / 95 | JZ to Dodge Mopar 8HP kit | 81004 |
| 2JZ / 1JZ | Jaguar 8HP45 / 70 | JZ to Jaguar 8HP kit | 81005 |
| 2JZ / 1JZ | Dodge / Jeep EcoDiesel 8HP | JZ to EcoDiesel 8HP kit | 81007 |
| 2JZ / 1JZ | BMW N63 8HP70 | JZ to BMW N63 8HP70 kit | 81008 |
| K20 / K24 | BMW 8HP50 / 51 / 70 / 75 | K-series to BMW 8HP kit | 81002 |
| K20 / K24 | Dodge 8HP70 / 90 | K-series to Dodge 8HP kit | 81009 |
| K20 / K24 | Jaguar 8HP45 / 70 | K-series to Jaguar 8HP kit | 81010 |
| Nissan SR20 | Dodge Ram 8HP70 / 75 / 90 / 95 | SR20 to Dodge Ram 8HP kit | 81006 |
| LS / LT | Dodge Mopar 8HP70 / 75 / 90 / 95 | LS/LT to Mopar 8HP kit | 81011 |
| BMW N52 / N53 / N54 / N55 | Dodge 8HP70 / 90 | BMW N-series to Dodge 8HP kit | 14260 |
Which family should you buy?
| Build type | Target output | Family | Why |
|---|---|---|---|
| Street / light track | Under ~450 lb-ft | 8HP50 | Usually the cheapest sensible core. The 8HP45 works but has less margin, and margin is the point of buying used. |
| Drift / turbo swap | ~450–650 lb-ft | 8HP70 or 8HP75 | Deepest aftermarket: cores, adapters, flanges, pans and controller calibrations are all easiest to source here. |
| Drag / heavy V8 | Above ~650 lb-ft | 8HP90 or 8HP95 | Extra clutch capacity is not marketing. Transbrake launches are a different loading case entirely. |
Buying one family down and planning to "just keep the tune conservative" tends not to survive contact with the first event.
Before you buy the core
Family number and OEM are only half the picture. Nameplate verification, selector type, flood history and adapter availability all decide whether a cheap core turns into a cheap build. We cover that in our companion guide, Buying a Used ZF 8HP.
Once you know what you have, the next question is usually gearing — and the ratio set inside an 8HP does not follow the family number either. That is covered in ZF 8HP gear ratios by generation.
If you already know what transmission you have and want fitment confirmed before you spend money, send us the nameplate photo and the engine you are running. We would rather answer that email than process a return.