Volvo 240 8HP Swap
After the M47 gearbox finally gave up, we found ourselves revisiting transmission options for the Volvo 240. While stronger manual alternatives remain on the table for future projects, an opportunity arose to explore something different. The car’s existing Haltech Nexus R3 setup made it an ideal platform to collaborate with High Performance Academy and demonstrate the integration between a standalone ECU and an aftermarket transmission controller, in this case the TurboLamik TCU controlling the ZF 8HP.
Beyond simply solving our transmission problem, the project presented an opportunity to challenge ourselves with a platform we had not previously worked with. We’ve always been drawn to projects that push us to learn something new, and whenever there is an opportunity to work alongside others, the process is usually more rewarding. For a car that spends most of its life on the street, the 8HP quickly began to make a lot of sense.
Selecting a TCU
Now in 2026, there are several options available for controlling the ZF 8HP platform. From our research, options include integrated ECU solutions such as MaxxECU, CAN-based systems like CANTCU that retain and manipulate the OEM BMW mechatronics, and dedicated transmission controllers such as TurboLamik. Since our Volvo was already operating on a Haltech Nexus R3 that we were happy with, we chose the TurboLamik route.
Its sole purpose is transmission control, and from our perspective, it currently offers some of the most configurable and user-definable setup options available. That flexibility comes with additional setup and tuning complexity, but also the potential to tailor the transmission to the application. Setting up and tuning the TCU in conjunction with the ECU is the most important step however the focus of this article is the physical installation of the 8HP into the Volvo 240 and, by sharing our experience, hopefully we can simplify the process for others considering the swap.
Check out HPA for the in-depth tuning detail, they are widely regarded as the gold standard for learning this stuff. Unless you have a local tuner experienced with TurboLamik, we suggest learning the platform yourself.
At the time of writing this blog, HPA have released both a webinar featuring this car and a dedicated transmission tuning course covering the fundamentals needed to get a project like this moving. 8hp worked examples are coming soon.
Because this project was completed in collaboration with HPA, we can also pass on a couple of discount codes to help if you decide to dive deeper.
ANDO500 – $500 off HPA VIP Package
ANDO55 – 55% off any HPA course or starter package
In the context of a conversion like this, the investment in knowledge can quickly save both time and tuning costs. At current pricing, the transmission tuning course is honestly an absolute steal compared with the overall cost of an 8HP swap, it's much cheaper than paying someone else to do it for you, especially if you want them to spend the extra time to get it right.
Selecting a Transmission
The first piece of the puzzle is the gearbox itself. While commonly grouped together as “8HP” transmissions, the ZF 8-speed family includes several different variants with varying case sizes, bellhousings and torque capacities. In simple terms, the 8HP45/50/55 family represents the smaller transmission case, while the 8HP70/75/90 gearboxes are physically larger and intended for higher torque applications. Given the relatively tight transmission tunnel of the Volvo 240, packaging was a major consideration. Despite our engine producing around 500Nm at the wheels, the reputation of the 8HP platform for handling significant torque made the smaller case transmission a realistic option. For this build, we selected an 8HP50 sourced from a rear wheel drive BMW B58-powered 340i, offering a balance of compact size, updates/revisions compared to the earlier 8HP45 and proven torque capacity
Adapter Kit
Making the conversion work starts with an adapter between the Volvo Redblock and the 8HP. At the time of writing, DomiWorks has established itself as one of the benchmark solutions for 8HP conversions, producing exceptionally well-made components with strong roots in the Volvo community. Their adapter system has evolved to fit the many variations of the 8HP family and supports both factory engine slant and upright configurations. In our case, the engine remains on its original slant mounts. One point worth mentioning is that the DomiWorks adapter kit does not currently include installation instructions, so expect some logical problem solving and trial fitting during assembly. The components themselves are exceptionally well made, however much of the installation is worked out as you go.
You will also require a B230 automatic flexplate for this conversion. Since our car began life as a manual, this was not something we already had available. Luckily we had access to another B230 fitted with an automatic transmission and were able to source one from there.
Installation
While the DomiWorks kit provides an excellent foundation, there are still several modifications required to physically package the 8HP into a Volvo 240. The following photos cover the process, beginning with gearbox trimming to remove unnecessary tabs and casting features for tunnel clearance.
followed by starter motor clearance on both the adaptor and the bellhousing
If you intend to retain the factory flywheel-mounted crank sensor, additional clearance is also required at the top of the bellhousing, In our case this was unnecessary, as the engine runs a Yoshifab cam angle sensor on the auxiliary shaft.
The lower sump cradle must remain removed during transmission installation to allow access to the torque converter bolts, however once the gearbox is in place, access to several adapter-to-cradle fasteners becomes restricted. To solve this, the lower bellhousing requires several relief cuts to maintain assembly access.
None of these modifications are particularly difficult, but understanding them ahead of time can save a considerable amount of repeated assembly and unnecessary rework.
TurboLamik Control Installation
Before installation into the car, the TurboLamik controller requires its dedicated control board to be installed within the transmission itself. Since this involves opening the transmission and accessing the valve body, we found it far easier to complete this work on the bench before fitting the gearbox to the vehicle.
The process begins by removing the transmission oil pan and disassembling the valve body, allowing the factory card to be removed and replaced with the TurboLamik control card. While not particularly difficult, this stage does involve some delicate assembly and soldered connections.
Once installed, we chose to encapsulate the board using an electronics-grade potting compound to eliminate any possibility of vibration affecting the solder joints or causing reliability issues over time. From there, the transmission is reassembled following the factory configuration.
Tunnel Clearance
Fortunately, the 8HP50 fits surprisingly well within the Volvo 240 transmission tunnel and requires very little chassis modification. In our case, only a single interference point required attention, located at the centre of the firewall where it transitions into the tunnel, directly behind the factory crank sensor position. Due to the thickness of the adapter plate, the bellhousing sits slightly further rearward and makes contact in this area. The challenge is not the amount of clearance required, but the access. With the engine in place, swinging a hammer in this location is difficult, and that Swedish Volvo metal is no joke. We ultimately used a pneumatic air hammer with a modified tool to create the necessary clearance. The good news is that this is the only chassis modification required, and once addressed, the gearbox sits very comfortably within the tunnel.
A small installation trick we found helpful was to lightly jack the front of the engine using a block of wood. Tilting the engine rearward slightly improves access to the bellhousing bolts and makes it much easier to install before lifting the rear of the transmission into its final position.
Important Notes
One detail worth checking during installation relates to torque converter float. Before final tightening of the torque converter hardware and installation of the lower sump brace, confirm that the torque converter still has a small amount of free movement by hand. This clearance is important, allowing for correct seating and thermal growth during operation. From our research, incorrect converter clearance has proven to be a stumbling point for other 8HP conversions and is worth confirming before moving forward.
It is also worth confirming starter engagement during initial assembly. Before finalising the installation and tightening everything permanently, check that the starter fully engages the flexplate correctly. In our case, starter clearance required attention at both the adapter plate and bellhousing, and confirming proper engagement early can save significant rework later. Making sure the starter is fully seated before proceeding is a simple step that can prevent unnecessary disassembly.
Gearbox Crossmember
With the transmission physically fitting the tunnel, the next task was supporting it correctly. Before removing the M47, we measured the original output shaft centreline to ensure the new transmission would sit in the same position and avoid introducing unwanted driveline angles or vibration issues. From there, we measured the factory mounting locations and modelled a new crossmember in CAD using little more than a ruler and some careful measuring.
Since the 8HP is considerably longer than the M47 due to the additional gear sets, the mounting position moves further rearward in the chassis. The 8HP is also noticeably heavier than the M47, out of interest we weighed it. Stock m47 full of oil was 39.5kg, and the 8hp before adding 7.5l of oil was 74.5kg so we intentionally overbuilt our crossmember. Ours was laser cut from 4mm stainless steel and TIG welded together using the factory BMW rubber transmission mounts. Stainless was not strictly necessary, but it suited the tooling and fabrication process we had available.
One detail we discovered during installation was that the Volvo floor shape is not perfectly symmetrical. Although the factory mounting points are consistent, the left-hand side floor depth sits slightly lower inboard of the mounts. This required a small amount of trimming to our fabricated crossmember during final fitment, a good reminder that custom fabrication rarely fits perfectly the first time. Once adjusted, the transmission sat correctly with the output shaft positioned to match the original driveline geometry.
Driveshaft
With the gearbox output flange now positioned further rearward in the chassis, the driveshaft also required modification. Purchasing the BMW donor transmission with its original driveshaft simplified the process considerably.
BMW also use a rubber guibo and a center bearing so this was relatively straight forward. We retained the Volvo driveshaft and adapted the BMW front flange to suit the 8HP output and BMW rubber guibo arrangement. (BMW have a spigot that locates in the Guibo this is important to retain) The driveshaft was carefully measured, shortened by 130mm and professionally balanced by a driveshaft specialist. Importantly, this dimension also maintained the correct engagement within the Volvo slip joint.
The end result is largely a Volvo driveshaft with BMW hardware at the front, allowing us to retain the rubber damping while maintaining correct driveline alignment and factory-style flexibility.
Transmission Cooling
The final piece of the physical installation was transmission cooling. For this setup, we used a Setrab oil cooler mounted ahead of the radiator, identical to the engine oil cooler already used on the car. From there, Speedflow 200 series hose was routed back to the transmission using DomiWorks AN adaptor fittings, which provide a simple solution for connecting to the 8HP cooler ports.
As this was our first experience with the 8HP platform, we deliberately kept the cooling system simple and chose not to install a thermostatic bypass initially. We selected a reasonably sized cooler and decided to monitor transmission temperatures in real-world use before committing to additional hardware. If we were aiming for a more comprehensive solution from day one, an AN-style thermostat block such as those offered by Hell Performance appears to be a very tidy option. However, this introduces additional cost and complexity through both the thermostat itself and the extra AN fittings required.
For now, we have chosen to keep things simple, gather real data and make decisions based on how the car performs.
With cooling in place, the physical installation of the gearbox was complete.
Transmission Fluid Filling
The final step before putting the car into service was filling the transmission. Since the TurboLamik control board installation requires removal of the oil pan and valve body, much of the transmission fluid is drained during the process.
Filling the 8HP is a two-stage process. The transmission is initially filled cold until fluid reaches the overflow point. Once the engine is running, the transmission begins circulating oil through the valve body, torque converter and cooling circuit, requiring a second filling stage with the gearbox operating. We repeated this process while allowing the transmission to heat cycle and reach the appropriate temperature for final level adjustment.
In our case, the transmission accepted a total of 7.5 litres of fluid. Given that the torque converter remained installed and some residual oil stayed within the system, this aligned with expectations for our setup. Overall capacity of the 8HP50 is generally around the 9-litre mark, depending on variant.
Since this gearbox had travelled only around 25,000km, we chose not to perform a full service or filter replacement at this stage.
Exhaust
In our case, the additional size of the 8HP within the transmission tunnel meant the original exhaust no longer fit alongside the gearbox. We remade the mid-section of the exhaust to suit. Depending on your existing system and tunnel clearance, expect that some level of exhaust modification.
Electronics
The final piece of the puzzle is the shifter assembly and TurboLamik control unit. At the time of writing this blog, High Performance Academy has already released an excellent webinar covering the TurboLamik software, initial setup, covering some lessons learned during installation.
From a wiring perspective, the TurboLamik is relatively straightforward, though CAN communication between the ECU and controller requires attention depending on your ECU platform. One detail we discovered with the Haltech system relates to shift requests, where Haltech CAN alone was slightly too slow. Our solution was to use dedicated digital outputs between the TurboLamik and Haltech, allowing these critical signals to transmit immediately.
Much of the software setup and tuning process is best learned through dedicated training. While we’re not here to push courses, HPA offer a transmission tuning course covering 8HP setups in detail. In a conversion like this, the investment in knowledge can quickly save both time and tuning costs.
Interior Package
With the driveline and electronics sorted, attention turned to the interior package. For this build we chose the DCT shifter and clutch emulator, allowing the car to retain a manual-style driving experience while running the 8HP transmission. Turbolamik has sports modes and manual modes as programmable options.
The clutch emulator is a clever solution. Rather than physically actuating anything within the driveline, it simulates clutch resistance and pedal feel through an internal hydraulic system and pressure sensor. This makes installation straightforward. We retained the clutch master cylinder, routed a hydraulic line to the emulator and mounted the unit beneath the dash without needing to convert to an automatic pedal box. Pedal engagement points are adjustable in the software, creating a convincing clutch-like feel while keeping the installation simple however we did need to change the supplied pressure sensor for a range that worked in the software.
The DCT shifter itself is a standout piece of hardware. Whether left in automatic mode or shifted manually, it adds another layer of involvement and makes the car genuinely rewarding to drive.
We routed the TurboLamik loom through the factory shifter opening, folding the tunnel lip slightly to protect the harness. From there, we designed and 3D printed a shifter pedestal mount using the original floor mounting points, incorporating the LCD display and program dial into a single assembly.
Our first prototype did not survive long and quickly highlighted the limitations of coarse printed plastics in this application. A revised version is performing well for now, although an aluminium printed or fabricated mount would likely be the ideal long-term solution for maximum durability.
Additional Notes & Observations
A final observation relates to vibration and NVH. Our car already used poly engine mounts, which introduced a small amount of vibration even before the conversion. With the added mass of the 8HP, this became considerably more noticeable and, for a street-driven car, verged on excessive. The gearbox itself runs on factory BMW rubber transmission mounts, which performed well, the engine mounting arrangement is likely where further refinement is required. For the moment, we will likely return to rubber engine mounts while exploring improved mounting arm designs capable of using a stronger and more suitable isolator than the factory Volvo arrangement. At this stage, increased NVH is probably the biggest drawback of the swap and is worth considering if your vehicle already runs stiff or solid mounts.
How long does the swap take.
In our case 3 full working days with 3 Professionals to the point of test driving down the street on a Turbolamik base map not including any tuning.
Our team was made up of 2 race mechanics and 1 wiring expert. We also had a full race shop of tools on hand. however we probably installed this gearbox 8 times while we learnt all the little clearance issues so hopefully this Blog saves you guys at least a days work and helps with planning.
This swap is 100% possible on your home garage floor with basic tools, but it will take longer than a weekend. Good luck
