OM617 to GM manual transmission


Adapter kit contains-

  • Adapter plate
  • Custom flywheel
  • Crank pilot adapter
  • Hardware

Customer supplies-

  • GM clutch
  • GM pilot bushing or bearing
  • GM manual transmission
  • Ford V10 truck starter (’99 up truck, not van)


1. What is the cost of the kit?

$950 for the 4x4labs specific parts to adapt the OM617 engine to GM standard transmissions- engine adapter plate, custom flywheel, pilot bushing adapter and hardware.

2. What applications does this kit fit?

The vehicle choice will be up to you. We are developing motor mount kits, clutch slave cylinder brackets, throttle linkage adapters and a few other items for specific rigs but for now we are focusing on the adapters needed to mate the engine to the transmission.

3. What transmissions will work with this kit?

GM manuals are our first focus. SM420, SM465, NV3500, NV4500, NV5600 are in the first round. There may be other GM manuals that will work since our flywheel will have bolt patterns for both the GM 11 and 12 inch clutches.

4. What does the kit come with?

The basic adapter kit will include the 4x4labs specific adapters- engine adapter plate, a custom flywheel and pilot bushing adapter. You will be responsible for off the shelf parts (GM clutch, GM pilot bushing or bearing, starter etc)

5. What are the TQ and HP #’s for the om617?

Power specs vary from year to year. The range is from 79hp – 125lb/ft for the non-turbo to 135hp 181lb/ft for the later turbo engines. If you do some web research there is a bit of variance in these numbers. There are reports of 170hp and 200lb/ft easily attained by adjusting fuel and turbo pressure. We have an engine dyno available and will be experimenting with this in the near future.

6. Will my fuel tank and lines work?

Fuel lines and tank will work with diesel, drain the gas out and fill it with diesel. One concern is the fuel return line that is necessary for the diesel. In most cases your vehicle will have this provision although it is usually called a vapor recovery line for gasoline engines.

7. What electrical work will have to be done?

There are very few electrical connections needed for this engine to run.
The main device is the glow plug timer/relay system which consists of pre-glow time relay, temperature sensor and indicator lamp. This equipment is housed in a small black box usually on the driver fender of the donor vehicle. There are 6 wires, 3 of which are essential. Other than the pre-glow system the alternator and gauges are the only other electrical components.

8. What year MB should I look for?

The OM617 came in 1978-1985 300 cars.

9. What has to be done to balance the flywheel to the engine?

When replacing the flywheel, the balance of the engine should be maintained as much as possible. The new flywheel should be brought to the same balancing condition as the old flywheel. A simple 180 degree balancing operation is performed. We offer this service. You can send us your flywheel and we will send you the new flywheel balanced to the same specs as the old one. You must mark the flywheel before removing it so that the same balance point is retained when installing the new unit.

10. Can 4×4 Labs perform the full conversion upon request?
Roughly how much would that cost?

Full turnkey engine conversions can run anywhere from $10-$25k at this shop.
You can make an appointment to go over your requirements. We will look at the vehicle and talk to you about your needs and wants and then we can give you an estimate of the cost.

11. Are other major drive train modifications required?

Depending on your vehicle you may need to change the length of the drive shafts or change the location of the transmission and transfer case.

12. Any top or bottom clearance issues?

Rough dimensions are- Length 33.5″ back of valve cover to front of fan, Depth 27″ top of valve cover to bottom of oil pan, Width 14.5″ widest part of oil pan. The OM617 has a front sump oil pan so there may be some differential interference on spring under 4wd rigs.

13. Can the stock Toyota gauges be reused with the OM617 setup?

The stock gauges can be used by either modifying the orifice in the head or engine block to accept the stock sender or by installing an electrical device inline to make the resistance in the sender and gauge compatible.

14. Are other systems compatible (power steering, power brakes, a/c, etc)?

Brakes are assisted by vacuum. The stock Mercedes vacuum pump is more than sufficient to activate the brakes in most vehicles. The Vickers power steering pump found on the OM617 engine is a powerful unit and works well with Saginaw power steering boxes.

15. What about other transmissions?

We are working on developing a line of adapters for this engine. We will continue development of these adapters because we believe this engine is one of the best automotive power plants ever produced. Our development time line is uncertain at this point but we have overwhelming interest in these adapters. Our production decisions are largely based on feedback we get from you and we have a list of transmissions we will develop for.

Toyota pickup- G52, G54, W56, R150 – Available now

Toyota Landcruiser- H41, H42, H55F, A440F

Jeep- AX-15