Don't let this happen to your S55 M2 M3 M4
Tools needed:
- 2-post automotive lift
- ¾ inch breaker bar and socket for crank bolt (S55 breakaway torque for crank bolt is over 440 ft/lbs torque!)
- Torque wrench capable of OEM crank bolt torque
- Crank locking tool
- BMW Timing tools
- Crank seal/front seal install tools
- Engine support cradle
- Small 3/8" drill
- Tap Magic or other heavy oil for drilling
You will also need the following OEM parts to complete the job at the minimum:
- Valve cover gasket set
- Front crank seal
- (2) Front cover seals
- (2) Vanos bolts
- Oil pan bolts
- Oil pan gasket
- BMW Coolant
- Engine oil
The install process requires you to follow the factory disassembly process until the timing gear, oil pump gear, and crank hub are removed. You will also need to remove the oil pan prior to drilling the snout of the crank. We recommend taking the valve cover off before suspending the engine to drop the front subframe and oil pan.
The vanos components, timing chain and cassette is fully removed, or at least lifted out of the way. The oil pump chain and cassette can remain installed, with the chain tucked out of the way. Remove the crank seal for access to installing the drill fixture and shortened bolt. Use caution to not damage the area where the crank seal sits. The rotation/position of the two holes that you will be drilling is not critical, however it is important that the fixture does not move once you have drilled any of the holes.
**** Please check proper fitment of the drill fixture in the end of the crankshaft. S55 fitment has been very snug. There has been a N54 that had some minimal play which can result in the dowel holes not getting drilled on-center. This can be shimmed using layers of foil wrapped around the drill template as needed. If there are any concerns please contact us prior to drilling ****
**** You need to make sure the holes are deep enough to have the dowel pins fit in the crank snout without bottoming out **** We suggest measuring the exposed length of the dowel pins (should be close to .120"). Insert the drill bit inside the install tool so that it protrudes slightly further than the dowel length, putting some tape or a sharpie mark on the drill bit to provide a suggested stop point. Do this prior to installing the drill fixture on the crankshaft.
Tighten the drill fixture with the supplied short bolt to the crank snout. The drill bit supplied is a carbide straight flute bit. It is very hard, and also fairly brittle. It requires good lubrication, slow to moderate speed, and mild pressure. If you side load it, it will snap. Take your time, use lots of lube, and it should go smoothly. We suggest using tap magic, gear oil, or motor oil. In the case of failure, the bits are readily available at Mcmaster Carr. The good news is they typically just fracture and can be removed with a small pick.
Once four holes are drilled, carefully brake clean/blow out the holes with the drill fixture still installed. This can be done while holding a shop vac in the vicinity of the chips. Try not to blow any chips upwards as you do not want to get debris in the assembled top end of the motor. Make sure you wipe any chips or debris that could accumulate at the inside of the front of the motor on the passenger side. There is an inner lip that could accumulate debris. Wipe that portion with a rag and check with your finger for debris. If it is good, you are ready to reinstall per factory install process.
Tightening procedure: We recommend cleaning the inside threads of the crank and the crank bolt itself, and applying oil to the threads and bottom of the bolt head prior to assembly. We hold the crank hub with a tool from the front of the motor while tightening the crank bolt instead of holding the crank with a flywheel locking tool. This eliminates the possibility of damaging the dowel pins during the torque procedure, and it stops you from twisting the entire crank during the install process. We still pin the flywheel with the locking tool at the same time.
S55 and N55 bolt torque - 100Nm initial torque plus 270 degrees.
N54 Bolt torque - 100Nm initial torque plus 360 degrees.
This page serves as a guide to aide in the installation of the crank hub. MODE Auto Concepts or SSR Performance accepts no liability in the incorrect use or improper installation of the crank hub or use of these instructions. Please only have a skilled workshop / technician install this product. There is no margin for error during this complex install.
