These are the two tools you will need to tighten and remove cylinder head pre-chamber Collar Nuts on 220D 240D 300D 300CD 300TD 300SD 300SDL 190D 2.2 1969 to 1987. Works on most Mercedes diesel engines up through 1987 only. ALSO FITS OM 636. Loose collar nuts are becoming epidemic on these old engines leading to air and fuel seepage around the base of the fuel injectors. They tend to loosen over time, especially when removing previously over-torqued fuel injectors! Free instructions included by watching the video below:
This important collar nut is torqued to between 100 and 120 foot-pounds to provide the proper seal between the pre-chamber and the cylinder head. There is no way one can put that amount of torque and a twin-notched nut like this without using some type of clamp to secure the socket to the nut. This prevents the socket from "jumping" out of the notches during tightening or loosening.
The threaded insert part of the tool is screwed down into the pre-chamber. With the notched socket seated tightly against the collar nut, a 32 mm socket and wrench is used to tighten or loosen the collar nut. In most cases just tightening the collar nut will solve most pre-chamber leak problems.
IMPORTANT REMINDER: This tool will only tighten and remove the collar nut. It WILL NOT remove the pre-chamber. If tightening the collar nut does not solve your leak problems, then you may have to remove the pre-chamber to install a new sealing ring under the top lip of the pre-chamber. The pre-chamber removal tool is available separately. Look below to order.