Foreward:
I was lucky enough to find myself with the dreaded frozen crankshaft position sensor, which was very deceiving in the beginning because after removing the sensor hold down bolt , I was easily able to rotate the sensor back and forth in the bracket. What I realized later was the outer metal body of the sensor had remained frozen within the bracket and the sensor was rotating back and forth in this metal body. After spending entirely to much time trying to free the sensor I inevitably ending up breaking off the head of the sensor, leaving behind the frozen body within the bracket.
So being faced with spending hours trying to pick and prod with limited access or (having no lift) finding a shop I felt comfortable enough letting some stranger put his greasy paws on my beloved W124, not to mention incurring the shop expense and towing expense and being unable to cruise around in my sweet W124 V8 "yeah what's up beeach", I ended up stumbling on this procedure. I wish I had pics but I was unsure how this would workout
I personally have found this forum to be an invaluable asset, so I wanted to share my "workaround" for replacement of frozen CKP sensor, in the hopes that it may possibly help another member, if one should choose to use this procedure.
Procedure:
First thing I did was order a replacement CKP sensor bracket. I found a used one @ R129 website. This arrived with both the top and bottom locating bushings preinstalled, but being a used part it was a bit greasy so I removed the bushings and cleaned these three pieces up. Once the parts dried I put a small drop of Loctite on each bushing and reinstalled them into the CKP bracket and then I set this sub assembly aside to dry and headed to the car.
At the car I had previously removed some of the plastic bits from the false firewall, throttle linkage bracket (swing out of way), and the coolant hose on the back of engine, to free up some space to work.
Then with a bit of patience I used an open end wrench to remove the top bolt from the CKP sensor bracket. A telescoping magnet comes in handy throughout process. With the top bolt removed I very carefully drove a wedge between CKP sensor mounting flange and the bell housing flange. This required a few very light taps with a hammer. Driving this wedge in causes the CKP sensor bracket to break at it's weakest point which is the centerline of the lower bolt hole on the bracket.
I was then able to remove the old bracket which in turn then left access to the CKP sensor bracket's lower bolt. Next I removed the lower bolt being careful not to drop any bits. With the lower bolt removed I was able to install the replacement CKP sensor bracket using the alignment bushings to locate the bracket exactly where it should be. And finally I installed the upper bolt into the bracket with a couple drops of Loctite applied to the threads of the bolt. With the replacement bracket secured I installed the replacement CKP sensor and the other parts that were removed for better access. " Dishes are done man"
In my opinion this one bolt will provide sufficient clamping force and the alignment bushings will prevent the bracket from walking out of position and off course if I remove the transmission for whatever reason I will reinstall the lower bolt into the bracket. This is relatively painless procedure versus trans removal or picking and prodding for hours on end.
I actually had a guy lined up to r&r the transmission for me but he was so busy with other work I got impatient and I figured what do I got lose, if this hadn't worked out no big deal, But yay it did, picture me rolling
!
Scott
I was lucky enough to find myself with the dreaded frozen crankshaft position sensor, which was very deceiving in the beginning because after removing the sensor hold down bolt , I was easily able to rotate the sensor back and forth in the bracket. What I realized later was the outer metal body of the sensor had remained frozen within the bracket and the sensor was rotating back and forth in this metal body. After spending entirely to much time trying to free the sensor I inevitably ending up breaking off the head of the sensor, leaving behind the frozen body within the bracket.
So being faced with spending hours trying to pick and prod with limited access or (having no lift) finding a shop I felt comfortable enough letting some stranger put his greasy paws on my beloved W124, not to mention incurring the shop expense and towing expense and being unable to cruise around in my sweet W124 V8 "yeah what's up beeach", I ended up stumbling on this procedure. I wish I had pics but I was unsure how this would workout
I personally have found this forum to be an invaluable asset, so I wanted to share my "workaround" for replacement of frozen CKP sensor, in the hopes that it may possibly help another member, if one should choose to use this procedure.
Procedure:
First thing I did was order a replacement CKP sensor bracket. I found a used one @ R129 website. This arrived with both the top and bottom locating bushings preinstalled, but being a used part it was a bit greasy so I removed the bushings and cleaned these three pieces up. Once the parts dried I put a small drop of Loctite on each bushing and reinstalled them into the CKP bracket and then I set this sub assembly aside to dry and headed to the car.
At the car I had previously removed some of the plastic bits from the false firewall, throttle linkage bracket (swing out of way), and the coolant hose on the back of engine, to free up some space to work.
Then with a bit of patience I used an open end wrench to remove the top bolt from the CKP sensor bracket. A telescoping magnet comes in handy throughout process. With the top bolt removed I very carefully drove a wedge between CKP sensor mounting flange and the bell housing flange. This required a few very light taps with a hammer. Driving this wedge in causes the CKP sensor bracket to break at it's weakest point which is the centerline of the lower bolt hole on the bracket.
I was then able to remove the old bracket which in turn then left access to the CKP sensor bracket's lower bolt. Next I removed the lower bolt being careful not to drop any bits. With the lower bolt removed I was able to install the replacement CKP sensor bracket using the alignment bushings to locate the bracket exactly where it should be. And finally I installed the upper bolt into the bracket with a couple drops of Loctite applied to the threads of the bolt. With the replacement bracket secured I installed the replacement CKP sensor and the other parts that were removed for better access. " Dishes are done man"
In my opinion this one bolt will provide sufficient clamping force and the alignment bushings will prevent the bracket from walking out of position and off course if I remove the transmission for whatever reason I will reinstall the lower bolt into the bracket. This is relatively painless procedure versus trans removal or picking and prodding for hours on end.
I actually had a guy lined up to r&r the transmission for me but he was so busy with other work I got impatient and I figured what do I got lose, if this hadn't worked out no big deal, But yay it did, picture me rolling
!Scott
