10 is the locking pin which holds the assembly in the nipple. Yes, I think those failures happened in my case. The bolt moves in and out with little or no resistance in either direction. I can jiggle the assembly in my hand and the bolt goes in and out.

Here's a very realistic scenario. The lock failed when my daughter started the car. The bolt was in the locked position when this happened. Let's say the wheel had been cranked over in one direction when this failure occurred. The wheel would not have been locked. She could have pulled out and started driving. Given the downward angle of the locking assembly, once the wheel got to the point where the bolt could slip into the column and lock it, it would have as the car was driving down the road.


Two additional items for any future readers of this thread:

1. The gauge cluster can be easily pushed out from behind by reaching up under the left side of the dash. No special removal tools required.

2. There is a misunderstanding on various threads on the general topic of stuck keys, locks, and ignition assembly removal. The pin which the dieselgiant tutorial shows being ground out is NOT the bolt which locks the steering wheel and it is NOT made out of hardened steel. It is the pin which holds the ignition assembly into the nipple on the column. Drilling it out does not require a dremel tool, but just a 1/4" bit in a standard drill. It is not difficult and only marginally more time consuming that pushing in the pin to remove the assembly.

The whole process is simple and should only take about an hour, perhaps less.

Remove the driver's kick panel.
Push out the gauge cluster
Unbolt the steering column and let it drop.
Drill out the pin
Remove the ignition assembly

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13