Hello,

The car is a 90 240 auto sedan, 175K, that I bought a few years ago and slowly refurbished it's mechanical issues. Among it's quirks were ball joints, possibly original, installed on the wrong sides, and brand new studded winter tires on the front wheels with summer tires on the rear. The PO said he was disappointed with it's winter performance.

It's moved about 3k miles since last January when I put it on the road. I did over everything on the front end, including a stiff lower steering shaft u joint. There was some play in it after getting it loosened up with Fluid Film. I've had to replace these on every 240 I've had, usually at around 200K.

A few weeks ago the looseness in the once tight steering caught my attention. I could also hear or feel a little bump when I gently rocked the steering wheel. I checked both wheels, which were fine, but there was some play in my new steering knuckle. I ordered a new one and the next day we made a planned 200 mile return trip to Montreal. The steering was worse than before we left so I laid the car up until the part arrived.

The first thing I noticed on disassembly was that the lower bolt had lost it's torque. Probably me, I thought. The upper bolt was fine and came with the effort I would expect it to require using 2 8" 13mm wrenches.

I didn't expect any trouble with the newly greased splines, but I had a screwdriver and a hammer nearby in case they were needed. I barely touched the screwdriver into the lower slot when one arm of the casting fell out onto the floor.



The only thing holding the thing together was the other arm which didn't look good at all.



There were cracks all over the place. I put a little dye penetrant on them to help see them. I thought maybe I'd over torqued them but I don't think so. The lower crack shown on the photo below seems to have initiated on the inside of the splinned hole, opposite to the bolt's pull.



This is the top section of the joint. It didn't fail but it was sure working on it. You can't see it, but the cracks go across the top.



I'm not an expert on aluminum alloys but my experiences with these is that it's not a brittle material. I've had to beat the living snot out of some of these and they've always deformed. Never chipped or cracked. As to the torque, the spec is 18 Ft lbs and it's possible I gave it a little more than that, but I don't tend to over torque. It's actually one of my pet peeves with mechanics who do.

Has anyone else experienced this ? I'm wondering if it's collateral damage from something else. The rack and steering column seem secure. Some of the cracks can only be seen under magnification. I checked the new one and I couldn't find anything.

Happy Holidays
Peter