'97 Taurus GL 147k: Bolts and Threadlocker


#1

One of the two bolts that holds the caliper mounting plate onto the knuckle sheared off and fell out of the hole today while I was busy installing a new stabilizer link in the background! I found the 2nd bolt only finger tight and narrowed in the center. It’s possible I overtorqued them upon reinstall during my ball joint project because I could never get them to “click” on the torque wrench (tried 3 times). Ford says these are M12x48 bolts (stamped 10.9 on the head) and they sell for $20 a piece!!! They’d have to be ordered. I tried locating replacements in town at several hardware and auto parts stores today but all I could find were 8.8 bolts.



Can I use the 8.8 bolts temporarily (say for a week) until I locate the 10.9 bolts? And does anybody know where I might be able to find these bolts besides Ford? I can’t believe I need to pay $40 for two bolts less than 2" long!



Also, should I put threadlocker on the 8.8 bolts (for a temporary install)? The 10.9 bolts had RED threadlocker on them, but I missed this upon reinstall and did not re-apply it. And how do you apply threadlocker? How wide a band and where?


#2

First, you have to make sure you get the right metric thread size. There is no M12X48 metric thread size. It should be more like M12X1.25 or M12X1.5.

The number on the head of the bolt is how the hardness of the bolt is designated on metric bolts. So a 10.9 bolt will be harder than an 8.8 bolt. And I don’t recommend installing a softer bolt in a brake retaining system.

Now on the thread-locker. You apply a couple of drops of the thread locker to the end of the threads of a CLEAN bolt before it’s installed. But now they’ve come out with thread lockers that aren’t liquid. But squeeze out like a toothpaste and are easier to apply.

Tester


#3

$40 for two bolts is painful… almost as painful as $75 for four new strut-to-knuckle bolts that were immediately removed and misplaced when the jokers doing my alignment put in camber kits!


#4

Colt Hero:
Are these the ones you are looking for. Available at my local schucks for $11.00.
~Michael


#5

Is this what you need?


#6

Find the bolts in the junkyard for a dollar.


#7

Tester,

Thanks for your reply. As bad as this new board is, at least it still retains quality posters like yourself. The decimal number that I neglected to mention is 1.75 (I think). Ford only gave me the M12x48 designation, but 1.75 is what was on the bin of the 8.8 hardness bolt that fit the caliper mounting plate. Haynes book says this is the Thread Pitch, or distance between threads in millimeters. As far as using the “softer” bolt, I guess I didn’t expect anyone to come right out with a ringing endorsement, but I was hoping someone would say they’d done that before for a short while and got away with it. These bolts are going through a smooth hole in the knuckle and into the caliper mounting plate. I know this doesn’t SOUND very good because if they both sheared off while driving, the caliper could fall out all together, but I wonder how much strength these bolts really need. I would think more of the force is on the caliper mounting bolts - but the sizes of these bolts don’t support my theory. The plate mounting bolts (SAE-wise, ~1/2"-5/8" x 1 7/8") are at least TWICE the size of the caliper mounting bolts (SAE-wisw ~3/8" x 1", also hardened by the way).

OK, just a couple of drops. The depiction on the package shows a wideish band completely around the circumference of the bolt near the end, implying several drops. I don’t know if I’ve got the “toothpaste” or the drops. Got it at Autozone for $5 (tiny .20 fl oz tube).

Dartman69, ok4450:

No - those aren’t the bolts. The smaller ones look like the caliper mounting bolts (which as I mentioned above are about 1" long), but those are different from the bolts that hold on the caliper mounting plate (which are twice the size).

Pleasedodgevan:

I guess the junkyard is always an option, but for a 10-year old car, those bolts could be weakened too and I may not be able to see it. Still, hard as it is to believe, that may end up being my only option.

There’s got to be some hardware megastore that carries these bolts. They can’t be custom-made for Ford…


#8

Found the M12x1.75x45mm 10.9’s today at an industrial supplier here in town. Had to buy a bag of 10, but they were still less than $6 for all 10! There are some minor differences, however, that I wanted to run by you guys:

1.) They’re called “black” bolts, not zinc or yellow zinc. Does that matter? They’re still stamped with the correct hardness. The originals are a dull silver/grey - which I’m guessing is zinc.

2.) The hex head does not have what I’ll call an “integrated washer”. The originals have the hex head which molds into a washer-like collar, then the stud begins. With these new bolts, there’s the flat hex head, then the stud starts immediately underneath. If I add a washer, it’ll be almost exactly like the original. Is there such a thing as a hardened washer, or can I just use the washers I purchased with the 8.8’s?


#9

Installed the 10.9 bolts this weekend - along with the hardened (black) washers I got from the same supplier. Used two drops of the red threadlocker on each bolt and torqued them down to 80 ft lbs (I think it was). I feel pretty good about this now. I DID end up using the 8.8 bolts for the entire week, driving very gingerly, not coming to any hard stops. Theses bolts came out looking pretty good, I thought. No signs of stretching or pitting, but maybe the naked eye can’t see whatever damage might be present.

Closing the book on the ball joint job. Thanks to Tester, ok4450, pleasedodgevan, dartman69, and macfisto.