Bolt broke off

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BoulderJeff

BoulderJeff

10 Year
Joined
Mar 31, 2015
Threads
14
Messages
104
I noticed that my FJ is pulling left and right when I'm breaking or hit a bump so I took a quick look at the front end and noticed this bolt has broken off. Looks like some grease is leaking out too. Has anyone experienced this? I'm guessing this isn't an easy repair since it's part of the housing. Is this a job for a machine shop/welder? Can I live with 3 bolts?

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If grease is leaking out, you might have gotten lucky and the stud just backed out.
 
I do not think it would be advisable to drive with only 3 of the 4 studs.
 
You need a new stud, cone washer and nut. Do not drive it until you replace them. Then if you're not up for it, get someone to rebuild your knuckles.
 
Full axle rebuild isn't really required. Just get a new stud in there, tighten them all up and drive. I wouldn't drive it until you get a new stud in it. You could probably use a full axle job, but that's not really a safety issue.
 
BoulderJeff said:
Can I live with 3 bolts?
Click to expand...
Do you like to have the ability to steer?
From the picture it appears that the lower bearing cap (the plate that is secured by the 4 studs/cone washers/flat washers/nuts) is starting to separate. This tells me that the 3 remaining fasteners are loose as well. If that's the case, you have a strong possibility of failure.
 
And check the torque of the nuts on the passenger side as well. 71ft lbs
 
If you are someplace and NEED to get home or to a shop, you can tighten the remaining (3) studs/nuts, then drive home, but take it easy. I actually discovered this on mine when one had broken off, two fell out, and the fourth was in there less than finger tight. I snugged it up and drove 14 miles home GENTLY.

I bought new studs, nuts, cone washers and replaced them as soon as possible. The studs thread into the ball of the knuckle and the back side are open into the ball.

There are LOTS of threads on this topic, search "knuckle studs" and there is some debate on torquing in the studs VS not torquing as well as using or not using Loctite. Make your own decision there. Do you need a welder for this fix? No. Just a jack and stands, pull the wheel for easier access, and some basic hand tools and a pair of Vise Grips. And a deadblow hammer.

Buy enough stud kits to do both sides, so (8) total.

@Tools R Us has good input on this rebuild, look for his threads.
 
Thanks everyone! This was very helpful. I went from total dispare to a $20 fix!

I climbed under and the 3 nuts were very loose. I tightened those down for now and the lower bearing cap mated back up and squished out some grease.

I ordered a set of studs, nuts and lock washers and will replace this weekend.

Thanks again!
 
If you didn't already order it you'll be missing a cone washer as well.

Make sure the threads in the hole are in good shape, and clean the lower knuckle and steering arm surfaces really well before reassembly. It is easiest to do this when all four studs are out. The friction between those two parts is very important to avoid stressing the studs in the future.

Also as discussed recently, the studs don't have a published torque when running them into the knuckle. Just "hand tight". The important torque number is what you put on the nuts after the arm is back on.

And I second @BILT4ME advice re: Tools R Us
 
I ordered 2 lock/cone washers, 1 stud and 1 nut.
I've done the knuckle rebuild before, but I don't want to take this all the way apart again. I may just loosen all the nuts, lower down the cap and clean as best I can and then tighten it all back up.
 
BoulderJeff said:
I ordered 2 lock/cone washers, 1 stud and 1 nut.
I've done the knuckle rebuild before, but I don't want to take this all the way apart again. I may just loosen all the nuts, lower down the cap and clean as best I can and then tighten it all back up.
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I sincerely hope you checked the other side as well.
And why you didn't order a complete set of hardware is beyond my comprehension. The remaining studs could be damaged from the housing twisting on itself and this stuff costs nothing.
 
You now are aware of some of the most critical nuts to check before leaving on a trip. I call it my pre-flight stud, nut and fluid check and its done before starting any adventure.

I also mark all my nuts so that I can easily check to see if they've backed off at all.
 
Since this seems to be a common problem with these nuts, and studs coming loose I'd do this. When you clean everything up, and put it all back together I'd do one more step. I'd paint some witness lines not only on the nuts, and studs, but the steering linkage too. This way if anything loosens up, you'll easily be able to see it, because your witness paint lines will no longer line up. So each time you change your oil, make it a point to check your witness lines as part of your PM program.
 
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Why not castle nuts? Safety wire? Those little plastic indicators truckers use?
 
mct75 said:
Why not castle nuts? Safety wire? Those little plastic indicators truckers use?
Click to expand...

Because it's not likely to do any good. The leading failure is lost fastener tension due to ether; stud stretch (from a big load event) or parts stack up shrinkage (most often from uneven surfaces, burrs, debris, rust, paint between parts when assembled). So when the event starts, the fasteners don't turn, tension is lost in other ways, fastener locking devices are ineffective and add a false sense of security. The best plan is occasional torque check, especially after doing any work that involves that hardware.

I would replace all 4 studs on that side, they are likely stressed and will not hold rated load.
 
SmokingRocks said:
You now are aware of some of the most critical nuts to check before leaving on a trip. I call it my pre-flight stud, nut and fluid check and its done before starting any adventure.

I also mark all my nuts so that I can easily check to see if they've backed off at all.
Click to expand...

All my critical nuts and caps are painted bright orange, that way if I'm still half asleep, they are easier to locate.
 
I either paint the face that is towards the front of the rig green or I get a punch a put a dot on the leading face of the nut.

That way I can get a quick reference if anything has loosened just from looking under the front of the rig.
 
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