New Twist on Lower Ball Joint failure

Great post Milo. That new design is exactly what I was thinking they would need to do to prevent the tension loading that Singtoe and I were discussing. Interesting to see that they ended up going that way; to me that suggests they realized they had a bit of a problem, and with the consequences so high, they forced a redesign. That new design looks much better, even with only 2 bolts instead of 4.

The bolts are under tension though, not compression. Either way, they are way bigger, and no doubt strong enough. If Toyota felt the need to redesign their joint, you can bet they did some testing to select/size the bolts properly.
 
Great post Milo. That new design is exactly what I was thinking they would need to do to prevent the tension loading that Singtoe and I were discussing. Interesting to see that they ended up going that way; to me that suggests they realized they had a bit of a problem, and with the consequences so high, they forced a redesign. That new design looks much better, even with only 2 bolts instead of 4.

The bolts are under tension though, not compression. Either way, they are way bigger, and no doubt strong enough. If Toyota felt the need to redesign their joint, you can bet they did some testing to select/size the bolts properly.

Tension is right because if you remove bolts with arm loaded, separation will occur.
 
I'm sure the bolt size/strength is more than adequate for the task at hand. Until, lets say the truck goes in for service and the mechanic uses his impact to r&r both bolts. Then you have a chance of them being over stretched from too much torque, or not being tightened enough. In either case you increase the chance of problems. If you loose one bolt out of 4 you are still driving home, if you loose one out of 2 you are going to have issues.

Again not saying this makes the new design worse than the old, just saying that it does have the same weakness as the old design, which is the human factor.
 
I'm sure the bolt size/strength is more than adequate for the task at hand. Until, lets say the truck goes in for service and the mechanic uses his impact to r&r both bolts. Then you have a chance of them being over stretched from too much torque, or not being tightened enough. In either case you increase the chance of problems. If you loose one bolt out of 4 you are still driving home, if you loose one out of 2 you are going to have issues.

Again not saying this makes the new design worse than the old, just saying that it does have the same weakness as the old design, which is the human factor.

IMG-20111121-00288.jpg~original
 
I don't know if it has been mentioned yet in this thread, but what is the proper torque to put on the ball joint securing bolts?
 
I'm sure the bolt size/strength is more than adequate for the task at hand. Until, lets say the truck goes in for service and the mechanic uses his impact to r&r both bolts. Then you have a chance of them being over stretched from too much torque, or not being tightened enough. In either case you increase the chance of problems. If you loose one bolt out of 4 you are still driving home, if you loose one out of 2 you are going to have issues.

Again not saying this makes the new design worse than the old, just saying that it does have the same weakness as the old design, which is the human factor.

Yeah, but the max load on these bigger bolts I'm sure is much higher than on the small bolts, so when you hit each with a couple seconds of air gun, which develops a torque closer to it's yield strength? The smaller one.

Check the FSM for the torque spec. It's in there.
 
Great post Milo. That new design is exactly what I was thinking they would need to do to prevent the tension loading that Singtoe and I were discussing. Interesting to see that they ended up going that way; to me that suggests they realized they had a bit of a problem, and with the consequences so high, they forced a redesign. That new design looks much better, even with only 2 bolts instead of 4.

The bolts are under tension though, not compression. Either way, they are way bigger, and no doubt strong enough. If Toyota felt the need to redesign their joint, you can bet they did some testing to select/size the bolts properly.

They have removed 2 of the 3 failure points...the nut and balljoint. The 2 bolts should be ok if torqued correctly.
 
LBJ FAilure

Just curious as I'm new to the site and owning a 4Runner. What is failing/ The mounting fastners, ball joint stud, or socket? Is it the result of a bad design or just wear? I've got 129K on mine and the front end seems tight with no unusual tire wear. :D
 
Just curious as I'm new to the site and owning a 4Runner. What is failing/ The mounting fastners, ball joint stud, or socket? Is it the result of a bad design or just wear? I've got 129K on mine and the front end seems tight with no unusual tire wear. :D

I would say bad design because if the socket fails due to wear it will fail catastrophically. You should jack up the vehicle and use a pry bar and check for play. With that mileage I would have them changed just for piece of mind.
 
on the other hand my originals made it 170,000ish miles before they needed changed (worn out, never did fail). I would say the fail safe part of the design sucked, but then if you can manage to do a few dollars worth of maintenance every 150k or so, you should never find out how well the fail safe part works.

I also wouldn't put much stock in the pry bar diagnostic method. If you have noticeable play with that little force, they probably should have been changed a long time ago.
 
just replaced mine with 240k on the clock , they were pretty bad and i didn't die.....but maybe could have?! either way i'd probably just do it and get it over with if you plan on have the truck for a long time
 
Hey folks,

Is this a common problem for 4x2 runners that have probably seen more street time than dirt?

Yep, as the mileage and age increase moving parts wear out. Lifts, and rough roads do increase the wear on the parts obviously, but if the front of your truck has any shimmy or shakes, fix it rather than assume its just getting old and you should be fine.
 
Thank you. So, the symptoms are pretty noticeable?

I thought so, but if you bought the truck with a worn front end, you may not know what it should feel like. Also I'm probably a bit more on the obsessive side since I've been working on cars in one way or another for a LONG time.
 
Well, I appreciate the advice. It's a 99 limited with about 125K miles on it. Dealer says there were no recall campaigns for my VIN.
 
Yes my CV broke(actually tore the boot differential end and seperated) and that is common, either for it to break closer to the spindle or for it to pull out of the differential.
 

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