Conflicting information for balljoint torque spec

I think he brought up the rubber shield because in another LBJ thread I had mentioned that I broke a brand new bolt (bolt/washer) when torquing them down to spec without the rubber boot. I figured maybe those two mounting circles on the rubber boot helped keep those two bolts from bottoming out in the spindle and that's why I snapped one

I ended up putting the rubber shield back on, got another OEM bolt and it went on just fine. I don't know if it was a just a bad bolt or if it broke because the rubber shield wasn't in place, but either way I'm not keen on finding out again. Getting the broken half out of the spindle sucked. Luckily I was able to back it out slowly with needle nose pliers.

 

Can you confirm that you used these 35mm length bolts?

https://www.mcmaster.com/95735A635/

 

Yeah, I could see where that might be possible with the two outboard bolts since they do not go through the spindle. The OEM bolts with a washer are longer than the flanged head bolts.

This looks correct, but I'll have to confirm later once I get back to my records at home.

 

Thanks. I appreciate it!

 

Those are the correct ones, yes. 35mm should not bottom out in the two blind holes either with or without the rubber boot guard. It’s always worth cleaning out as much of the threads as possible, to get any old Loctite, grease, or rust out of there to ensure the correct thread fitment.

 

Since we're on the subject of balljoints, does anyone run the Sankei 555's? I have a set on my lifted 04 Tacoma that I installed a few years ago. I just installed these lowers on my wife's 02 runner 2 weeks ago. I was told by my parts guy at my local Toyota dealership that Sankei is the manufacturer of bj's for Toyota. These come with the new mounting bolts.

 

They are the OEM manufacturer but I read that there is a large quality difference. Someone did a disection of both BJ and the afternarket one was very different internally. The OE is a full ball joint whereas the aftermarket one is only a half ball. I'm not in the position to pull up the thread at the moment but I believe the consensus is to just get the OE. But I'm glad it's working out for you.

 

^ that's what I was going to mention. That thread is very informative.

They are the manufacturer but the specs to which the ones for Toyota are made are different. That being said, a lot of people seem to run the 555 lowers and swear by them so, to each their own.

 

I did not know that. I'll research it and read that thread. On all my yotas I rotate the tires every other oil change and I check the bj's with a pry bar under the tires every time. So far no issues with the 555's on my Tacoma. I recently replaced my wife's because her t4r is at 145k miles and I read its recommended to change them at 150k for preventative maintenance.

 

I'm a auto tech by trade and I've installed 555's on all my customer's yotas and so far no issues.

 

This is more simple than what is being discussed.

Simply use the proper grade bolt of the correct diameter and thread pitch. Torque per specification.

Most torq specs are for dry threads, as soon as you put any liquid (locktite, anti-seize, butter, ....whatever) it is now a lubricated thread. The torq spec needs to be reduced to use the lubricated specification. This is common a path to over-torque troubles.

All fasteners at correct torque will "stretch". This stretch is what provides the clamping force to hold the parts together. If the bolt begins to YIELD, or stretch without return, then the bolt has failed. When the bolt is stressed within its tensile strength, then it will hold the parts. Beyond tensile strength the clamping load is gone. This is a fundamental property of steel and all materials.

Always use NEW replacement fasteners for critical applications. Bolts, nuts, screws are like engine oil. Cheap. A failure is much more trouble.

FWIW, a flange head bolt performs the same as a hex head/washer combination. It is easier for production assembly due to less parts need to be handled. A Grade 10.9, 10 x1.5, flange head will have the same strength as a Grade 10.9, 10x1.5 hex.

 

As Dan confirmed, the McMaster-Carr webpage you listed is to the correct bolt. I just confirmed my invoice displays the part number as: 95735A635. These are available as 10-packs. I paid $15.07 shipped for one 10-pack.

 

I think that the original question is if one should follow the FSM (59 ft/lb) or the Recall (37 ft/lb). I would argue the recall supercedes the FSM and thus 37ft/lb is the correct torque per page 7. I come from the aviation world. If the manufacturer came out with a fix, that's the way it's done from then on. Doesn't make any sense to replace the bolts holding the wings on, torque them to a new value, and then, the next time you work on them start using the old torque value again.

http://media.fixed-ops.com/Toy_Campaigns/50Jtech.pdf

 

UPDATE: So I changed out the passenger side this evening and did some experimenting. TLDR: Both McMaster and the original bolt did not stretch when torqued to 59ft/lb with blue loctite. Not sure how that person linked in the original post got them to stretch at such a low torque.


Picture 1: This is the OE bolt that I removed put side-by-side with a new McMaster bolt. As you can see, there was no stretching. However, we don't know if the factory torqued to 59ft/lb or 37ft/lb.


Picture 2: I put the OE bolt back in and torqued it to 59ft/lb with blue loctite. The bolt did not stretch after removing. Here it is comparing it to the McMaster bolt again.


Picture 3: Here is the Mcmaster bolt torqued to 59ft/lb with blue loctite compared to a new McMaster bolt. Again, no stretching.

 

I forgot to ask...it appears that you can't use the balljoint rubber protector with the flanged bolts. When you try to tighten them, it will start to tear. Is this protector critical? If not, I was planning to remove it. The only way I got them to not tear is if I put the OE bolt with the washer back in but I don't want to use old bolts since I already have new ones.

 

I like that you tested this theory, there's no better way to understand how something works than the scientific method. However, there are some underlying principles that will help in explaining what's happening here.

There are two types of stretching that might be seen in these bolts - either elastic deformation or plastic deformation. In elastic deformation, the stress in the bolt when it's torqued is lower than the yield stress of the material, and the bolt will be temporarily stretched when stressed (which provides the clamping force holding the ball joint to the knuckle) and then will return to it's original length when un-torqued (think elastic like a rubber band).

In plastic deformation, the stress is higher than the yield point of the material, and any load/torque above the yield point will result in permanent stretching of the bolt. This is commonly taken as 0.2% strain, so in a bolt that is 35mm long it would start to permanently deform once it reaches about 35.07mm - probably too small of a stretch to see with the naked eye.

Almost all bolts and machine screws are designed to stay below their yield point when fully torqued, with the exception of torque-to-yield bolts like head bolts. You should not expect to see any permanent deformation in the LBJ bolts, if you did that would be an indication to replace them.

 

The rubber dust shield isn't necessary. 1995.5 - 2000 1st gens didn't have them. They do help protect the LBJ boot though, from road debris and what not. But not necessary

 

Thanks. One of the hole complete broke and the other is barely hanging on. I'm going to undo the bolts tomorrow and just remove it. Then on the driver side, I'm not going to reinstall it. Thanks.