Everything you always wanted to know about LBJ bolts
- Thread starter Spiker Engineering
- Start date
Spiker Engineering
official vendor
Yup, that's what I would do. Torque them to 70 ft-lbs to get 9,000-10,000 lbs of preload, and still have tons of margin against yield torque.
Keep in mind that while ARP recommends 54 ft-lbs for these bolts, that's if using their Ultra Torque lube, which probably cuts the friction down by 30-50%. So 54 ft-lbs with the lube is probably similar to 70 ft-lbs dry.
jross20
New member
Sweet. I may go this path, maybe just to 65 ft lbs with blue loctite. But also after reading everything up here I definitely want to get some thread chasers and make sure those threads are cleaned out.
I wonder what the max torque that the spindle can handle is.
phattyduck
Elite Member
That's what I did... (70)
I'll be running sweep for a rally race in a week and a half, let's hope they hold up! :rapture:
-Charlie
shadow247
New member
I'd like to see some failure testing on the Knuckle threads. Seems like 70 is enough to potentially strip them out. I am running the ARP black bolts, but I went with 35mm instead of 30mm, which give me a couple extra threads engaged in the knuckle. The 30mm ARPs and OEM bolts were only hitting 2 threads when torqued.
I have been running the 35mm ARP Black bolts with Blue Loctite at 59 ft lbs for a while. Been on a few hard sends and so far, so good.
phattyduck
Elite Member
Are you running the ball joint protector? There seemed like plenty of thread engagement on mine...
-Charlie
jross20
New member
Really? Only two threads? That just doesn't seem like enough in my opinion. This is good information to know. Wouldn't you generally want all of the possible thread engaged?
Is there any downside to the 35mm length?
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shadow247
New member
They MIGHT bottom out in the captive part of the knuckle if you don't have the LBJ Guard that's on the 01/02. I'll grab a few pics so you can see what I'm talking about.
shadow247
New member
Yes that was with the LBJ protector. Did not have that concern on the 1999 that I did another set on.
jross20
New member
Now I'm stuck deciding between the red, black, and ARP.
Black does sound nice, but I do worry about the potential for someone down the road to torque it to 59 ft lbs. This problem would be avoided with red. ARP does not have these problems but I am nervous about using a non-oem bolt.
Perhaps red with a thread runner before hand and blue loctite.
Or maybe if I could add some kind of a sticker saying 37 ft lbs for the black bolt... Hmmmm
Black does sound nice, but I do worry about the potential for someone down the road to torque it to 59 ft lbs. This problem would be avoided with red. ARP does not have these problems but I am nervous about using a non-oem bolt.
Perhaps red with a thread runner before hand and blue loctite.
Or maybe if I could add some kind of a sticker saying 37 ft lbs for the black bolt... Hmmmm
Spiker Engineering
official vendor
I would not worry about the spindle threads. The spindle is forged, and the bolt will fail before the spindle does.
In all my tests, the bolts failed and the female threads did not (which is what one expects in a bolted joint of reasonably similar materials).
In all the bolts that I broke in testing, I was able to unscrew the broken portion from the female threads without a problem, indicating that the female threads were not damaged.
In the bolts that stripped (due to inadequate engagement), the bolt's threads were damaged, but the female threads were not.
I share the concern about engagement and torque values when you start mixing and matching non OEM components.
So as far as engagement, the OEM Red and Green bolts are 32mm long (the shank portion). They have plenty of engagement (if used without the protectors), more than a diameter's worth. Here is the Red bolt protruding through the LBJ, close to 8 threads:
But the 30mm ARP bolts will have two less threads of engagement. And if you add the washer (which I would), you are down to about 28mm of length, and only 5-6 threads of engagement:
In my testing, that was still fine at 59 ft-lbs. But as you increase the torque, the bolt's threads will strip, starting at about 80-90 ft-lbs. That's why I switched to 35mm ARP bolts, which when used with the washer, have about 33mm of shank. They protrude a little more than the Red bolts:
The Black bolts are 35mm long, so they protrude the most:
[MENTION=148218]JZiggy[/MENTION] made some measurements and ascertained that they will not bottom out even if used without the protector.
As for the torque values, I agree with the concern of someone possibly overtorquing a Black bolt at a future date. You can certainly add a label to it, but who reads labels? That is one advantage of the ARP, it can be safely torqued to 59 ft-lbs (or quite a bit more). Although I still like the smoothness of the Black bolt.
In all my tests, the bolts failed and the female threads did not (which is what one expects in a bolted joint of reasonably similar materials).
In all the bolts that I broke in testing, I was able to unscrew the broken portion from the female threads without a problem, indicating that the female threads were not damaged.
In the bolts that stripped (due to inadequate engagement), the bolt's threads were damaged, but the female threads were not.
I share the concern about engagement and torque values when you start mixing and matching non OEM components.
So as far as engagement, the OEM Red and Green bolts are 32mm long (the shank portion). They have plenty of engagement (if used without the protectors), more than a diameter's worth. Here is the Red bolt protruding through the LBJ, close to 8 threads:
But the 30mm ARP bolts will have two less threads of engagement. And if you add the washer (which I would), you are down to about 28mm of length, and only 5-6 threads of engagement:
In my testing, that was still fine at 59 ft-lbs. But as you increase the torque, the bolt's threads will strip, starting at about 80-90 ft-lbs. That's why I switched to 35mm ARP bolts, which when used with the washer, have about 33mm of shank. They protrude a little more than the Red bolts:
The Black bolts are 35mm long, so they protrude the most:
[MENTION=148218]JZiggy[/MENTION] made some measurements and ascertained that they will not bottom out even if used without the protector.
As for the torque values, I agree with the concern of someone possibly overtorquing a Black bolt at a future date. You can certainly add a label to it, but who reads labels? That is one advantage of the ARP, it can be safely torqued to 59 ft-lbs (or quite a bit more). Although I still like the smoothness of the Black bolt.
Spiker Engineering
official vendor
Oh and I would not worry about using non OEM bolts if it's something like an ARP, their reputations is solid. But I would avoid all non-branded Class 10.9 bolts.
phattyduck
Elite Member
That's a solid plan.Hmmm... Alright.
So 35mm ARP bolts with washers, clean the threads with a chaser or whatever it's called, then torque the ARP bolts to 62 ft lbs.
I ran my 30mm long ARP's without the washer or protector, so had plenty of engagement. The OEM ball joint surface is well machined and the bolts have flanged heads, I figured the washer wasn't needed.
-Charlie
jross20
New member
Oh that's a good point, does the washer effect preload?
jgue467
Senior Member
So on my '01 (its not nearby to see which month it was built but I think Sept), I've obtained the "black" bolts (90119-10933) and it had no dust shields from factory. Hoping these are OK and I'll keep them snugged under 40 as per all the info above.
So wondering if I should get those dust shields and if they really make a difference? Does it decrease wear?
This rig does about 50/50 on/off road, off roads are dusty, have dirt, mud, sand, the usual texas hill country findings.
So wondering if I should get those dust shields and if they really make a difference? Does it decrease wear?
This rig does about 50/50 on/off road, off roads are dusty, have dirt, mud, sand, the usual texas hill country findings.
Chuckles89
New member
On mine, both sides have been saved from sticks puncturing the LBJ boots because the shields have both been chewed up :shocked:
Spiker Engineering
official vendor
It might. The washer has slightly rounded edges, so the effective bearing diameter is quite a bit smaller than the full flange. Smaller bearing diameter = less friction loss under the head. So without the washer, you may lose more of the torque to friction, and end up with less preload.
jross20
New member
Interesting, I think you did the tests with the ARP bolts without the washer correct?
Spiker Engineering
official vendor
I started testing both configurations (with and without the washer) but then decided that the latter is dumb, so continued testing only with the washer. That hardened washer does a great job of preventing galling under the head, so I don't see why anyone would want to use the ARP bolt without the included washer.
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