Track Bar Bolts Upgrade!

[Ospreyfe55]

So I’ve dealt with this before on a TJ and recently seen this talked about on FB. With most people using aftermarket Track Bars, the factory bolts are metric and most reputable TBs are American made and spec’d to SAE bolts. With that said
my recommendation for anyone is to get rid of those factory bolts in the trackbar and get grade 8 9/16”x3” bolts, washers and lock nuts. I had a lot of play in my track bar and swapped out the hardware. It made a noticeable difference in firming up the front end and was the cause of a steering shimmy.
For reference here are my measurements -
MC trackbar sleeve measured .5640” / 14.33mm. Factory bolt is .5440” / 13.82mm, Factory TB is .5580 / 14.18mm and 9/16” bolt is .5625” / 14.29mm.

Even changing the hardware to 9/16” will also benefit the OEM TB. Here is the list of hardware that I got from a local ACE as Lowes did not have the lock nuts.
Front Track Bar Bolts

9/16 x 3” Course Thread

2ea @ 3.19 (Bolts)
4ea @ .75 (Washers)
2ea @ .69 (Lock Nuts)

Total $11.52

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[WranglerAz]

Thanks for the post, I have a metal Cloak rear track bar sitting on my work bench to install. I will get those bolts too.

 

[CarbonSteel]

I am doing something similar but using flanged grade 10.9 fine partially threaded 16mm, 14mm, and 12mm bolts on all of the control arms, shocks, and trackbars.

For the front trackbar, the 14mm bolt measures 0.5511 leaving a gap of 0.006 which when combined with the partial threading should be much improved over the fully threaded OEM bolts.

 

[tengg2001]

is there a reason choosing coarse thread? The OEM bolt is M14 1.50mm pitch, which is a fine thread.

 

[Headbarcode]

is there a reason choosing coarse thread? The OEM bolt is M14 1.50mm pitch, which is a fine thread.

I recently upgraded all of my control arm, track bar, and shock mounting hardware to Metalcloaks new SAE hardware kit. It's all fine threaded bolts and lock nuts.

Fine threads offer more clamping force than the same diameter hardware with coarse threads. The tensile and sheer strengths are higher because the shallower cut threading doesn't reduce the minor diameter as much as coarse threading. This allows a higher torque ceiling on a fine threaded piece of hardware vs the same diameter coarse threading. Fine threads are less likely to back out and loosen from vibration, because the angle of the helical cut threading is lower per revolution than coarse threading.

The advantage of coarse threads are when threading into softer or brittle materials, like aluminum or cast iron. The deeper cut of the threads better resist galling or stripping, compared to the shallower fine cut threads. It's also harder to strip the threads off of a coarse bolt.

 

[tengg2001]

I recently upgraded all of my control arm, track bar, and shock mounting hardware to Metalcloaks new SAE hardware kit. It's all fine threaded bolts and lock nuts.

Fine threads offer more clamping force than the same diameter hardware with coarse threads. The tensile and sheer strengths are higher because the shallower cut threading doesn't reduce the minor diameter as much as coarse threading. This allows a higher torque ceiling on a fine threaded piece of hardware vs the same diameter coarse threading. Fine threads are less likely to back out and loosen from vibration, because the angle of the helical cut threading is lower per revolution than coarse threading.

The advantage of coarse threads are when threading into softer or brittle materials, like aluminum or cast iron. The deeper cut of the threads better resist galling or stripping, compared to the shallower fine cut threads. It's also harder to strip the threads off of a coarse bolt.

Thanks!
How did you change the nuts on Shock's frame mount? I remember the nuts are welded there. Plus, are you able to share the size of the SAE hardware's size?
I know the track bar is 9/16 - 3". What's the control arms and shocks?

 

[Headbarcode]

Thanks!
How did you change the nuts on Shock's frame mount? I remember the nuts are welded there. Plus, are you able to share the size of the SAE hardware's size?
I know the track bar is 9/16 - 3". What's the control arms and shocks?

Apologies, I forgot to specify that only the lower shock mounting hardware is in the kit.

The control arms were a blend of 9/16" and 5/8". I'd have to get back to you on the lower shock hardware. The box was kept to store the factory hardware, but it's stashed at work with all of my Jeep takeoffs.

Maybe @Metalcloak could provide a quicker answer?

 

[cosmokenney]

I recently upgraded all of my control arm, track bar, and shock mounting hardware to Metalcloaks new SAE hardware kit. It's all fine threaded bolts and lock nuts.

Are those all stock sizes? They don't mention them being oversized in any way. It just says they are for replacing the worn out stock hardware.

 

[Aquastream]

So I’ve dealt with this before on a TJ and recently seen this talked about on FB. With most people using aftermarket Track Bars, the factory bolts are metric and most reputable TBs are American made and spec’d to SAE bolts. With that said
my recommendation for anyone is to get rid of those factory bolts in the trackbar and get grade 8 9/16”x3” bolts, washers and lock nuts. I had a lot of play in my track bar and swapped out the hardware. It made a noticeable difference in firming up the front end and was the cause of a steering shimmy.
For reference here are my measurements -
MC trackbar sleeve measured .5640” / 14.33mm. Factory bolt is .5440” / 13.82mm, Factory TB is .5580 / 14.18mm and 9/16” bolt is .5625” / 14.29mm.

Even changing the hardware to 9/16” will also benefit the OEM TB. Here is the list of hardware that I got from a local ACE as Lowes did not have the lock nuts.
Front Track Bar Bolts

9/16 x 3” Course Thread

2ea @ 3.19 (Bolts)
4ea @ .75 (Washers)
2ea @ .69 (Lock Nuts)

Total $11.52

Will this help tighten up the steering and highway manners on a factory rubicon?

 

[AnnDee4444]

Can someone explain to me how this works? If the clamping force is enough to prevent the inner sleeve from moving, how would bolt diameter change anything?

I know many companies have there own proprietary bushing, but don't they all basically work like this? (@ 1:11)

 

[GATORB8]

Can someone explain to me how this works? If the clamping force is enough to prevent the inner sleeve from moving, how would bolt diameter change anything?

I know many companies have there own proprietary bushing, but don't they all basically work like this? (@ 1:11)

I'll watch after my meeting, but it looks from the preview picture that the bushing sleeve is sized smaller than the bolt hole. The pinch is supposed to grab the sleeve, which doesn't happen if it just sticks itself through the hole.

 

[Remorseless]

Can someone explain to me how this works? If the clamping force is enough to prevent the inner sleeve from moving, how would bolt diameter change anything?

I know many companies have there own proprietary bushing, but don't they all basically work like this? (@ 1:11)

It's never perfectly trapped and dead still, always some slight movement. It's why the bolt threads end up eating into the metal sleeve. Always enough movement to where sleeve/bolt mate up matters in limiting the movement. Also why smooth shank bolts are ideal, cause then you aren't slowly eating your bushing sleeve.

 

[AnnDee4444]

I'll watch after my meeting, but it looks from the preview picture that the bushing sleeve is sized smaller than the bolt hole. The pinch is supposed to grab the sleeve, which doesn't happen if it just sticks itself through the hole.

That's one of the "don'ts" from later in the video.

 

[AnnDee4444]

It's never perfectly trapped and dead still, always some slight movement. It's why the bolt threads end up eating into the metal sleeve. Always enough movement to where sleeve/bolt mate up matters in limiting the movement. Also why smooth shank bolts are ideal, cause then you aren't slowly eating your bushing sleeve.

Why wouldn't more clamping force be the solution here? What if the inner sleeve didn't move?

I get that the larger diameter bolt limits the amount that it can move, but only when the lack of clamping force allows movement in the first place.


Edit: in which case you would want a finer thread pitch as discussed in other posts above. Also thread lubricant.

 

[Remorseless]

Why wouldn't more clamping force be the solution here? What if the inner sleeve didn't move?

I get that the larger diameter bolt limits the amount that it can move, but only when the lack of clamping force allows movement.

I mean, there's only so much force you can put into it. At 190 ft lb your front LCA bushings still do this. You've got 2-3 tons of Jeep yanking and pushing and pulling on that bushing, especially when off road, so if 190 ft lb ain't doing it, how much more you willing to try and put in? Personally, I'd rather solve it with a better fit via a bolt vs torque.

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