Axle wrap - 2020 7.3 with 4.30 gears

[rhines81]

What exactly is happening mechanically during axle wrap and causing the hopping?

Simply said, not enough down force while trying to gain traction. The axle reaches a resonance frequency and the vibration can tear things apart. As said previously, the u-joints will definitely feel it. In the cab of the truck, you might not quite feel how violent it is due to the shock absorption and springs, but the axle and attached parts feel it.

 

[Stevenru720]

Currently planning a Tremor 7.3 build. Doing a Carli Setup with either the Add-A-Pack or full Deaver rear springs will remove that horrible stock lift block, which reduces the torque and leverage applied to the rear springs and will reduce wheel hop. Dan Torino from Carli has an article and video somewhere which explains this well. Axle wrap / Hop is one thing they greatly improve on. Of course, PMF also has a solution as others have noted.

 

[DalmerJD]

Am I the only one that does not like the idea of drilling several holes in your frame to mount PMF traction bars? Also, using self tapping bolts? What happened to good ol' grade 8 bolts?

 

[SManZ]

Interesting take from CJC Off-road on traction bars. Can anyone with a high end leaf spring and shock setup provide feedback?

Link to post,same as attached screenshot;

https://www.facebook.com/permalink.php?story_fbid=4713348812093495&id=144062389022183

I get hop in snow, especially when climbing my driveway. It's definitely annoying, but not sure I'm willing to throw thousands at it to make it go away.

 

[Birdhunter39]

Interesting from CJC. I surely don't want those backwoods redneck looking ladder bars under my truck. Our truck will be getting beach use once warmer weather gets here and i'm hoping this isn't an issue. If so i'll probably drop to a 2" rear block and hope for the best. Don't want to go any shorter than that though.

 

[GKMAG9]

All leaf springs get axle wrap, it's just the way the suspension works without having anything to prevent it aside from the spring rate itself. Traction bars and the roadmaster active suspension can help prevent it.

 

[Colfaxent]

Am I the only one that does not like the idea of drilling several holes in your frame to mount PMF traction bars? Also, using self tapping bolts? What happened to good ol' grade 8 bolts?

I installed a set of PMFs bars on my Tuned 6.4l approx 650 HP and 1200 ft lbs of torque because of axle wrap when pulling my 15000 lb 5th wheel. They were extremely well made and totally fixed the wrap issue. On top of that it made my trans shifting feel like butter. The length of the leaf springs on the Super Duty help with the ride quality but definitely low for axle wrap in high torque situations. As far as drilling 2 holes in each frame rail it has no affect on the strength of the frame or causing any issues. Grade 8 bolts are what are used to mount the brackets to the frame Not Self Tapping Bolts. If someone used self tappers it probably was because they didn't have the mechanical ability to get the bolts down through the inside of the frame! It's a tight fit and not easy but I was able to do it on the floor without a lift. Sounds like you haven't actually installed a set of these. PMF Suspension makes fantastic parts and supplies Superior Customer service. JMHO.

 

[armorross]

Does anyone have and/or suggest these options on their 23 MY Tremors?

 

[HeavyAssault]

@armorross : OneUpOffroad would be the best choice if you want to prevent axle wrap.

 

[armorross]

Ill look into that, TY

 

[Devenhallen]

Had it happen a bit in the sand dunes recently. I am going to need to find a solution, probably some taller springs to get rid of the lift block.

Springs don’t usually cure axle wrap. I have 11 leaf springs on a bronco and still get bad axle wrap.
The cure, PMF traction bars

 

[Devenhallen]

Interesting take from CJC Off-road on traction bars. Can anyone with a high end leaf spring and shock setup provide feedback?

Link to post,same as attached screenshot;

https://www.facebook.com/permalink.php?story_fbid=4713348812093495&id=144062389022183

I get hop in snow, especially when climbing my driveway. It's definitely annoying, but not sure I'm willing to throw thousands at it to make it go away.

I have 2.5” kings, 11 leaf Deavers which is the BEST of what he’s trying to describe and had to ditch it all and 4 link on a 200hp truck because axle wrap was so bad that it broke two yolks.
They’ve never hooked to a heavy trailer with Deavers if they think they’re not getting bad axle wrap.

 

[Devenhallen]

Am I the only one that does not like the idea of drilling several holes in your frame to mount PMF traction bars? Also, using self tapping bolts? What happened to good ol' grade 8 bolts?

Yes, drilling holes is no big deal and that self tapper is designed for what it’s doing. There is nothing better engineered than PMF traction bars and components.
Don’t want a self tapper, drill the hole out and use Grade 8 hardware. I’ll bed if you told PMf you wanted that they’d make sure you had it.

 

[BadDogPSD]

I wonder if I can find an old set of those "Lakewood" slapper bars that everyone was sporting on their hot rods in the 70's and 80's.

Oh man....they still sell those things new

Summit Racing SUM-770501 Summit Racing™ Traction Bars | Summit Racing

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Had those on my 69 Firebird!