Help: Harsh Wheel Hop After Grizzly Locker Install

[EL_B_Zee07]

I've seen other people have similar issues with Grizzly lockers and wheel hop and I'm wondering how they've handled them. Truck is my daily driver 2007 CCSB leveled with torsion bars lowered almost all the way. I have Fox 2.0 shocks and 72" Longhorn Fab Traction bars. I've never had an issue with wheel hop until after the Grizzly locker install.

During 2 wheel drive launches (straight) that induce wheelspin the rear end starts to hop violently. I've scoured the forums and have seen everything from clamping the front side of the rear leafpack, the backside, or both. I honestly just think I should have gone with a TrueTrac, or left the g80 in, as like I mentioned before, I've never experienced a problem with wheelhop.

Does anyone have a Grizzly in their daily driver that doesn't experience wheel hop during wheel spin? Should I start by adding a little more preload to the traction bars? Should I put back the G80 (it's in fine working order) or see if I can trade/sell the Grizzly and get a TrueTrac?

I'm such a research first, ask advice second type of guy, and I'd like to thank anyone who provides input in advance....it's much appreciated.

 

[Blackmax123]

What air pressures are you running??

 

[EL_B_Zee07]

What air pressures are you running??

50 psi, front and rear sir. The 420s max psi is 50 so I'm running them at the top of their limit. Do you think unloaded I should be running lower pressures?

 

[TheBac]

Im curious how a differential change could cause wheelhop? How would that expose an issue with your suspension setup??

 

[OregonDMAX]

Have you experimented with different air pressures. I run my 420's at 42 because at 50 they ride like shit. Have you tried zero preload on the traction bars, i would atleast try it.

 

[PureHybrid]

What does the contact patch look like when it spins? Adjust air pressure based on that.

I don't see the grizzly being your issue, but stranger things have happened. Are you positive the stock carrier wasn't damaged?

 

[malar24]

I actually had this exact same issue with mine and I m running 420s as well. Spring clamps on the front side of the leaf pack seemed to help some with traction bars but. I ended up switching the traction bars out for caltracs to remedy this wheel hop as well as improve my 60'. Wheel hop is still there with the caltracs but less prone to happening vs the old traction bar setup

 

[Mike L.]

Aren't 72" traction bars made for sled pullers? Sounds like your back end is squating and allowing the rear tires to come up instead of the back end pushing the tires into the pavement. Just a rookie guess.

 

[Chevy1925]

Aren't 72" traction bars made for sled pullers? Sounds like your back end is squating and allowing the rear tires to come up instead of the back end pushing the tires into the pavement. Just a rookie guess.

if it was a 4 link rig, you would be onto something but these being leaf sprung, all the "traction bars" do is control axle wrap and then induce more/less load to the front end to lift it. the longer the bar, the more load is put to the front. unless his bars are flexing (which is possible now that he has more traction with the locker), the bars wont induce any hop.

im betting the fact the tires are so full of air, higher traction than what most of these trucks come with, shocks are having a hard time controlling spring rebound and the locker added both tires for traction FOR SURE now, its causing his hop.

axle wrap "hop" comes from suspension flex/movement that is not being controlled. its time to start looking for the weak link. a go-pro under the truck would tell you very quickly where the issue is.

 

[bfmine]

Aren't 72" traction bars made for sled pullers? Sounds like your back end is squating and allowing the rear tires to come up instead of the back end pushing the tires into the pavement. Just a rookie guess.

I was thinking kind of similar. But my thought was too much or not enough preload on the bars. Also that's just a rookie guess
Or maybe the leaf springs are "S"ing under load
A single bar to the bottom of the axle will depend on the stiffness of the leaf spring to "hold" the top of the axle
Whereas a ladder bar setup or a 4 link setup would hold the top and bottom of axle from rotating

 

[Chevy1925]

I was thinking kind of similar. But my thought was too much or not enough preload on the bars. Also that's just a rookie guess
Or maybe the leaf springs are "S"ing under load
A single bar to the bottom of the axle will depend on the stiffness of the leaf spring to "hold" the top of the axle
Whereas a ladder bar setup or a 4 link setup would hold the top and bottom of axle from rotating

at no point should you need "preload" in the bars. thats a good way to ruin your ride comfort and hurt the springs over time

 

[bfmine]

at no point should you need "preload" in the bars. thats a good way to ruin your ride comfort and hurt the springs over time

That's kind of what I was getting at. That's why I said too much or too little.
Maybe the bars were installed when the truck was on the lift. I can't say for sure. So I threw out a suggestion

 

[EL_B_Zee07]

Thanks for all the great responses guys. The contact patch looks exactly[YOUTUBE]dkrG_XY59AI[/YOUTUBE] like this gentleman. The Traction bars were on for months without any issue and were installed with the slightest amount of preload.

Mike L., thank you for your input Sir. I went with the 72" bars (they are the professional series from Longhorn with the 1/4 inch brackets and the bigger rod ends. They are 2 inch DOM, .200 wall with Chromoly rod ends that are apparently nylon injected/oil impregnated (if that's even remotely relevant). I researched a lot before purchasing and was between these and Flight Fabs bars. I wanted a Traction bar that was a jack of all trades, master of none for lack of a better term. Something quiet on the street (the professional series are completely noiseless), something that would aid in traction in the sand (I camp on the beach in the summer months), that could sled pull, and while they're no caltracs, something that wouldn't mind going down the 1/4 mile here and there.

The day of the Locker Install was when this issue started happening. As you see in the video the tires are leaving a patch that looks like = = = = for lack of a better visual. I have Fox 2.0 shocks on all 4 corners that are maybe 5 months old.

I've noticed that wheelhop is only evident when the tires are fighting for traction, as opposed to when I blow the tires off they spin freely with minimal hop. I'm going to try lowering my air pressure to 42 psi on all 4 corners as OregonDmax suggested and I'll borrow my buddies Go-Pro and get some footage of the pinion angle/movement during launches, as well as the leafs on both sides.

As far as messing with preload, that was my initial plan and to just very slowly add preload to see if it helped, but as Someone mentioned I have heard that's a recipe for losing your fillings if not executed properly.

I'd like to thank all the gentlemen who took the time to post, it's very much appreciated.

 

[bfmine]

Good luck Post up the video when u record it. Maybe we can help pinpoint it. Pinion angle looking at it from the side will be very helpful

 

[malibu795]

Which way did you preload the bars? Shoving the pinion down or up?
If one must preload should be shoving pinion down, or extending the bars.. as when you accel pinion rotates. upwards..
if they are collapsed for preloaded, pulling the pinion up, when you accel you risk, pending pre load amount, completely unloading the suspension as the pinion rolls up under acceleration

 

[EL_B_Zee07]

Which way did you preload the bars? Shoving the pinion down or up?
If one must preload should be shoving pinion down, or extending the bars.. as when you accel pinion rotates. upwards..
if they are collapsed for preloaded, pulling the pinion up, when you accel you risk, pending pre load amount, completely unloading the suspension as the pinion rolls up under acceleration

bars were installed with a very slight positive preload. Negative preload would negate the point of traction bars with under the axle brackets with the rotational force of the axle wanting to raise the pinion upwards, opposite that of the tires?

 

[malibu795]

bars were installed with a very slight positive preload. Negative preload would negate the point of traction bars with under the axle brackets with the rotational force of the axle wanting to raise the pinion upwards, opposite that of the tires?

If you're calling positive preload, as pulling/rolling pinion up, then yes you should have a negative preload, as the tq will force a positive role, and the traction bars are to eliminate or limit axle roll.

The wheel hop is simaltanious loading/unloading of the suspension.
On my old truck 02 cclb I ran ~1-2° pinion down from static ride height for preload. Any more ride quality drastically suffered

 

[EL_B_Zee07]

If you're calling positive preload, as pulling/rolling pinion up, then yes you should have a negative preload, as the tq will force a positive role, and the traction bars are to eliminate or limit axle roll.

The wheel hop is simaltanious loading/unloading of the suspension.
On my old truck 02 cclb I ran ~1-2° pinion down from static ride height for preload. Any more ride quality drastically suffered

Thank you for the information, it's very much appreciated.

 

[malibu795]

Should work better:thumb:

 

[EL_B_Zee07]

Lowered tire pressure to 42 psi and added slight preload to the bars. It was nonexistent before, but I truly believe that the added traction of the locker with 305/50/r20s was causing the hop. The wheels being in complete sync with each other seems logical to me that it could induce hop during wheelspin....but anyways, had to test it...

[YOUTUBE]Xj1pVi04efs[/YOUTUBE]