2024 rubicon x vibration after gears

[JT Nate]

Hello all! New to the forum and new to posting on forums but I’m at a lose. I’ve read many threads and feel with the 24 and no FAD there’s a new issue…. Here we go

2024 rubicon X. Just got a 3.5 Clayton overland plus lift on 38 x 13.5 nitto trail grapplers. Also got an Adams 1350 CV driveshaft and rock jock drop spacer. All is good. No vibrations. I get 5.13 gears installed and feel a pulsating 1 sec vibration through the floor while going 60 on the highway. Take it back to the shop that did the gears (different shop that did the lift) and they stated they think I have a defective Adams driveshaft since it’s throwing grease and said it had a little more play than usual at the double cardan joint. About to ship the driveshaft back to Adam’s and through the countless forums I feel it’s more a caster issue without having a FAD. There is no vibration with the front drive shaft off. Should I take it to the original shop that did the lift and have them adjust the caster to 4 1/2 and see if it takes the vibration away? Or send back the driveshaft first? Kinda of a new issue since they just recently removed the FAD. Kinda wishing they kept the FAD. Sorry if I missed a thread already.

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[Hootbro]

You running Yukon Gears?

 

[JT Nate]

You running Yukon Gears?

I got Dana spicers. Gears are nice and quiet. It’s a very small vibration might I add. Enough to drive me crazy though on the highway

 

[Stan H]

I got Dana spicers. Gears are nice and quiet. It’s a very small vibration might I add. Enough to drive me crazy though on the highway

If your Caster is only 4.5 its probably too low . 5.5-6.0 is where most end up.
Do you have adjustable lower control arms ?

 

[JT Nate]

If your Caster is only 4.5 its probably too low . 5.5-6.0 is where most end up.
Do you have adjustable lower control arms ?

It’s in that sweet spot now. If I had a FAD it wouldn’t be an issue. But since my driveshaft is always turning it doesn’t like the angle from the front differential in the 5.5-6.0. If it was lower, than my driveshaft/ differential angle would be inline. But now my steering will suck. That’s my dilemma. With the FAD that angle wouldn’t matter cause at low speed 4wd there’s no vibration.

 

[Stan H]

It’s in that sweet spot now. If I had a FAD it wouldn’t be an issue. But since my driveshaft is always turning it doesn’t like the angle from the front differential in the 5.5-6.0. If it was lower, than my driveshaft/ differential angle would be inline. But now my steering will suck. That’s my dilemma. With the FAD that angle wouldn’t matter cause at low speed 4wd there’s no vibration.

But you lifted it . So now your axle is back further than stock. I bet you need more that dont sound correct.

 

[JT Nate]

But you lifted it . So now your axle is back further than stock. I bet you need more that dont sound correct.

All adjustable control arms. The angle is at 5.5. Are you assuming it was just lifted with non adjustable control arms and is sitting at at a bad caster? My gladiator handles great…that’s not the issue. It’s lifted but adjusted. Im definitely no expert… but from what I have been reading in the forums is that you’re right about the sweat spot for caster (which I am at) when it comes to steering and not having to fight side to side movement when driving. But the higher caster moves the differential angle in the wrong direction. By lowering the caster angle it will put the differential in line with the driveshaft. Either way I’ll have the shop set the caster to a in line angle and see what that caster angle is. I guess all the guys with the 392 (no FAD). Resolved this issue with the lower caster around 4.5-5.

 

[Muddyape]

2021 Rubicon, Clayton 3.5 inch lift, Fusion D60 axles with 5.13’s, BFG 39’s and 5.5 caster. At 60 to 65 miles an hour “little” vibration (more a sound than a feeling) and ive gone through it a dozen times. Caster, pinion angles etc. all is in spec. So, if you figure it out I would love to know but honestly I have relegated myself to the notion that if you F around, you move the line for what is/should be normal.

My toe in is just shy of 3/16. I originally spec’d to steer smart (almost 1/4 toe out) and it floated all over

I have a ton of weight in the ass as well, smartcap, rtt, decked system and when I accelerate it will squat and lighten up the front end. Should have just stated with my WRX

 

[Badunit]

Adjust the caster so the driveshaft and axle are in line, or closer to being that way. Test drive. If the vibration is still there then it is probably not that. Adjust it back to where it was. I don't have adjustable control arms but if it does not require removing the control arms to make the adjustment, you should be able to do this test yourself without a shop. You could do it either way but the difficulty increases if you have to remove/reinstall control arm bolts.

 

[LouisvEarlleJT]

Sounds like a driveshaft issue.
I had a vibration issue on a Camaro once and tracked it back to the driveshaft yokes being out of alignment.

vibration gone.

 

[JT Nate]

But you lifted it . So now your axle is back further than stock. I bet you need more that dont sound correct.

 

[JT Nate]

Adjust the caster so the driveshaft and axle are in line, or closer to being that way. Test drive. If the vibration is still there then it is probably not that. Adjust it back to where it was. I don't have adjustable control arms but if it does not require removing the control arms to make the adjustment, you should be able to do this test yourself without a shop. You could do it either way but the difficulty increases if you have to remove/reinstall control arm bolts.

Good idea. All within my capabilities. Just got a Klein level to check angles as well. Was gonna go through the shop since their work is under warranty and they can do an alignment. But like you said if I’m equally adjusting the he control arms a little at a time I shouldn’t need an alignment right?

 

[JT Nate]

Sounds like a driveshaft issue.
I had a vibration issue on a Camaro once and tracked it back to the driveshaft yokes being out of alignment.

vibration gone.

If adjusting the caster doesn’t work I’ll return the driveshaft to Adam’s. Thanks for the insight

 

[JT Nate]

2021 Rubicon, Clayton 3.5 inch lift, Fusion D60 axles with 5.13’s, BFG 39’s and 5.5 caster. At 60 to 65 miles an hour “little” vibration (more a sound than a feeling) and ive gone through it a dozen times. Caster, pinion angles etc. all is in spec. So, if you figure it out I would love to know but honestly I have relegated myself to the notion that if you F around, you move the line for what is/should be normal.

My toe in is just shy of 3/16. I originally spec’d to steer smart (almost 1/4 toe out) and it floated all over

I have a ton of weight in the ass as well, smartcap, rtt, decked system and when I accelerate it will squat and lighten up the front end. Should have just stated with my WRX

I’ll keep ya updated if I figure it out. Seems like the reason there was a FAD. Without it….its pick your poison. Hopefully I have this sorted out by tomorrow

 

[JT Nate]

So I got ahold of my alignment print out and found I was at 6.6 caster. Putting me at a 10.5 pinion angle. Talked to the guys at Adam’s driveshaft and they agree that angle is to steep. They said I should shoot in the 4’s for caster but might be able to get away with a caster of 5. So my steering shouldn’t be to bad. Should have everything done by Wednesday. I’ll update then! Hopefully I’m dialed in just in time for it’s first time out at badlands, IN

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