Noise in cabin from RE control arms

[xjdavid1]

I have just fitted a 4.5" RE kit and now have resonant noise in the cabin above 60 mph. I suppect that this is coming from the control arms. I have the superflex arms with the johny joint at one end. Is this noise consistant with what everybody else is getting. I have BFG KO Allterains fitted so I dont have a lot of tire noise to drown out the noise from the arms.

[Kejtar]

Resonant noise from front control arms? Control arms would give you a creak/squeak on the rubber or a clunkt on the joints. If you have a rythmical joint, from the front, check your front driveshaft angle (if you have a locker in the front axle that is)

[xjdavid1]

But the control arms are connected to the diff which is connected to the driveshaft. The factory arms are not solid like the RE arms and have 2 rubber bushes instead of the RE 1.

[Kejtar]

But the control arms are connected to the diff which is connected to the driveshaft. The factory arms are not solid like the RE arms and have 2 rubber bushes instead of the RE 1.
OK... and your point is? The arms will not give you a resonant noise, they might cause something else to give it to you. Have yo uchecked your driveshaft angle up front? do you have a front locker?

[ZachMan]

not your CAs.

[bshaw]

rear d-shaft angle by chance? you'd be suprised, i'd check it if i were you!

[HotChiliRam]

x 2
I've just installed the RE SYE H&T and RE DS for my 242 and I have a Terrible noise at 65 to 75 MPH, but it only does it when accelerating, if I put the tranny in neutral the noise goes away.
I say check you DS angle, I'm pretty sure your noise is comming from there.
Have you installed a SYE?

[xjdavid1]

I have twin arb lockers and a SYE. My noise is the same. Worst about 65mph and disappears when I backoff. I have checked the rear DS angles but not the front as I cant change the front anyway apart from shiming the control arms out. I have had the front and rear DS out one at a time and the noise was still there. Maybe they both make noise because of the height of the vehicle. I do have plastic bushes in the top of the RE rear shakel which I wish was rubber but I doubt that is causing the broblem as I have tried with the rear DS out. Some of the noise does disappear when I take the front DS. I wonder what it would be like with the factory arms. There is very slight movement in the bearing in the front of the transfercase that I have been told is normal. Maybe with the extra height I am now at that this noise is coming from the slop in this bearing.

[ewander]

I had a similar problem. I would bet you that you need to adjust both driveline angles and/or ballance both drivelines....you may even have issues with the slip splines.

What year is your cherokee?

[xjdavid1]

Mine is a 95. Noise wasnt there before I lifted it. Rear DS is new and been balanced twice. The front spline is good. I suspect that the control arms are transmitting more vibration because there are solid and only have one rubber bush. Does anybody have a 4.4" RE kit who doesnt have this problem.

[Kejtar]

Mine is a 95. Noise wasnt there before I lifted it. Rear DS is new and been balanced twice. The front spline is good. I suspect that the control arms are transmitting more vibration because there are solid and only have one rubber bush. Does anybody have a 4.4" RE kit who doesnt have this problem.
OK, can you describe resonant noise better? Cause if it's something that's somewhat cyclical then I don't see how the control arms would be the cause of it being transmitted: the noise transmitted by the CA's would be more along the lines of various thunks resulting from you driving over things.

Some of the noise does disappear when I take the front DS
How much of the noise? I thnk that's a clue, and it's interesting that you actually have that noise because you have an ARB up front which means that your DS should not be spinning as you drive.

[Jeepin Jason]

Mine is a 95. Noise wasnt there before I lifted it. Rear DS is new and been balanced twice. The front spline is good. I suspect that the control arms are transmitting more vibration because there are solid and only have one rubber bush. Does anybody have a 4.4" RE kit who doesnt have this problem.

I've never noticed any increase in cabin noise due to the RE arms I run.

[53guy]

Try this. Check your angles like everyone else has said! I think it would be easiest to remove the front driveshaft completely and see if your vibrations are still there. It'll be your rear driveshaft at that point. If the vibes go away, reinstall your front driveshaft and try it again. You may also want to rotate your U-joint's 90 degrees and see if that helps balance them if you're confident your angles are correct and they have been balanced lately. If you removed your driveshafts to install the lift or SYE, the U-Joints may just be out of sync by 90 degrees.

[Rocketman]

I have this lift. NO NOISE. Resonance noise can come from almost anywhere on the vehicle even though it SOUNDS like the front. I'm guessing you have no SYE so you probably have low level hum/vibes from your driveshafts. Balanced or not if pinion angles are not good you'll get a "resonating noise."

[muduck18]

did you install the ARB's at the same time you lifted your jeep?

trust me... its not the arms... I have the same kit as you... not the arms...

when i installed my gears i got a noise simular to your description, because the pinion nut was loose... then because the angles were off...
Just because you have an SYE doesn't mean that your angle is fixed...
Did you put a shim in the rear axle? on a 4.5 lift you would need about 6 degree(i think, its been a while since i did that)

that all said... if you still think you are getting a noise other than that.. (my guess is you think its the CA's because it doesn't seem related to tire speed?) maybe check where the exhaust pipe goes over the transmission crossmember. if it is resting on the xmember it will make a loud noise in the cabin. (plus an obnoxious knocking), also could be the 4x4drive lever linkage... the rubber gromet wears out and it will make a sound like a grinding noise (plus an obnoxious knocking),

la de da.
I could go on for hours... doesn't mean I am right...
Good luck mate

[53guy]

Did you put a shim in the rear axle? on a 4.5 lift you would need about 6 degree(i think, its been a while since i did that)


6degrees? WOW! I've got about 7" in my lift and I'm only running 2.5degrees. You'll definately want to get a protractor and check it out. That's a whole lot of angle with a SYE in the rear. Remember, with the sye, the pinion needs to be about 1 degree below pointing directly at the SYE yoke.

[muduck18]

6degrees? WOW! I've got about 7" in my lift and I'm only running 2.5degrees. You'll definately want to get a protractor and check it out. That's a whole lot of angle with a SYE in the rear. Remember, with the sye, the pinion needs to be about 1 degree below pointing directly at the SYE yoke.

thats what RE sent me
thats what stopped the vibes
my 4.5in lift after almost 2 years a huge bumper and tire, still is sitting 6.25" above stock in the rear...

yes that is tru though pinion needs to point directly at yoke..

[kleake]

How much of the noise? I thnk that's a clue, and it's interesting that you actually have that noise because you have an ARB up front which means that your DS should not be spinning as you drive.

Not sure about you, but last time I checked my front driveshaft always turns,,, unless you have the vac disconnect, or different hubs installed....

But I do agree with everyone on here,, it's not the CA's... I have the RE 4.5" kit, and I get a clunking sound on some of the bigger bumps/potholes, but no resonating sound.... I agree,,, look for anything rubbing from the engine/transfer case/exhaust/etc.. to the frame.... On mine I mounted my sway bar disco's on the inside of the sway bar instead of the outside in order to clear the tires, but then they rubbed on the HD track bar bracket... After a little modification, my resonating sound went away.. I knew all along that is where it was coming from, but I had it that way just long enough that I knew my modified setup would work before hacking on my disco's.... BTW, I don't have any shims on my 4.5", SYE installed and yoke is 1 degree below transfer case... I do have 1.5" shackles that make up a little though.

[xjdavid1]

I have installed a 44 out of a TJ and I welded the spring perches on with the pinion facing the transfer case as in 0 degrees on the bottom uni. I know it probable should be down a couple of degree down but I doubt that is the case here. I have checked the exhaust for rubbing. I can feel a very slight vib which I suspect is causing the resonant noise in the cabin. I have measured the angle of the rear double cardin and it is 12 degrees or 6 degrees on each uni in the double cardin. I have tried putting 3/4" spacers to lower the T-case but did not help. I have not measeured the angle on the front diff pinion yet but I cant adjust that anyway as a have fixed length control arms.

[CRASH]

You want to keep your front adjusted for proper caster for handling purposes. I consider thi to be 3-5 degrees. Whatever happens to the driveline is of little concern, and secondary to the caster.

Cut and turn the knuckles if you want the front driveline correct, as that is the only solution other than locking hubs.

[xjdavid1]

What transfercase drop spacers is everybody using if any. I have tried 3/4 spacers but didnt help. I am going to try a few things this weekend.

[xjdavid1]

I have just noticed that the trac bar has a blue urethane bush in the bottom. I wonder if this is adding to the problem.

[HotChiliRam]

I use RE 3/4" spacers for the tranny and the RE H&T SYE with RE CV DS. As I mentioned above I had a terrible vib when I hit 65+MpH. Yesterday I took off my RE Degree Shims (4*) And the Vib is almost gone, I can barely feel it now.
Check for your Driveline angles, I'm pretty sure that that could be your problem.

HTH

[kleake]

What transfercase drop spacers is everybody using if any. I have tried 3/4 spacers but didnt help. I am going to try a few things this weekend.

I tried a transfer case drop of 1" while I was trying to get rid of my drive shaft vibs. It seemed like it made other things worse, but did not correct the drive line vibes. What I finally found was the bolt that holds my SYE on has a washer, and that washer had reshaped to a cone just a little. This let the SYE fit loose on the splines and allowed the double cardan joint to wobble just a tiny amount. After correcting this, the transfer case drop came out and all is good now. I do get a very small vibe about about 75 and up, but since that is above my normal range it's not a bid deal. Also, my DS splines are a little sloppy as my SYE and driveshaft have about 100K on them now... Also, with the transfer case drop on, my exhaust started rubbing lightly on my oil pan causing a funny sound too,, you might check there as well.

[Jeepin Jason]

if you run an SYE, DON'T run a t'case drop.

[HotChiliRam]

if you run an SYE, DON'T run a t'case drop.
In my case I'm using the drop's because I have MORE Tranny Mount and the Tranny gets very close to the body with out the Drop's. Plus I don't like the angle of the DS wothout the drop's.

[muduck18]

if you run an SYE, DON'T run a t'case drop.

he's right the tranny drop gets nothing if the rear has an SYE.

I have just noticed that the trac bar has a blue urethane bush in the bottom. I wonder if this is adding to the problem.

Not likely.

how did you align the axle when you put the Track bar on? Did you center it?

you say the rear is an axle out of a tJ? is it centered in the back? if the angle of the drive shaft is on but they don't line up right you can get a noise/vibe.

does the noise pulse in and out? like a whurring that comes and goes consistantly?
if it pulses you have more than one problem and you can rule out bushings and stuff...

[kleake]

if you run an SYE, DON'T run a t'case drop.

I agree, but I was just trying to get my rear joint in line a little better by trying a few different things to see if I could get my vibes down. Wasn't planning to keep the drop, but if it helped or eliminated the vibe, then I knew shims were going to be the correction, I just didn't have any on hand. As a rule, I try to stay away from any TC drop if possible as it changes your alignment on linkages, fan and many other things... Usually not a major amount, but it also reduces your ground clearance...

[xjdavid1]

I did centre the front axil when I put the adjustable tracbar in and I also centred the rear axil when I fitted it. I have just fitted the 3/4 TC spacers that came with the RE kit. After looking at the specs for maxium speed and uni angles I noticed that the maxium recomended speed for a uni with 6 degrees (I have 12 degrees on the double cardin without the spacers) is 60mph. So I am right on the limit. Dont know if this has anything to do with my noise. The noise is still there. I have also tried fitting 3 degree wedges to turn the diff down a bit which is what it needed. I havent measured the angles. The noise is consistent. It is first heard about 30mph as a growl and then builds to a hum at 60mph. There is a minor vibration in the car not the steering wheel. It shakes some loose fitting in the car. So at this stage I might get my DS balanced for the 3rd time as it seems that maybe something is out of balance. I still have to measure the front yet but I dont think that is it as the noise is only there when I accelerate even very lightly which rules out the front as it is not driving. I have a MIT SYE so hopfully the nut is still tight. I have checked it at one stage.

[53guy]

hmmmm.....

[xjdavid1]

Just measured rear diff pinion angle to be 2.5 degrees below DS. I have 3 degree wedges probably should get 2 degree wedges. It is definatly the rear DS as I put the rear on stands and spun the tyres in gear to 100kph. I can feel the vibration in the car at about 55 mph.

[53guy]

I would say try to get the pinion angle about 1.5 degrees below. That's what I have and I don't get vibes until around 90mph or so which is pleanty for me. Also, I was thinking last night and maybe its a good idea to get the tires balanced if they're not already. You may have thrown a weight on one tire without knowing it. Or if the driveshaft is not new, but has been balanced, check the U-Joints to see if they are worn or old.

[xjdavid1]

Driveshaft is new and tyres have just been balanced. I will buy some 2 degree wedges next week. I reckon the vibration is coming from the double cardin as the vibration is a heavy sounding growl at lower speeds and a vibration as well at higher speeds. I think I will get the DS checked out again. I may be able to swap the front and back DS some time to test as well.