Quick Question on Vibrations

Mazepam

TJ Enthusiast
Original poster
Joined
Aug 31, 2020
Messages
189
Location
New Jersey
Good Morning All!

So i have a quick question I changed my rear control arms this weekend, i don't have a SYE kit i have a 2.5 inch suspension lift and a 1 inch mm lift. I put the arms to the same length as stock so nothing has changed.

I notice though i feel a very slight vibration/ossicaltion through the steering wheel at all times when im driving, its not making my wheel shake its almost like I feel the engine vibrating.

However nothing else is vibrating if i let go of the steering wheel i feel nothing, i even drove around with a coffee cup in my cupholder up to 70mph and there are no ripples in the liquid.

Is this driveline vibration? OR would i feel it through the body if it was bad? This wasnt there before i changed the arms.
 
Good Morning All!

So i have a quick question I changed my rear control arms this weekend, i don't have a SYE kit i have a 2.5 inch suspension lift and a 1 inch mm lift. I put the arms to the same length as stock so nothing has changed.

I notice though i feel a very slight vibration/ossicaltion through the steering wheel at all times when im driving, its not making my wheel shake its almost like I feel the engine vibrating.

However nothing else is vibrating if i let go of the steering wheel i feel nothing, i even drove around with a coffee cup in my cupholder up to 70mph and there are no ripples in the liquid.

Is this driveline vibration? OR would i feel it through the body if it was bad? This wasnt there before i changed the arms.
That’s weird. Did you wait to torque everything until it was sitting back on the ground with weight on it?
 
i never had to remove the wheels i just did one at a time. But yeah i had them all installed kinda snugg, then i do the normal routine i jump up and down on different parts of the jeep and shake it around so it settles then torque everything up.

I'm totally fine with it, I just want to know if its possibly a driveline vibration even though i feel nothing through the body, as i said my coffee has no ripples in it whatsoever i just feel it through the wheel.

Could just be the MORE bombproof motor mounts vibrating more i notice it at idol and if I'm really giving it gas going up a steep incline, i always chocked it up to the vibration from the new motor mounts.
 
Ah ok pretty sure this is something related to the control arms because now my jeep pulls to the left when braking. Before i replaced my front control arms it would pull to the right, but now it doesn't do that.

After installing the rear it pulls to the left now. I guess i need to double check the lengths and stuff.
 
You need to get the tape measure under there and Insure your axles are mounted square.
 
Yeah for the new ones they are adjustable so i just lined them up with the stock ones and popped the bolts in on both ends to make sure they were the same length, maybe one of them twisted between me adjusting and installing or something im not sure. I'll take them both off and examine it.
 
This thread here the vibration feeling im talking about started after i installed 4 new rear control arms. I don't have a SYE so i installed them all to the factory length. Its most noticeable above 3rd gear.

Maybe its something in the bushings or something because as i said i feel nothing except when I'm touching the steering wheel, you wouldn't even know it was happening if your not touching the wheel. I'm not sure if that could be a driveline thing or a motor thing.

However yes i have noticed way more vibes since the MML especially under hard acceleration.
 
Is the MML new mounts or spacers for the original mounts? New mounts might be stiffer than the old ones.

Can you get vibes when not moving by revving the engine?
 
Yeah sometimes at idol it vibes especially after being driven I'm almost certain its caused by the mounts.

Just odd that these new vibrations just started after the control arms where installed but its only felt through the wheel. I'm going to make certain they are all the right lengthen when i get home tonight and report back.
 
Can't blame he driveshafts/control arms if you get vibes when you're not moving. Either stiff mounts or something's out of whack enough for the motor to make contact with the frame/steering shaft. Mostly likely stiff mounts but look around just to be sure.
 
Can't blame he driveshafts/control arms if you get vibes when you're not moving. Either stiff mounts or something's out of whack enough for the motor to make contact with the frame/steering shaft. Mostly likely stiff mounts but look around just to be sure.

Yeah the mounts are for sure stiff i know that's a common thing with MORE motor mounts there's a label about it on the instructions haha.

So really you don't think its my driveline if i cant feel it through the body? This only started this morning after the control arm install. Also i don't really notice it until I'm at around 3rd gear going over 30 mph or so.
 
I can't say that you have 0 driveline vibes, just that you have vibes from somewhere else (ie, motor mounts). You could have both. Get a feel for different rpms while not moving just to make sure.

Also, get up to speed where you feel vibes and push the clutch in and see how it feels at idle.

That said, 30 is pretty slow for vibes.
 
Yeah I'm going to do that on my way home. My brain is telling me its something with the length of the arms that I installed. But putting it in idol at higher speeds is a good test.
 
Ok so changed the transmission mount it was pretty dry rotted. Put the stock upper rear control arms back and lowered the t case by about 1/2 inch. The vibes are still there but only theough the steering wheel so im just gonna chalk it up to the engine mounts and forget about it