vibration at 50 -55mph

onlyme44 · 07-28-2008, 10:40 AM

About 4 months ago I had a 4" super lift installed in my 05 rubicon unlimited. Now I didnt notice this right away. And I will also add that 2 months ago I got a motor bike and did not drive my jeep as much as normal. But driving at 50-55 mph i feel a vibration. It feels as if i have a bad U joint. I was under there and was not able to detect a bad joint. Now my lift kit came with the transfer lowering kit. This way I did not need the new drive shaft, or shafts. So back to the vibration...... Is there something I dont know about the lift and something I need to add, or is it a bad joint that I cant see, if so how do i know which one, front or back shaft, or has my shaft gone out of balance some how.

Thanks for the help,

Frank

valacech · 07-28-2008, 11:58 AM

If you installed the T/C drop I can't really see why you would have vibrations because of the lift. The drop is supposed to help realign the driveshaft and eliminate the vibrations. You may want to consider a 1" motor mount lift if the vibrations are coming from the driveline. Also, it is possible that your tires just need to be balanced or that you need an alignment after the installation of the lift. Get the tires balanced and the alignment done, if it continues to vibrate, check the angle on your rear driveshaft. If it's off, go with the motor mount lift as that should correct it.

onlyme44 · 07-28-2008, 01:16 PM

Im sure its not the tires. It a much higher frequency then what you would feel it your tires where out of balance. IT is what I have experienced when you have a bad U joint. Feels just like it.

Thanks

**Jerry Bransford** · 07-28-2008, 01:38 PM

4" of suspension lift is enough to cause drivetrain vibrations which if not taken care of right away, will quickly damage something like a seal, bearing, or u-joint. At the very least, get that t-case drop installed right away which will reduce the angles at the driveshaft u-joints that were increased by the suspension lift. If the 1" t-case drop doesn't take care of the vibes, it's time for a slightly longer CV driveshaft. Before buying the longer CV driveshaft (your Rubicon doesn't need a SYE kit) though, you could also try installing a set of 1" taller motor mounts which will add more angle correction much like the t-case drop does.

lecharbon · 07-28-2008, 01:52 PM

Exactly. Mine is already causing a slight leak out of the dif seal faster than I can save money to correct it. I have 4" of lift.

valacech · 07-28-2008, 01:56 PM

Take my and Mr. Bransford's advise on the T/C drop and the motor mount lifts. The CV shaft and SYE will cost $$$ as opposed to the motor mounts which are more affordable and may solve your problem.

jeep03girl · 07-28-2008, 01:57 PM

Did you replace the pitman arm? I had this same thing and was told that it was never changed....

onlyme44 · 07-28-2008, 01:58 PM

The transfer case drop kit is installed. It was put in with the rest of the lift kit. I was thinking of doing the new drive shafts and removing the transfer case lowering kit. But thats a lot of money and work if it does not work. But maybe the engine lift you spoke of would be a try. Can you tell me where to get this. I have not seen this anyplace yet.

Thanks

onlyme44 · 07-28-2008, 02:03 PM

The pitman arm was changed. A drop one came with the kit. But it cause me some problems. So with the advice from the guys in here I changed to the original and the problem went away and all was good for a while till this vibration thing started up.

**Jerry Bransford** · 07-28-2008, 02:09 PM

1" taller motor mounts are available from several sources including Brown Dog (a JF vendor), or from Mountain Off Road Enterprises as is installed on my TJ. Make sure to choose the rubber mount version over polyurethane to minimize engine vibrations getting past the mounts.

onlyme44 · 07-28-2008, 02:39 PM

I just called Mountain off road enterprises. They told me I would have to put in a body lift to be able to put in the engine mount lifts. So Im bach to square one.

**Brown Dog** · 07-28-2008, 02:46 PM

Quote:

Originally Posted by onlyme44

I just called Mountain off road enterprises. They told me I would have to put in a body lift to be able to put in the engine mount lifts. So Im bach to square one.

Sorry to disagree, but a body lift is NOT needed to install a 1" MML. You simply need to relocate the fan shroud by drilling new holes in it (not the radiator) so that it will align with the fan.

onlyme44 · 07-28-2008, 02:58 PM

Thanks for the info. I may take you up on the mounts.

Frank

valacech · 07-28-2008, 03:11 PM

Even if you did have to do the body lift, that's a piece of cake. Just get some beer and have a few buddies help you out.

**john NC** · 07-28-2008, 03:20 PM

Quote:

Originally Posted by valacech

Even if you did have to do the body lift, that's a piece of cake. Just get some beer and have a few buddies help you out.

yeah it's really easy, i did mine with the stock bottle jack and a scrap piece of wood in about an hour (i'd never done one before)

and it's a lot cheaper than fixing the damage driveline vibes could cause