I just had gears installed and there is a distinct vibration at about 60 mph. The shop that installed them are stumped, they are suggesting replacing the rear drive shaft. They have no idea what the problem is...any ideas? Can it be the gears?

 

Did you do any other mods at the same time? Lift? driveshaft?tires? Based on some of my previous muscle car experiences, I try to do one mod at a time so that I can tell iff there is a problem. I used to have to wait months to get an appointment with my resto. guy so I would try to cram as much stuff in at a time. The problem is you can't tell which mod is causing the squeek/grind/etc.

I'm hoping this is not the case with your Jk. If you did gears and a lift at the same time,or the lift a few thousand miles prior, it has probably taken a few thousand miles for the driveshaft to start acting up. Good luck to you.

 

Thanks...the 2.5" lift was put on 10k miles ago. It would be a bizarre coincidence if the drive shaft failed the same time as the gear install. The problem is my tech has no clue what to do, he told he had no idea what could do it. I was hoping someone on the forum could shed some insight.

I had intake, exhaust and gears installed .... drove it in at 85mph as smooth as can be...picked it up. HORRIBLE vibration. Not a good day for me.

 

Did you check to see if he reinstalled the driveline correctly?

 

hows the air pressure in your tires, do you have any mud stuck on your wheels, tires, shafts......any rotating part? have you checked your lug nuts lately, are they loose? does the vibe go away after a certain speed or does it get worse, does it go away when you go slow

there are so many things that can cause a vibe it isnt even funny.

-shaun h

 

For real:

A lot of things can cause a vibration. As a Tire Center supervisor for Costco Wholesale, I can think of a couple tire/wheel related issues off the top of my head:

1. Improper wheel balance
2. Alignment off
3. Insufficient torque of the lug nuts (generating insufficient clamping force for the mating surface of the tire/wheel assembly and hub)


#3 is a major one. It's a sad state of affairs that a lot of tire shops out there STILL do not torque the tire/wheel assemblies after installation...that's just an accident waiting to happen

Russ D.

 

Well keep in mind that I drove her in at floored down the interstate at about 85 or 90 as smooth as could be, ZERO vibration. My lift (2.5") and tires have been on for about 10,000 miles or so with NO issues at all. Now one second after the gear install I am having issues. It has to be the gearsk, right? I just have no knowledge of what the gear install takes and what could go wrong. Are there seals, bearings, do you have to set parts at certain torques...no idea???? It just seems that it can't be the axle - - and my installers are stumped. AND, keep in mind, I am referring to the largest 4wheelparts installer in the country.

 

Hmm:

That IS curious...if you had zero vibration before the gear install and now it's giving you grief. I know that a re-gearing is one of the more complicated mods to undertake. If something wasn't tightened all the way, or something is sitting off kilter within the differential, I suppose it could transmit a vibration to the steering wheel. Hopefully it's nothing TOO major, because that's one of those maladies that could affect the rest of the drivetrain.


Russ D.

 

From what I've heard, the JK is more difficult to regear than past jeeps. So if he was impatient, the tech may not have shimmed the gears in right. When a gear install is done, they use a marking grease to check how the teeth of the gears are meshing together. They will adjust the shims to adjust the gear teeth contact so the teeth hit center to center. If the teeth mesh too high or low, then your jeep is going drive like hell.

Where is the vibration coming from front or back or both? Chances are he needs to reshim at least one of your pumpkins.

 

My .02! I had the same problem on my 2004 TJ. I drove to the gear shop and the rig was smooth as silk. After my 5.13s bad vibe. I did everything under the sun to loose the vibes since it was a daily driver! I hate to tell you, but the bottom line I found out was that with the lower gears the drive line makes many more revolutions at the same speed, thus magnifying any inbalances that are in the drive line. Perhaps a new drive shaft might help or re-balacnce the old one.