I had Northridge in Silverdale, WA install 4.56 gears in my JKUR about 2 weeks ago. As I have reached the 500 mi mark of my break in I have increased speeds intermittently. At about 65-70 I get a slight pulse/vibration. I am taking the Jeep back to Northridge this Thursday for an inspection. Is this vibration somewhat normal since the drive shaft is spinning much faster now?

 

Anyone??

 

I just regeared to 4:88. No vibes at those speeds so in my experience that is not normal. I'm sure the will know.

 

Do you have lift on? How much? After market or stock drive shafts! I, believe if you changed to 4:88's and stock tires, then your ds would be turning faster! But, if you increased tire size then would be same or close too! I have 5:13's and turn 2500 rpm on my 35"? Duratracs! At 70mph.