I have a 1999 nissan Pathfinder that starts to vibrate at speeds between 60-65mph. I have had the tires balanced, and the u-joints replaced as well. The vibration is under the seats and not in the steering wheel. Could it be the front driveshaft? There is also a vibration when 4 wheel drive is engaged. Thans for your help

2007 Nissan Pathfinder Service Repair Manual INSTANT DOWNLOAD


to fix your car go to this link

Wheel balance problems usually occur at speeds above 40mph. Also check driveline u joints for problems, but these usually show up when taking off and vibration at lower speeds. Check wheel rims for being bent and tires that are free of bumps or out of round.

check for failing "U" joints, loose /binding slip joint check for bent drive shaft check for missing balance weight off shaft.

check the "u" joints for looseness and wear especially the front drive shaft . check sliding splines . The vibration is a harmonic vibration normally associated with worn "U" joints --bent or out of balanced ---worn /seizing slip joints or being excited by a failing drive thrust bearing in the diff. ( big bearing directly behind the pinion gear that takes all the load on drive) check the magnet on the diff drain plug for metal bits.

worn Struts can add to vibration

first have your wheel bearings checked,,jack up your car and wiggel the road wheels if there is a lot of flop in them have them done up,,,,but its very likley to be just road wheels out of balance,,,have them checked as well,,,,

Hm. I had an irritating vibration at highway speed with tires that came with my car. I had the balance checked and it was determined that there was an out of round tire. I replaced the tires, had them spin balanced, and the rims were perfect. After that, the vibration at highway speed went away.

Tires are the most common problem for vibration at various speeds.

Where did you buy your tires or have them spin balanced?

If the tires are round once checked on a balance machine to be true. Next check the driveshaft is a weight missing, dings or bent, u-joints loose?

Then check the rear ring

Check the ball joints and tie rod ends and Tire balance. Could have broken/slpped bet in a tire or whaeel migh have thrown a balance weight.

What are the condition of your tires? If their worn they can vibrate, also maybe have them high speed balanced. Most any shop can do that relatively cheaply. Also make sure your tires are speed rated for the speeds your driving.
Also keep in mind, especially with a 4 cylinder engine, the higher the RPM's, the more vibration your going to feel.