Another vibration thread (1 Viewer)

[NCjeff]

Just trying to get some more suggestions so I get really overwhelmed and confused.

97 with 313K miles, no idea about previous services. NEW Slee 4inch lift, removed sway bars, DC front driveshaft. New 37 inch tires. All professionally installed by WELL known 4x4 shop.

So drives fine NO vibrations around flat / beach town. HOWEVER today I took it 3 hours away in the hills to wheel it and got very violent vibrations at acceleration only, at about 40 MPH. As soon as I let off gas they would stop. Put in Neutral, and checked driveshafts, no play, both solid as a rock. Tried to go easy on gas to go to trails and same thing happening in what appears only going uphill. So, when RPM are north of 2500.

So I turn flashers/hazartds on and drive 40-45MPH on the way home. When I get closer to home where the terrain is flat as a pancake. I could set Cruise control at 60, rev RPMS and only experienced the vibrations 1 more time. So I basically could not replicate them.

AND, now my check engine light is on…….

Any more ideas besides Ujoints ??

 

[cruzinfj1]

Have a vid by chance?? If it were me, I would get it up on four jack stands and check the ujoints again. If you cant see or feel anything, put someone in it and have them put it in gear. Go from reverse to drive, while holding the brake. Watch the rear slip spline, front and rear pinions, and the output shafts on the tcase as they shift.

You say its a new lift, but with the miles on it, Im betting it was an existing problem that has just been magnified by the change in geometry and tire size.

** Just wanted to add, look at the motor and trans mounts also **

 

[robnicko]

as per above, check the rear slip joint. Best to remove it, clean out all the old grease and re-grease with moly grease
Had a similar issue with mine a few years back and it was old hardened grease built up in the slip joint. once cleaned and re-greased has been fine since

 

[NCjeff]

Thanks y’all. That’s the plan tomorrow is really get into the rear driveshaft and see if that causing it.

 

[landtank]

Motor torquing and upsetting the driveline, maybe.

 

[mehbohdi]

In other words ^^^^ check your engine and trans mounts ^^^^ Start with the easy/simple stuff