Fj 80 Vibration with acceleration

[danak]

Does anyone have experience or knowledge as to severe vibration of FJ 80 under acceleration. Begins at about 20 mph with severe vibration at the steering wheel and vehicle. With speed, the steering wheel vibration resolves but the vehicle vibration continues. Only seems to a curl while accelerating and not coasting. Wheels have been balanced, suspension checked. No loss of power or hesitation.
Thanks,
Dan

 

[ppc]

I suggest you inspect the U-joints.

 

[robnicko]

sounds like Ujoints or one of the slip joints is too full with grease.
remove one drive shaft at a time & lock the centre diff to test as front or rear wheel drive only to determine which shaft is the cause.

when mine did it the issue was old hardened grease built up in the rear slip joint, after separating it, cleaning and regreasing with moly grease its been perfect since.

 

[BucketEighty]

Sounds like drive shaft u-joint. Probably in the front shaft if you feel it in the steering wheel.

 

[danak]

Sounds like drive shaft u-joint. Probably in the front shaft if you feel it in the steering wheel.

Thanks. I’ll give it a look

 

[danak]

sounds like Ujoints or one of the slip joints is too full with grease.
remove one drive shaft at a time & lock the centre diff to test as front or rear wheel drive only to determine which shaft is the cause.

when mine did it the issue was old hardened grease built up in the rear slip joint, after separating it, cleaning and regreasing with moly grease its been perfect since.

Thank you!

 

[mudgudgeon]

Agree with above.
Once drive shafts are out, you should be able to rotate the uni joints freely in all directions.
If they stop before the uni joint components touch, or they feel stiff or notchy, time to replace them with genuine uni joints, not cheap junk.

When greasing uni joints, you should grease until you see fresh grease come out around all four bearing cups.
Cheap uni joints use rubber seals that push onto the outside of the bearing cup. When greasing cheap ones, once one of the rubber seals pushes off, grease takes path of least resistance, and you won't get grease into all the bearing cups.
Genuine uni joints use an oring contained within the bearing cup. Grease cannot push a seal off, so grease is forced more evenly through the whole joint.

Slip joints, need care to not over fill with grease

 

[Nad Aitch]

If you're a lazy arse you can get front and new OEM balanced driveshafts shipped to your door for under $900.

 

[mudgudgeon]

If you're a lazy arse you can get front and new OEM balanced driveshafts shipped to your door for under $900.

Sure, if you hate having $700 in your bank account!

 

[danak]

Agree with above.
Once drive shafts are out, you should be able to rotate the uni joints freely in all directions.
If they stop before the uni joint components touch, or they feel stiff or notchy, time to replace them with genuine uni joints, not cheap junk.

When greasing uni joints, you should grease until you see fresh grease come out around all four bearing cups.
Cheap uni joints use rubber seals that push onto the outside of the bearing cup. When greasing cheap ones, once one of the rubber seals pushes off, grease takes path of least resistance, and you won't get grease into all the bearing cups.
Genuine uni joints use an oring contained within the bearing cup. Grease cannot push a seal off, so grease is forced more evenly through the whole joint.

Slip joints, need care to not over fill with grease

Thank you