FJ62 Driveline rumble.................... (1 Viewer)

[mobydick]

I've been chasing a rear driveline rumble in my FJ62 for awhile. I thought it would be a bad U-joint but replacing both did not solve the problem. The truck has had a 2-3 inch lift for some time now and has an Aussie locker in the original 4.11 gear-set and TC. Any opinions on possible culprits would be appreciated.

 

[too tall]

You should find a road with a slight downhill grade and try doing some acceleration/deceleration tests. See if the problem gets worse under either situation. It is fairly easy to determine the difference between the two when coasting down a long grade. If it is worse on decel than you may need a shim to tip the pinion up. You may need to do the reverse if it gets worse on acceleration. A picture from the side with a wheel removed might help to determine if it is a pinion angle issue. It will help to see the angles if you step away and zoom in with your camera to "compress" the image.(less aspherical distortion)
Sounds to me like a pinion angle issue.

 

[HemiAlex]

Check if you can push around your rear output shaft flange on the transfer case. When I had the same rumble it was due to a huge amount of play in that bearing. Push up and down, avoid rotation because you will feel the lash of the gears.

I had to rebuild the t case to fix it.

 

[mobydick]

^^^ The T-case issue is my biggest fear. Is it possible the slip yoke is worn? I will check these suggestions asap. thanks. The "rumble" is always between 50-60 mph and on level ground with little pressure on the gas pedal. No rumble at all during accel or deceleration. I can stop it by adding gas or braking or downshifting out of D into 3rd. It makes no noise at all above or below the 50-60 mph range.

 

[Michael Hanson]

Hi, Probably torque converter. Or overdrive bands. Mike