Vibration in the rearend

[Kroozer74]

I have a quick question about my 76 FJ40. It has started to get a bad vibration in the rear end when I get going over about 40mph. It starts to feel like it does when you have a bad U-joint but I have checked my U-joints and they seem fine. I am pretty sure that it is my pinion bearing that is going bad, because I pulled my drive shaft off the other day and the pinion nut was lose! Does this sound like a pinion bearing to you guys?

If it is the pinion what all is envloved to replace it?

Pull the axles out, pull the 3rd member and pull the pinion out and have the bearing pressed off?

Thanks

 

[John Smith]

I have a quick question about my 76 FJ40. It has started to get a bad vibration in the rear end when I get going over about 40mph. It starts to feel like it does when you have a bad U-joint but I have checked my U-joints and they seem fine. I am pretty sure that it is my pinion bearing that is going bad, because I pulled my drive shaft off the other day and the pinion nut was lose! Does this sound like a pinion bearing to you guys?

If it is the pinion what all is envloved to replace it?

Pull the axles out, pull the 3rd member and pull the pinion out and have the bearing pressed off?

Thanks

Yes, If the pinion bearing is worn and sloppy you will need to R&R the entire diff and you will want a press.

 

[Kroozer74]

That's what I was thinking because I figured if I already have it torn apart I should go ahead and replace all the bearings and seals too.

 

[Kroozer74]

One more quick question. I have installed a 4" lift on this crusier. Could the lift have effected the drive line angles enough to make this bearing go out or is it probably just from old age?

 

[bakocruiser]

I'm no expert, but if the cruiser didn't vibrate immediately when you installed the lift, then the lift has nothing to do with the problem you have now. I'm facing the same problem now with my '72, although at this time the rearend is on the bottom of the list to fix. Good luck.

 

[1911]

One more quick question. I have installed a 4" lift on this crusier. Could the lift have effected the drive line angles enough to make this bearing go out or is it probably just from old age?

If the operating angles of both u-joints are more than 3-4 degrees different, it's possible to get a vibration at certain speeds without any bearings or u-joints being bad (though this condition will shorten u-joint life). If this is the case, you would usually get the the vibration at one speed but then it would go away when you get faster.