Hey. I need some help with my 1996 80 Series with 412,000 miles on it. I've got a loud rattle/grind noise that happens when I let my foot off the accelerator and get into float. If I completely let my foot off the accelerator, the noise does not happen. If I just back off the accelerator a bit, that's when you can hear it. While I am accelerating, no noise.
At highway speeds, the noise is especially pronounced.
Here's what I have done so far:
Thought it was in the transfer case but my mechanic buddy did not, so I replaced the bearings on the rear diff pinion with new seals all around. Pinion depth, backlash, etc all good. Noise did not change at all.
So then we rebuilt the transfer case. The noise really seemed like it was coming right out of there. After that the noise still remains.
Checked all u-joints on the drive shafts. Transmission is shifting fine and the fluid is the right color. I check the diff oils and t-case oil (and top them off when needed) every two weeks.
What am I missing? Has anyone had this issue? What should I try next?
Thanks in advance for your help!
At highway speeds, the noise is especially pronounced.
Here's what I have done so far:
Thought it was in the transfer case but my mechanic buddy did not, so I replaced the bearings on the rear diff pinion with new seals all around. Pinion depth, backlash, etc all good. Noise did not change at all.
So then we rebuilt the transfer case. The noise really seemed like it was coming right out of there. After that the noise still remains.
Checked all u-joints on the drive shafts. Transmission is shifting fine and the fluid is the right color. I check the diff oils and t-case oil (and top them off when needed) every two weeks.
What am I missing? Has anyone had this issue? What should I try next?
Thanks in advance for your help!