I think there might be something wrong with my rear differential. I rarely go above 70 MPH but there’s no traffic here, and everyone drives hella fast. Like 80+ in the fast lane. My truck is great at 55, I didn’t build it with the intention of going 80. But a few times I’ve been late for work and I’ve gone 75 instead my usual 65-70. And I hear a buzzing from the rear with the windows up and radio off. But only at 75.
I took the top of the back, the tonneau cover, in order to facilitate moving stuff. It’s in storage. I seem to recollect encountering a resonate noise in my bed covering (called bedrug) at certain speeds with the top off from many years past. The only test would be to put the cover back on and see if I can still hear the noise. Simple enough, but it’s really heavy and a huge PITA. Ironically, I want to get rid of it and get a camper shell, which is even heavier and harder to store / move.
But it’s worse, I had 4wheelparts rebuild my front and rear axles with new gear ratios in 2013. My rear end got an electric locker, which after two harness replacements by myself, still works. It also got an LSD – Limited Slip Differential, which never worked right. I should’ve brought it back but I didn’t want to lose my daily driver. The rear diff cover has developed some oil seeps, so I’ve been keeping up on the oil level and it hasn’t lost enough that I need to add any. But it’s possible that the failed LSD clutch components have contaminated the oil and affected the other parts. I was going to take the truck into 4wheelparts today for a diag, but I failed to anticipate the length of the combined auctions.
Last line is title!