2001 Toyota 4Runner Rear Differential Problem - Anyone Else?

[MarkP0902]

I have a 2001 Toyota 4Runner SR5, and recently my rear end began to be very, very loud. I had the rear differential replaced with a used one from a junk yard because I couldn't afford to spend the dough to get a new one, and now the new one has issues. I hear through the grapevine that this generation 4Runner (2006-2002) has a lot of issues with the rear ends (particularly the rear differentials) going. Has anyone else with this generation (Generation 3) 4Runner had this issue? Is it true that this is a common problem for this model and that they go easier on this car than on others?

I am thinking about having my original rear end rebuilt, but I'm not 100% sure that the new one is bad, I need to have my mechanic check some other things, I just seem to be getting a lot of back pressure that causes vibrations and whining noises when I coast, which is not the same problem I had on my other rear dif, that one was just loud whenever the truck was moving no matter how slow or fast and no matter if I was accelerating or coasting. My mechanic already adjusted a bolt that connects the u-joints and that has reduced the vibrations, but it still makes a lot of noise and some vibration when I coast. Before the adjustment, I could feel the vibrations through the whole truck and even on my foot on the pedal, as if i were driving over a rough old paved road, but now the vibrations are limited to feeling like they come from the rear end. I'm not sure if this "new" used rear end is bad too or if I just need more adjustments down there.

Does anyone have any information about this problem with my model? Any advice?

[robs10]

I have a '99 and had the rear diff. axel bearings/seals go. The mechanic I use said it was typical for this generation. Your problem sounds like it might be more serious or advanced. Possible the oil ran low? As far as the vibration goes, did the mechanic try rotating the driveshaft 180'? I always mark my driveshaft if I pull it just in case it's more balanced better in one position (in relation to the diff. yoke) than the other, but not sure if that makes that much difference. It might be worth having the carrier pulled to inspect the ring gear, spyders and bearings. BTW, how does the gear oil look? It there a lot of metal in it? Does changing the oil affect the vibration?