Yup, last weekend had the rear end in the air, took both wheels and brake calipers off to only hear the drive line. Either side felt solid, no back / forth or up and down movement on either side and when I spun it by hand it felt OK.

I am pretty sure I can feel the noise lessen when turning right and def no change in noise when throwing it into neutral.

Diff oil I have replaced recently, however the PO hard to say. The PO is a coworker of mine who had the car since it was brand new, but he is not very mechanically inclined and does not remember if the diff fluid has ever been replaced. I will say when I drained it was black and stank to high heaven, however the fluid level was spot on, when I removed the fill plug a small amount started coming out. I have to assume it was never replaced and has 180K on it. I cannot complain too much though, coworker sold me the 4Runner for $500 so I know I will have to do some fixing.

That's a lot of dough for what is probably a guess. It's not hard to pull the axles slightly, just can be time consuming especially if in the rust belt. I'd look at videos on it and pull enough to check the bearings and such. Or just get a used axle and call it a day.

Luckily this car was purchased new in Texas, and spent all of its life in DFW area, so rust is pretty much nonexistent. I have to educate myself on drum brakes from what I understand those have to come off in order to pull the axle... maybe they do not have to come out all the way just to pull enough to check the axle bearing?

I think you may be able to pull it out an inch or two by pulling the nuts off the back of the plate and maybe pulling the caliper. There's also a tip about slicing a groove in the hose bracket so you can pull the hose out without opening the hydraulic system. Check out some seal replacement videos on YT.

If you don't have to touch the emergency brakes, it will save you a headache. They are a pain to work on but there's some good tips for that too.

Had a chance to do some digging today... basically slid the whole axle out (without taking off the brake assembly or parking brake stuff) just so I can isolate the axle. To my surprise, there was a little bit of gear oil leaking (very small amount as far as I can tell), the dust shield or axle seal, whatever the correct term is, is in pretty bad condition and there was some what looked like reddish grease... I was worried for a second as there was no play in the bearing, but as soon as I started to rotate the dust shield back and forth, as much as the parking brake cable would allow, it felt very gritty and not smooth at all. I am basically convinced the passenger rear wheel/axle bearing is shot.

Now the dilemma... Looks simple enough for a DIY job, however I do not have the bearing pulling adapter for a Toyota or a 20T press that is on a H-frame. I could get both of these for under $300, plus the bearing (I am partial to Koyo) for about $550. Around where I live (Farmersville, TX) I went to a few independent shops and asked them if I brought them the axle shaft and the bearing if they would press the old one out and the new one in, but all said nope, not a Toyota. Anyone know of any mechanics in the Dallas, TX area that will do this job if I bring them the axle? Not sure who much they charge but anything around the mark of buying the tool and press would be a no brainer for me.

Thanks!

Keep calling around. My shop in Cincinnati pressed in my rears for $75 and charged maybe $125 for the bearing for timken on each side. Dallas is a big town and has to have a ton of machine shops.

Consider putting the beveled seal ring on reverse so there's more flat area for the seal to ride on as well. As is, the seal rides very close to the bevel, and it seems it's only to guide a high speed installation at the factory.

Because I left the bevel facing in, despite me telling the shop to flip it I ended up only pressing in my oil seal into the housing 90% and then a little silicone around the outside on one axle because it still seeped a drop or two. Dry now.

With no driveshaft or axles and turning the input on the rear end, you'll know if the diff is bad. Mine sounded and felt like a rock tumbler.

Exactly what mine sounded like. ECGS still makes noise... not impressed with them.

Did you have them intall the solid spacer?

The solid pinion spacers prevent loosening of the gear setup preload. Solid spacer and shims replace the crush sleeve and in theory should eliminate the problem from occurring again.