driving to northern kentucky this evening i heard a weird noise coming from the rear end of my 97 4Runner. It is continuous and sounds like it is coming from the axle. it is making the same sound as if you were inflating a large truck tire. (like how you can hear the air filling up inside the tire) i thought it may have been wheel bearing but when i move the wheel i dont hear anything... any thoughts?

 

Check your rear diff fluid level/condition.
When was the last time you had it changed?

 

How miles do you have on the truck?

 

Drive your rig for a bit and CAREFULLY feel around for something that is VERY HOT. My best guess about sounds like these is metal on metal contact which will generate a lot of heat.

 

i have 145k on this vehicle. i have owned it since beginning of february this year. i have yet to swap the fluid in the rear diff.

 

Make sure you have your drive shaft lubed properly as well.

 

this is what happened to me.

Sounds like your problem.

I didnt have enough grease in the zerk fitting on the driveshaft slip joint...although I had always added grease to it whenever I was doing the uv joints and such.

Apparently it just takes a crap load of the stuff and it is easy to under lube it.

 

thanks... so far i have come to the conclusion that it is def coming from the rear axle... i will however lube the u joints just to be on the safe side. thanks

 

yeah, it was the slip joint on the driveshaft itself.

also, of course, you are aware of the common problem with the rear axle seals going on these...

 

the axle seals are already gone... my brake drums look like they have been caked with grease and oil.

 

At 145K i would put my money on the rear needing to be rebuilt.

Jack it up--put it on heavey duty jack stands and put it in gear--listen to the rear end with a hose or something and see if that is where the sound is coming from.

A bad diff will transmitt its noises all the way to the tranny--making it hard to nail down where it is coming from

 

went to autozone just seconds ago to get some rear diff oil and they do not carry and 90w... wtf? then when i asked the gentleman where i could obtain this type of oil he had no idea nor did anyone in the store.... any suggestions?

 

i plan on doing a rebuild this summer. i already have to replace both inner and outer axle seals on both sides....looks like some one pasted grease and oil in my rear drums... i will be replacing wheel cylinders along with all new drums, shoes, and hardware with the seals. i will however jack it up this weekend and try and figure out what is going on... thanks

 

Thats because most of the folks that work at autozone are retards--its a growing trend in parts houses across America.....and funny because i dont see how they havent been sued for not meeting OEM spec on parts??

IT USED TO BE--guys in the parts houses were retired wrench turners and knew a thang or two about a thang or two----.......