I just recently bought an 01 SR5. I have always loved the particular body style so I am really glad to have it. The only real concerning thing about it is a particular noise. At slightly above 60 till just below 70, i have a real low rumble sound. The only thing I can try and compare the sound to is that when someone stops next to you at a light with their bass turned way up and you can feel and see the vibrations in your own car. It starts off sort of mild, then peaks at about 65 then gets weaker as you near 70. After 70 it just sort of disappears. The truck has Goodyear Wrangler RT/S tires that are about 80%. They look good and don't appear to cupped or wearing abnormally. I was wondering if they are becoming resonant at that speed and thats what I'm hearing? I can also see vibration in my rearview while this is going on.

Could something in the rear end cause this? An out of balance drive shaft? Bad universal joint?

I think it too low pitched to be a wheel bearing.

Any advice or input is appreciated.

Thanks

it is hard to diagnose sounds with out a video. shoot one up and posted

Incorrect universal joint angle can cause this kind of issue in approximately this speed range. A lift changes the u-joint angle - do you have one? Another cause can be unbalanced drive line. You could make sure your drive shaft is securely bolted up and see if it looks beat up or perhaps some of the balance weights have been knocked off or new balance weights installed.

Buckaroo

agreed. you just bought it so start doing routine maintenance. start with checking tires; condition, balance, etc. sound still present, inspect U joints on driveshaft(s). check rear diff as that can cause noises at certain speeds. change rear diff lube too.

I'm just spit balling here, but it could be that one of the tires is out of round. When I first bought mine, the PO had put a set of used tires on. Around 60MPH I'd get vibrations in the steering wheel (it would smooth out at a higher speed) and be smooth any speed below that. Went to have the tires balanced and found out that one of the tires was out of round.

I bought a new set of tires (Hankook DynaPro) and haven't had a vibration since. This is my first IFS vehicle and have been told that sometimes vibrations means a bad rack. Is yours leaking or anything? I'd have the tires balanced/rotated/checked before anything else though.

No lift.. I will check for damage to the drive shaft in a day or two when I have a chance.

In the process of putting rear brakes on it, i found the clicking. It is definitely
coming from the differential..

2001 4runner SR5 clicking - YouTube

Before I tear into it, is it something that might be fixable or am I going to need a new dif?

Anyone?

I'd drain the old fluid, see if anything funny comes out with the old fluid. Maybe run it through a strainer on the way out. Then pull the diff cover off and check out the insides. Do you have the e-locker?

I am assuming an elocker is a reared where you can lock the the axles together..

Don't have that..just an SR5 rear end..

You're right about the e-locker, it's a button on the dash that you push to lock the rear end. Let us know what comes out of the rear end if you drain it.

Yes Ill drain in the next few days. Maybe it won't hurt anything to keep driving as if this is what causes the noise at 60 to 70mph I described earlier, it was doing it the day i bought it 1000 miles ago.

Thanks for all the help!!

OK, first I don't much about differentials, but from my research, it looks like there are 3 bearings in there. One for the pinion and one on each side (not including the axle bearings). The clicking must be one of the the side bearings because of the number of clicks per rev of the wheel. The noise is there without the drive shaft turning eliminating the pinion bearing.

Now, can I buy and replace just the two outer bearings?
Do I have to have any special tools?
Are there adjustments that are required when/if I replace them?
Will I need to know the gearing when I buy bearings?
How do I know the gearing if so?

I know this is a lot of questions, but I really appreciate guidance and info from all.

Thanks

i had one that did the same thing and i had to have the drive shaft rebalanced and it solved the issue

I would still check the rear wheel bearings. Rear wheel bearings can sound a little different than fronts when they are failing. Being a 2001, I don't believe that the E-locker was an option. Good luck in your search.

Here's a write-up on setting up a Toyota 3rd member. It does require specific tools, and experience is a big asset. Read through this and decide if it's something you want to try.

Toyota Gear Swap Tech