Yesterday I put my 4runner in 4wd to go on a dirt road worked ok then started making a sound like grinding gears shifting a 4 speed manual with bad syncronizers. Second time this has happened. Thinking it could be the front actuator. 120,000 miles and I use 4wd every once in a while. Noise is pretty loud and at first I thought it was the front brakes, but only happens when it is put in 4wd. Thanks for your help. Any idea on cost to replace the actuator?

I just found on toyotaowners.com that the previous owner of my truck had to replace his actuator... $2500 later four wheel drive worked again. He didn't experience grinding, it just wouldn't engage. 2005 v6 and it had about 85k on it at the time.

More information. I put the 4runner in 4wd and it grinds until I take it out. The 4wd light is on and it seems to be in 4wd. However, I got under the 4runner and the cv joint on the drivers side is cut in two. The noise only happens in 4wd, shouldn't lt happen all the time if the joints are damaged?

Are you turning sharply while throwing it in 4hi?

CV joints cut in two? What does that mean? I am not positive in what order the actuators do their respective jobs, but I suspect that the front axle actuator will do its thing first, then the front driveshaft will be rotating at the same speed as the rear and engagement can happen easily inside the T-case.

say what?
pics?

and if the joint or shafts are damaged the hub side will still turn when in 2wd, so you may not hear anything.

I only put the truck in 4wd when I am going straight. I even was in my driveway going back and forth slowly and it still sounded like I was grinding gears. Nevada, thanks for your reply, I am not sure what you meant that I would not hear the noise in 2wd. Doesn't the cv joints turn even in 2wd? I am trying to figure out why it only happens in 4wd. When I am moving in 4wd the noise slows down and diminishes to nothing when I turn the dial to 2wd. I am retired and am wondering if I should trade it off, it has 120300 miles and has a lot of rust underneath. The body is in fine shape and it is tight as the day I bought it new.

well, first we need to know what you mean by the axle being cut.


and i was saying that if there is an issue with the axle or joints, depending on where it is, and what exactly the problem is you might not hear it in 2wd. because, the outer joint will be turning with the tire.

but once you put it in 4wd and start spinning the inner part of the axle, it could make noise.


but a pic of the axle would be good.

Is an axle boot cut or ripped?

this is a scary thread

Sorry, my stupid mistake, sometimes I am an idiot! I meant to say the BOOT was cut in half, the axle is OK. I should have read my post closer! I just came back from a 1400 mile trip and the 4Runner seemed OK until yesterday. I couldn't understand the post by Nevada but now it makes sense, he thought the axle was cut in two! In 2wd the truck runs as normal, as soon as you flip the switch to 4HI it sounds like a worn brake pad on a warped rotor. the sound gets faster and faster as the vehicle speed increases. The green 4wd symbol is lit and not blinking. The blinking locked transfer case light is out. When I turn the switch back to 2wd the noise goes away after the green light goes out. It happens every time I put it in 4wd. I am going to have a friend change the axle assembly and see if that helps. I really think something else is wrong, but what? I can't seem to think that a worn CV joint would cause the noise only in 4wd. Thanks guys for your help. I am retired and on a fixed income!

Does anyone know if the half shafts normally spin while in 2wd?

What year is your T4R?
Which boot is cut?

Lift the front on jack stands and spin the wheel by hand in 2wd only. See what kind of noise it makes and if the axle shaft turns. Then put it in 4x4 and neutral and repeat.

You need to fix the boot anyway so doing the axle shaft replacement is the right way to go.

Keep us posted on what you find.

yes.

I am not trying to be rude, but this thread is extremely difficult to follow, but I will try to make a guess here...

First off, I am going to assume you have a V6 as you mention shifting into 4Hi (for future reference it would help to know the Trim, Engine, Year of the vehicle). When you shift the vehicle into 4Hi are you engaging the CDL (Center Differential Lock)?

Can you post a copy of the previous repairs you found? Like a repair order from the dealer or shop? It might help us understand previous repairs done.

~When you say the boot is torn open, is the grease greenish or dark grey?
~Does the vehicle make light growling/grinding noises when turning or driving normally in 2WD? Or is it ONLY in 4WD that you are having this issue?
~Where exactly are you hearing the noise, center of the vehicle, front of the vehicle, ect?

The CV axle could be worn out/damaged and needs to be replaced, the grinding is most noticeable in 4WD because power is being actively applied to the CV axle vs. it just spinning in response to just being pushed along by the rear wheels. You could also have an issue with the ADD not engaging properly and/or damage to the front differential, we need to get some more information and clarity in the matter to properly understand what is going on here.

Thanks again for your replies. The vehicle is a 2004 4Runner Sport V6 with 120300 miles. I have owned the vehicle since new and the ONLY repair was a stuck caliper a year ago. There is no noise driving the vehicle in 2wd even when turning. When you turn the nob for 4wd the noise starts when the truck starts moving and increases in speed with the increase of the vehicles speed. The 4Hi green light is on steady and the lock diff. light is out. I very seldom use the locked center diff. and only in snow or sand.
The grease on the cut boot is a dark grey. The noise is coming from the front of the vehicle, not by the transfer case or rear. The noise is loud and very easy to here. Like I said, the "beats" get faster as the speed increases.