Whines When Foot Off Accelerator & Clunk Just Before Stop

[jadefox]

Hi, All.

I'm a relatively new T4R owner (of an old 2000 200K+ miles, 4wd auto T4R), and I experienced a new issue yesterday during a long drive that involved stop and go around-town driving and highway miles. When I take my foot off the accelerator now, I hear a whining sound. If I accelerate, the whining sound goes away. As I'm coming to a stop, there is clunk before coming completely to a stop. The two sounds appeared at the same time, so they may be related. Any thoughts? The whine is more noticeable at lower speeds (not at highway speeds). Thanks in advance.

 

[02SE]

Based on your location, the miles on your 4Runner, and your description of the problem, one possibility that immediately comes to mind is a hole in your axle housing due to serious rust.

Rear axle housings on 4Runner's that live their lives in the wet northeast, can rust enough that they start to leak gear oil. Which can quickly mean the complete loss of gear oil. The differential and bearings will in short order make noises similar to those you described, as they are destroyed.

I hope that isn't your problem, but it is one of several possibilities.

 

[jkoni426]

the clunk is probably the drive shafts in need of grease

 

[jadefox]

Based on your location, the miles on your 4Runner, and your description of the problem, one possibility that immediately comes to mind is a hole in your axle housing due to serious rust.

Rear axle housings on 4Runner's that live their lives in the wet northeast, can rust enough that they start to leak gear oil. Which can quickly mean the complete loss of gear oil. The differential and bearings will in short order make noises similar to those you described, as they are destroyed.

I hope that isn't your problem, but it is one of several possibilities.

Thanks! We just (I mean *just*!) replaced the pinion bearings, which were making a noise, but one that was far more subtle than this one. We're not leaking any oil to speak of at this point. I'm going to go have a look again at the axle housing.

 

[jadefox]

the clunk is probably the drive shafts in need of grease

We just greased everything, but I'm going to go back over it. The clunk started at exactly the same time the whine started. Of course that doesn't mean they are related...

 

[02SE]

Thanks! We just (I mean *just*!) replaced the pinion bearings, which were making a noise, but one that was far more subtle than this one. We're not leaking any oil to speak of at this point. I'm going to go have a look again at the axle housing.

Well, knowing that, I'd say the contact pattern between the pinion and ring gear likely wasn't set properly, which could cause the whine you're hearing. Was a new crush sleeve used, and everything torqued to spec.? If not, that could be the cause of your clunk.

If you had complained of just a clunk, lack of greasing the slip-joint in the driveshaft is the most common cause. As mentioned above.

But the whining and clunking showing up simultaneously, would indicate issues with the set-up of the ring and pinion gears. Especially since the diff was just worked on.

I'd suggest pulling the 3rd member, and checking it out.