1992 4Runner 2WD
292,000 miles
Automatic Transmission

I've developed a vibration or rumbling sound that begins as I reach 60mph, increases in intensity from that point up until 75mph, and then calms down but still continues to send a vibration/rumble throughout the car. Its not something I feel at the steering wheel, nor does it affect the handling of the car. If I let off the gas, the sound/vibration goes away. Only when I re-apply the gas does it come back at the points I mentioned earlier.

I've begin to examine my u-joints on the drive shaft and cant see anything unusual. There's no play when I try to shake the shaft side to side.

Anybody have an idea of which direction to go next in diagnosing this issue?
Or maybe someone can chime in from personal experience?

Any help is greatly appreciated.

 

Just replaced the fluid in the differential thinking it might help, took the runner for a quick spin, and paid closer attention to the problem.

- Vibrating like before, but I can feel it in the steering wheel.
- Tried tightening the lugs, but they're all torqued down.

After parking the car, I put the front up on jack stands to check out the front wheels.

- Grabbed the left wheel and 2 and 7 o clock, wheel has a bit of play when i shake it.
- The steering stabilizer also moves as if its loose.
- Upper and lower ball joint appear fine, no grease leaks and boots have no tears.

Does it sound like an issue with the idler or pitman arm?
Wheel bearing possibly?
Is there some other method to test out where my problem lurks?

 

Check front tires for cupping and feathering. A belt could have broken on tire or the wheel weights could have come off. Check steering wheel play. Worm gear going out. Or front end alignment problem. Have you checked all bushings?

 

There's a little feathering on the front tires but had an alignment to resolve that issue.
If it were a bushing failure, wouldn't I have unstable steering, especially at highway speeds? The front sway bar bushings may look a little tired but they are still intact. Otherwise everything checks out fine.

Any fullproof way of checking the condition of the wheel bearings?

 

Raise the vehicle and grab the wheel at 12 and 6. try and wobble the tire up and down. If it feels sloppy it needs bearings. If a light click is felt it is okay. You can also grab the wheel at 3 and 9 and wobble side to side. If any slop is felt then it is your tie rods.

Also, it matters which bushing fails and how much. Ex: You may have more play in steering if the idler arm bushing fails. As for unstable steering, no not all failed bushings cause unstable steering. Some failed bushings will cause out of alignments. Just be very thorough when checking underneath.

 

@ 12 and 6 o clock = No wobble, everything seems tight

@ 3 and 9 0 clock = There's slop...I also notice the steering stabilizer bracket shifting back and forth. I currently have a Rancho Stabilizer kit installed.

 

been in for the recall?

Make: TOYOTA
Model: 4RUNNER
Model Year: 1992
Manufacturer: TOYOTA MOTOR NORTH AMERICA, INC.
Mfr's Report Date: SEP 06, 2005
NHTSA CAMPAIGN ID Number: 05V389000
NHTSA Action Number: N/A
Component: STEERING:LINKAGES:ROD:RELAY:CONNECTING
Summary:
ON CERTAIN PICKUP TRUCKS AND SPORT UTILITY VEHICLES, IF THE STEERING WHEEL IS REPEATEDLY TURNED UNDER CERTAIN CONDITIONS WHERE HIGH STEERING EFFORT AND POWER ASSIST ARE REQUIRED, FOR INSTANCE, WHEN FULLY TURNING THE WHEEL WHILE THE VEHICLE IS STOPPED, A FATIGUE CRACK MAY DEVELOP IN THE STEERING RELAY ROD.
Consequence:
IF THE VEHICLE IS CONTINUED TO BE OPERATED IN THIS CONDITION, THE RELAY ROD MAY FRACTURE, INCREASING THE RISK OF A CRASH.
Remedy:
DEALERS WILL REPLACE THE STEERING RELAY ROD. THE RECALL BEGAN OCTOBER 5, 2005. OWNERS MAY CONTACT TOYOTA AT 1-800-331-4331.
Notes:
TOYOTA RECALL NO. SSC 50N. CUSTOMERS MAY ALSO CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY 1-800-424-9153), OR GO TO HTTP://WWW.SAFERCAR.GOV.

 

From the sound of it, you really need new stabilizer bushings. Check the tie rods of course. Feathering is caused by toe usually. Feathered wear inside tire means toe out, outside tire toe in. Loose components can cause rumbling.

Try balancing tires too for the vibration. Maybe you threw a weight.

 

No, have not been in for this recall.

I just went out to the garage to inspect the relay rod and there's no apparent fractures. Would one be noticeable?

Wouldn't an issue like this cause my steering wheel to pull left or right randomly as opposed to producing a rumbling sound from 60-75mph?

 

Would loose components cause this rumble at specific speeds or gradually increase with traveling speed?

 

Have you tried balancing the tires yet? What size tires are you using?

 

31x10.5x15

I'll try rotating the tires first and see if that changes anything first.

 

Rotated Tire from front to rear....about to test and see if it solved my issue..

 

front to rear how?
rears forward and fronts crossed to back?
or drivers front to pass. rear and pass. rear to drivers front and vice versa with other side

 

could be a bearing

 

pull the driveline. the universal could be fused in one direction. you won't be able to tell unless you pull it. i've seen it before and just went through the same thing with my wifes landcruiser. well worth the try.

 

I think you are all way out in left field. It has to be the front driveshaft.

Just a thought but have you checked your motor mounts? Is the vibration specific to a speed or an engine rpm?

 

Rearward Cross. Rears forward, front right to rear left and front left to rear right.

 

Seems easy enough, since the car is still on stands. Guess i'll drain and fill the trans fluid too while i'm at it.

Are the front and rear spiders different or is there only one part for both front and rear?

 

The vibration is very specific. It's the most prominent at 65 mph, tapers off and almost gone past 70 mph. This is the only time this vibration is present. I can drive at city speeds and the problem would not be present. When in the cabin, it sounds like a cell phone is constantly vibrating on a table or desk...Just 10 times louder.

Have not thought about motor mounts, as I never knew worn mounts would cause a constant vibration like the one i'm experiencing.