cusportsman

New to Toyotas and bought me a 92 ext. cab 3.0 4x4 5spd last night. Drove it about 60 miles home and went to go somewhere else, got on the interstate and got going about 60-65 and just cruising. Kept hearing this vibration like a subwoofer thumping like a 2 second note with like 3 seconds between each note. Noticed the sound again on the way back to the house. Curious as to what you guys think it might could be.

Thanks

cusportsman

ttt

Anyone have any idea?

A.Wilson013

How loud is it? Any idea what area of the truck it is coming from?

cusportsman

Sounds like it is coming from under the rear of the cab or under the bed.

Not real loud but it is def audible over road noise.

DJ99

If you're sure it's not road noise, I'd get under your truck for a real close inspection of the underside. Since you say it's rhythmic and repeating, I'm thinking there's something going on with a gear in your tranny, transfer or front differential from your given location under the cab or bed. Maybe if you could get the rear up on blocks in a safe manner (in 2WD only!), you could have somebody give her gas and try to find the noise and vibration underneath. It may help to know if the noise happens in both 2WD and 4WD.

Maybe get a buddy to drive while you lay in the bed and listen for location?

Before you go to this trouble, check the tires really well for tread separation (flapping). There is also the possibility of bearings failing, but under the cab? U-Joints?

There is a great possibility that the previous owner knew about this and sold it to you knowing something was wrong. He may even have had it diagnosed and sold it knowing what it would cost to fix, but who knows.

#1Grunt

rear diff and drive shaft maybe, We had an ambulance lose its pinion on interstate and it made a noise similar to that(drive shaft shaking like heck and pulverizing the rear diff housing) any way good luck keep us posted

cusportsman

What I don't get is I drove home about 60 miles on the interstate right after I bought it. Went to the house, then had to go somewhere else. Got back on the interstate and that is when I noticed the sound.

Haven't noticed it when driving around the neighborhood. Tires look fine.

Trying to get my insurance straightened out to get my title and tags before I drive it except for around the house.

buckshot1224

Why do you guys think this is only at high speeds?

cusportsman

We have determined that the sound is coming from the front end somewhere. So I guess that that is some good news that it's not the rear end.

Any ideas what it could be now? There is an ever so slight vibration that you can feel. We also think that a hub may not be disengaging because at least one of the front tires pulls when in 4lo and the hubs free. Could this be the source of my "vibration/noise"

Toyoda22

its easy to check the hubs. just lift a front tire so its just off the ground and engage the hubs, turn the wheel and look to see if the shaft on the other side is turning. it should be. then disengage, spin the tire backwards a little, should hear a click if it disengages. then roll the tire forwards and make sure the shaft isn't spinning this time. takes about 30 seconds

its possibly could be causing a vibration because with the hub spinning the differential without the Tcase in 4wd its not getting properly lubricated. it would have to have been like that for a long time though to cause trouble, because people leave there hubs locked all winter, i dont know why, it wastes gas. maybe go ahead and change the gear oil on the front diff and see how it looks. probably nasty

cusportsman

Duh, I don't know why we didn't think of that. I'll test them and report back my findings.

Thanks

cusportsman

Both front hubs are engaged whether I have them locked or free. CV Axles and drive shaft spins when I spin the tire. Any ideas why they are like this? Could this be the source of my noise/vibration?

Wonder how many mpg I will pick up when this is fixed?

Junkers88

So with the hubs unlocked (free) the CV's still spin if you spin the tire? And as such the driveshaft to the front end spins as well?

I'd say pull the hubs and inspect them for old dried out grease, or no grease, and rebuild them. They might have been pulled by the previous owner and reinstalled wrong. A caveat here is that I've never messed with Toyota hubs so I may be talking out of my ass but I know my old Warns in my Scout II were jacked up and would lock and unlock (no matter where the dial was pointed) until I pulled them and cleaned them up.

Oh and I've never messed with Toy hubs since all of mine have worked so far.

cusportsman

Yes to both of your first questions.

I am afraid that I will have to take them apart, trying to figure out when I will have the time to take them apart and put back together. This is my main transportation and I usually have a problem with working on something and it taking longer than planned.

Junkers88

Man I hear you. My 89 is my only vehicle. From what I've read the hubs are pretty easy to pull and take apart. Do you have a junk yard or a pick-n-pull near you? The one near me sells the hubs for 13$ a set if I pull them myself. It might save you time a headache to find a set in a junk yard, pull em and clean em, and then swap them out for yours. Then you'd have time to work on the junk yard set and gain some knowledge at the same time. Just a thought.