GorgeRunner

1995 SR5, 3.0VZE, Automatic transmission. In the past few days, the truck has developed a noticeable vibration that started rather suddenly and is definitely getting worse. It is most noticeable when accelerating and is not there, or way less noticeable when off the gas or coasting. Worse at higher speed and RPMs.
Truck is used for daily driving in the snow, no off roading. There were no "bangs or pops", the vibration just started.
I have to crawl under the truck and have a look, but the weather is horrible; snowy and freezing cold, so I want to have a plan when I do get down and snowy.
My first guess would be the u-joints. In my experience, when they go bad, it's relatively quickly. There hasn't been any clanking from the drivetrain, but I'll give it the "emergency brake on/put it in drive" test and pay closer attention to any noise. Maybe it's a rear wheel bearing, but this vibration is developing rather quickly, my experience is that wheel bearings take a longer time to go bad. Then, there is the transmission. I am a manual transmission guy, I don't like the automatic in this truck, I hope it's not that. No burnt fluid, bad shifting or anything like that. I don't think it's wheel balance, this is a "full body" vibration. Engine runs fine, tires are good.
Sound like something anyone has experienced? Any ideas?

justin_4runner

i have a 91 with the same problem, almost a humming vibration at higher speeds, i would still get under and check the drive lines and the front shafts and that, i think my problem is the front half shaft that has a ripped boot and popping when i turn in 4wd.

Ilovemountains

transfer case mount? My 88 3.0 auto 4x4 is doing the same thing, my transfer case mount is broke, I can grab the drive shaft and push the whole thing up, you can see the rubber blocks are totally broke, which Im sure is causing the driveline to be out of alignment under load. I got a Beck Arnley on Amazon for $50 shipped, the part number is Beck Arnley 104-1387. Make sure you buy an Automatic mount, I found out the hard way that the manual mounts do not fit, if this is your issue! It could also be a bad U joint, I bought OEM Matsuba with grease fittings from these guys for under $20 each, made a HUGE difference.

https://www.4wdfactory.com/store/pro...t-U%252dJoints

Ilovemountains

If you had the drive shaft apart for any reason it could be out of phase wich will cause a nasty vibration too, my 82 Trekker had this issue when I bought it.. Take a look at this page for info:

http://www.4x4wire.com/toyota/tech/driveline/

GorgeRunner

The front axles only have a few thousand miles on them, I redid the whole front end not that long ago. New shocks all around and new steering stabilizer. It's more than humming, it's a distinct vibration; the kind of thing that you know something is wrong and you hope it goes away but you know it won't.
I'll have to look at the transmission mount, maybe the motor mounts as well. Didn't think about those.
I did take a quick peek under the truck today. No oil on the rear wheels that would indicate blown wheel seals and bad wheel bearings. I did see a bit of bright silver at the front end of the rear differential, like a bearing race or seal was pulled out, that's troubling because nothing under the truck is shiny anymore.
I'll have to give it a closer look as soon as I can. The weather is awful; snow, freezing rain, mud, I'll have to wait to get at it. All I can do now is worry and try to figure out what's wrong.

GorgeRunner

Got a chance to look underneath; transfer case mount looks good, no sign of rear wheel bearing problems or any rear differential leaking.
Started it up, set the emergency brake, put it in Drive and tapped the gas a few times.
Clank, clank; front U joint clanking away. Not stoked I have to change the U joint, but happy because it was the cheapest part that would cause that kind of problem.