Vibration starts at 40mph stops at 65mph

I have an annoying vibration that seems to be coming from the front of my 1997 Tacoma 4x4 5spd. I have brand new highway tires and have had them balanced and aligned multiple times.

Symptoms:
-Starts at around 40mph and stops at 65mph
-Is worse at cruising speed and not as bad while accelerating
-Stops if in gear and decelerating
-Noticed that if I am out of gear coasting and push softly on the stickshift as if pushing it into gear, but not actually putting it into gear, it goes away.

There is also and clunking noise if I don't shift extremely smoothly and there has been a squeal as if the brakes are done starting from stopped. (Just replaced them)

From my own research it seems likely that there is a problem with the drive train (U joints?) or possibly the mounts have loosened.

Does anyone have any idea what could be wrong or how I can diagnose the problem?

Thanks
-Ian

 

Have you gotten under the truck to inspect? Leave in gear with truck parked. Emergency brake engaged. See if driveshaft has play in it by trying to spin by hand.Might see problem. Have you greased your u joints?

 

The proper and only way to test for bad universal joints is with the driveshaft removed . You cant tell if the universal joints are seized or tight spots with the driveshaft on the truck . You may see play in the universal joints , but you wont be able to properly check the u-joints without removing the driveshaft .All it takes to create a vibration is one seized universal cup and there are 4 cups within each joint .
With this said , you cant tell if that cup is seized with the driveshaft connected .
Removing the driveshaft and manipulate each universal joint by hand from side to side feeling for tight spots as you go
If you beleive its bad motor mounts or transmission mounts , grab a big pry bar and pry at the mounts to see if the rubber is torn or weak .

 

Sounds like the carrier bearing. Mine had very similar symptoms. There is a write up on here about changing it.
http://www.tacomaworld.com/forum/1st-gen-tacomas/260283-how-replacing-carrier-bearing-new-post.html

 

Didn't know there was only one way to check universal joints! Few years back I had the clunk sound as op described. Got under truck and tried to move drive shaft, had a ton of play. Outcome was bad u-joints in rear. Huh, guess it was my imagination. Guess I better stick to carpentry because I must not be doing other things properly. Just saying, there's more than one way to skin a cat!

 

Was there a triggering event? For example I got my wheels rotated & balanced then it developed a vibration really bad at about 65-70mph. I took it back and they had to do a "harmonic balance" on the tires. Drives smooth now.

 

I wasnt calling you out Andy . Guys get owned by u joints every day on this site . I am simply trying to get the word out on how to properly check them .
Yes , If there is all kinds of play in the universal joint , you can tell its bad just by looking at the driveshaft

 

Sorry man. I know you got serious skills. Kinda let my ego get in the way. Just came from a sale post that fired me up a little. All good with me and you for sure. Apologies.

 

^This! Joints should be loose, but not sloppy.

One cup was shot on my rear DS. You couldn't tell by rotating by hand, with it on the truck.
8 bolts, with a 14mm head. A wrench and a socket, jack and stands, and 30 min will get it checked.

A ball joint press can be rented from autozone to do the ujoints. It makes the job almost painless. Just make sure you don't pinch a needle bearing

 

Neverending huh.haha.lol