ahickman

Done a bit of searching, but ended up more confused and worried than I want to be. I have a 94 Runner 3.0 that has a progressive vibation which starts at about 50 MPH. Enough of a vibration that I have not taken it over 65 MPH. Just replaced both front rotors and then had the tires balanced and alignment done at NAPA. No change in severity of vibration. Here are the symptoms if anyone can suggest what might be the source(s) of vibration:

1. vibration become significant around 50 MPH
2. feel it mostly in the seat and not in the steering wheel
3. pressing on brakes does not increase vibration
4. no rattling heard, just vibration felt
5. taking it out of drive and into neutral has no change in vibration while cruising at 55 MPH
6. tie rods and IFS seem solid when pushed/pulled by hand
7. no unusual wear patterns on tires
8. no leaks in front/rear diff
9. vibration is not felt in transmission selector
10. no increase in vibration when in 4WD high at 40 MPH

lham

U joint or loose wheel maybe

ahickman

Lugs are tight and I didn't feel any flex in the U joints when pushing/pulling them. Any definitive way of checking U joints

ahickman

Anyone?

ScottyC

iTrader: (1)

Slop in the d-shaft slip joint? I would still bet on u-joints.

Is the 4runner lifted at all?

ahickman

No lift, stock everything. Would the slop in the drive shaft slip joint show up as a sudden jerk when going from park to drive as well?

lovetharunner

When did you last have your tires balanced? Same thing happened to me - turned out I just lost a few tire weights to keep it balanced after a day of wheeling.

thook

I'd check the UJ's, Aaron. The only real way to tell that I've learned is to pull the drive shaft down and rotate them. A UJ seizing can feel stiff while the driveline is still in place. Of course, I usually have heard a "clink" when the drivetrain engages, but it may depend how far it's degraded. Slip joints are good to check, too...........as stated.

[N8]

Replace your drive shaft u-joints. It's cheap and not too difficult. I had a major vibration after putting on my 4" SL & new u-joints solved the problem. My guess is the u-joints were bad before the lift & the increased drive shaft angle amplified a barely noticeable vibration.

ahickman

LovetheRunner, the tires were balanced last Friday before taking a small trip. Thought about swapping out the 31's on it for a spare set of radials I had from my truck to see if the vibration dissapates, but got cold as @#$ tonight and threw in the towel. Decided to soak the UJ bolts in PB Blaster over night and break em loose tomorrow to check/replace.

RobD

Easiest way to check U-joints is to remove the rear driveshaft and drive around in 4 hi. No vibration=driveshaft imbalance and/or U-joints. Make sure you put a match mark on the driveshaft flanges where they hook up so you can put the driveshaft back on in exactly the same spot.

thedude42

have you mudded it recently you may have mud caked behind your wheel causing it to be out of balance happened to me alot when i mudded my 2wd 94 runner!

91 4Runner

I'd say the spindle bushing. I'll tell you why - I had the same issues as you, I replaced the upper and lower b-joints, tierod ends and the u-joints. The issue continued and I found that the brass busings in my passangerside spindle was worn.

ahickman

50 MPH in 4 High.....I will give it a shot tonight. Thanks for the suggestion.

ahickman

91_4Runner, how did you guage your spindle bushing? I had my rotors off last week and gave the driveshaft spline a push/pull at that time, but did not see enough play to be alarmed. How much is too much play at the bushing?

thook

Hehe....there's another thread going on about spindle bushings. Mine are shot, i know, but I don't get any vibration at any speed........even with the hubs locked.

As I understand it, the way to tell if the spindle bushings are worn is to check play at the CV shaft going into the back of the hub. In and out play is normal (To a degree. There are specs on that, though). Up and down and all around is not.

One other symptom of bad spindle bushings that seems common....from what I read, though it may not be universal......is a rattling over bumps and a clicking when brakes are applied.

Let me find that thread. Brb........

thook

'Tis right here....complete with a link to a write-up:

https://www.yotatech.com/forums/f116...lay-ok-162143/

abecedarian

two things I didn't see mentioned: bent wheel, out-of-round tire (and likely on the rear)
both could be balanced out, to the extent that it wouldn't show on the balancer, but would be felt in the truck
maybe rotate the tires, one side at a time, and see if you can get the vibration up to the steering wheel... then you'd know at least which wheel was causing the prob.

ahickman

Had the tires and rims looked at again this week. Same fellow that balanced them first time came back and said the (FR) rim was bent a little so he moved it diagonally towards the back. I drove home and noticed a bit of a difference, but still lots of vibation. Pulled off the 31's and put on some smaller radials I had from my 94 truck. Drove around and the vibration was still there...but not as strong. Just saw a link from Clinchguide where he had a similar problem and found that the companion flange was loose. Going out to pull off the driveshaft now and take a look. Fingers crossed.

ahickman

Alright, I am chasing a squirrel around a tree here. After swapping tires, checking U-joints, restaking the nut at the companion flange and lots of tugging and pulling on joints, I still have a definite vibration that sets up at about 56-58 MPH. If I move up to 70 MPH, it smooths out a bit. Put it in neutral at this speed and as it passes down through 60 MPH, the vibration sets in until about 55 MPH. Crazy! This tells me it is not in the driveshaft or transmission, correct? Thought about replacing the front axle shafts since the boots have been shot and have lots of play in them, but these don't spin unless you are in 4WD, correct? Any suggestions? With the vehicle in neutral and coasting, it would have to be in the tires (balanced twice already), in the rear axle/wheels and/or the front wheels. Nothing from the transfer case, transmission or engine, right?