Topic: Need some help with mystery vibration

[David]

83' yota 4x4  1/2 tn  5spd.

I'm really stumped here guys and need some thoughts.
 I've been trying to track down a severe vibration in the drive train on the above truck and have come up blank.
At 45 mph the transmission shakes crazy from side to side, the knob on the stick looks like a bobble head on a washboard road. I have replaced the front engine mounts, tranny/trans mount, both rear wheel bearings and seals, both u-joints on the rear drive shaft, and the rear trans output seal. 

Replacing the trans mount help a small amount but it still shakes hard at about 45mph.
I tried to get movement from the rear input diff shaft but could detect none, the rear output shaft on the trans has some movement but small. Could the rear trans output bearing be bad and trying to move the shaft not show anything? The same for the input shaft on the diff?
I can feel nothing in the go pedal or the steering wheel.

Any help would be great, thank you. Dave

[HogCanyonHopper]

Has your driveline been balanced and straightened? Any suspension modifications?

[David [OP]]

I've never had anything done to the shaft other than replacing u-joints. Might be time to have that checked as well. Suspension is bone stock, no mods.
I'll figure it out eventually, I hope.

[Dingman.]

Make sure the driveline is phased correctly

Good explanation about halfway down
 http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml#Phasing

[David [OP]]

Dingman. That is a great article, thank you. I'll be checking out the rear shaft today. Thank you again.

[Dingman.]

Hopefully thats all it is.    Let us know

[Dingman.]

This is the only non cv toyota driveline we had laying around.   Anyways snapped a picture of it before we retube it so you can have a picture of a toyota driveline phased correctly.  As you can see you want the tube yoke parallel with the slip yoke. 

 

[David [OP]]

Thank you for the photo.
Mine looked the same, both facing up. I went over the drive line and could find nothing in the line of dents or missing weights. Both u-joints look fine, no movement at all.
I did take the slip yoke out and reset it 180 degrees, I'll try it out tomorrow and see if that helps at all. I'm growing more and more suspicious of the rear end, I'm wondering if a ring and pinion could cause the vibration it has over 240,000 miles on it and both the axle bearings were toast.
Dave

[Dingman.]

Ive destroyed so many rear ends and ive never had vibrations that i recall.   Just loud growling sounds almost.

Not ruleing it out, I just dont think thats it.  But i have been wrong before.

[Dingman.]

Actually i have another question.    Has this had this problem since you got it?  Or did it start after some time?

[junya92toy]

Tires balanced? At 45 mph speed only shake, might be a tire balance problem, with a worn mount, i could see it shaking the shifter

[Rockcrawlintoy]

he has new mounts. i would check the output shaft if its bad it will move. mine shook so bad when at around 35-40 mph

[junya92toy]

Yes I know he has new mounts, I just meant that a worn one with a bad tire could cause a lot of movement, and a new mount would help, but with a bad tire, it still would cause some movement as well

[Dingman.]

I dunno ive driven on some pretty unballanced tires and never had vibs like described.

To rule it out see if you can borrow some different ones

[Rocksurfer]

Bad tire
Bad rim
Tire balnace
Hub(s) not unlocking
Driveshaft unbalanced or out of phase or bad
Loose pinion bolts
Loose output shafts
Bad bearings in all of the above

There are a bunch of things that can transmit the vibration through the driveline and make the trans shake including something as simple as the shocks or steering stabilizer.

[David [OP]]

Morning gentlemen. Well nothing has changed, still shaking.
Dingman. "Actually i have another question.  Has this had this problem since you got it?  Or did it start after some time?"
Now that you mention it, I've been chasing this problem for a long time. Over time it has varied from not so bad to terrible, now it's in the terrible stage.
Turned the yoke 180 deg and still shakes. Output shaft has no movement, diff input has not movement.

Everything in the front end is new with the exception of the stabilizer, I replaced the tie rod with a Marlin unit and did not replace the stabilizer. Probably a big mistake, but shook with old stabilizer.  All new shocks, Rancho 5000. New engine, Marlin flywheel, heavy duty 1600 lb clutch kit.
Today I'm checking the front bearings and hubs, all new but I could have made and error and the hubs are locked. Pulled the front driveline to eliminate it from the list or possibles. No change.
Tires were replaced a few months ago with BFG AT 32's, wheels are original 83' SR5 gold slotted style. Could be bad rims but I would think a tire shop would detect that when balancing. Been looking for replacements, stock are too narrow at 7".
I'll check back with an update. Dave

[2manytoys]

I had a bad vib like described that turned out to be a bent rim. The tire shop found it like you mentioned. BUT..........It took three trips to the tire shop before a tech found it. I kept bringing my truck back complaining of the vib/shake.

After the third trip back in a week a manager got involved. The tech had a ton of weights on one tire. They tried to reposition it on the rim and finally said it had to be the rim. They swapped the suspect rim with my spare and it balanced with minimal weight. Shake is gone. It was around 45 -50 mph.

I think Dingman is right about the rear diff. I too had diffs fail as well as axle bearings. No vib at all. Just a bad rumbling and seals leaking.

[Rocksurfer]

So we are talking 100% stock? No, added shackles, add-a-leafs to get rid of sagging springs. I got a bad vibration when I first added my shackles until I re-aligned my front axle, and I had also put new shocks and steering stablizer which did not help. I'm still thinking it's a rim. Check to see if one or more seem to have a lot of added weights for balancing like 2manytoys said that is a good indication of something more than just balancing.

[David [OP]]

Time for an update.

Got it fixed and boy do I feel like an dummy. I checked everything on the truck then pulled the tires and wheel off the front.
I had them balanced a couple of months ago at a small shop and haven't put many miles on them and all on pavement.
Took them to Tire Pros to check for bent wheels. Turns out that they were both way out of balance,(lots of weight on the inside of wheels) wheels were straight and true. Redone the balance and they are great. Now for the back tires, they are shaking as well.

I would have bet they were ok having just had them done, I guess the kid just messed up.
 I really thank you guys for all the advice and help, you're great.

Now on to one of the last items on the truck that has not been replaced or rebuilt, front springs.

[junya92toy]

Winner winner chicken dinner!

[kneedownnate]

Good for you!  I've been chasing an intermitent vibration on my 2wd for about 10 years and have no idea what it is.  Comes and goes, kind of a harmonics thing it seems.

[nisota]

Wanna hear a stupid funny story? ok here it goes. My driveline was bent & wobblin i didnt even know because the truck didnt feel any different not sure how that happend but anyways a sherriff pulled me over & told me my driveline was all over the place under there honestly I could not feel any vibration in the truck itself. so then i drove my wifes car while she drove the yota in front of me & yep it looked horrible i cant believe it didnt just fly off it was so outta whack anyways sorry just wanted to share a yota story.