Chasing a Highway Speed Vibration Problem

Alright, i've developed a problem with vibration, and I cant figure out how to fix it.

Heres what i've done.

• 3" suspension lift (pucks)
• AAL in rear
• Diff Drop
• Suspension components re-torqued
• Passenger rear axle bearing replaced (leaked)
• Fluids changed/maintained meticulously
• Tires aligned (printout showed green across board)
• Tires Road Force balance, and rotated every 5k miles
• Tried pressures from 26-34, attempting to isolate problem, no help
• Changed Front/Rear diff Fluids to Amsoil Severe gear
  $28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)
  75w-90
• Changed Xfer case fluid to Amsoil Severe gear 75w-90
• Flushed transmission fluid
• Replaced inner and outer tie rods (Moog)
• Replaced upper and lower ball joints (moog)
• Rebuilt CV axles (toyota boot kits, with OEM half axles)
• New Rack and Pinnion
• Energy Suspension Rack Bushings
• Replaced worn Carrier bearing (indexed splines exactly as before)
• Greased all Zerk fittings, with Lucas Red-N-Tacky
• Tried a CB drop kit
• And finally...
• Tried a Tom Woods 1 Piece drive shaft...

Still vibrates/wobbles like a bastard at highway speed.
Before the TW shaft, it hovered at ~70mph for vibration to start
With TW shaft, vibration moved to ~75Mph.

I've tried anything and everything to make this damn thing go away. Nothing has worked.

PROBLEM: Horrible side-to-side vibration at highway speeds. 70-75MPH. Shakes violently enough to see rear end vibrate in side mirrors. Now vibration is so bad, side view mirrors are a shakey blurred mess. Shaking feels centered in vehicle. No shaking feeling in steering wheel. Vehicle does not pull in any direction. Front End Tires have minor feathering, noted at each rotation and balance. I've noted that the 4wd shifter stick shakes/vibrates too. Obviously a rotating assembly causing problems.


VEHICLE: 2000 Toyota Tacoma. Access Cab. TRD off-road. Automatic Transmission, 5vz-fe 6cyl engine. 140K miles.



I'm out of Ideas here guys. I need some help. I love this truck, but i'm about ready to light it on fire. Maybe bad bearing in the transmission? bad Third member bearing? Bent axle shaft?

The common fix of a Tom Woods Driveshaft, did not help. ):

I need help. Thanks

EDIT: Mega -update with all changes and final fix.


Since I OP'd this thread, I've changed:
rear-transmission mount
U-joints
Carrier Bearing
Installed 2* Axle Shims
Replaced Rear axle seals and bearings

And the coupe-de-grace, was the re-balancing of the driveshaft.

The rear axle bearing went to crap. Possibly because of the horrible shake. When it finally went, it siezed up my rear brake drum, because the fluid rushed past the seals onto the drum and adjustment hardware, thereby tricking the braking mechanism to think its constantly out of adjustment and letting the star adjustment nut adjust further and further, tightening up the drum to the point of siezure.

The tranny mount and Carrier Bearing went bad, the U-joints had play, and the operating angle at the rear diff flange was 6* (11* down from Double Cardan, to 5* up on rear diff flange.) 2* axle shims were made and installed, and brought my operating angle to 2.5* (somehow 6-2=2.5, Not entirely sure why driveline math is retarded like that)

The final piece of the puzzle was the driveline. I assumed that the local (and reputable) 4x4 off-road shop wouldnt screw up re-assembly after a CB change, but they did, so it was out of phase. I went to another shop and the weights were removed and re-welded, and the shaft ran true with no run-out. A new coat of paint on the shaft, and voila, it is done.

So there we go. Its finally fixed. No more horrid shake. It rides like glass now.



Lessons Learned:

~Even if you assume the shaft is balanced, it might not be.
~Never assume a "prestigious" 4x4 shop knows what the hell they are doing.
~A rear-axle seal and bearing going bad, is always gonna be expensive, but trust that *A Good* toyota dealership will replace them correctly and not fubar it, unlike a automotive repair national chain...

 

I've narrowed it down to RPM.

Exactly at 2250rpm, it shakes. What the hell?

It sticks at 2250 , until I let off gas, and it changes gearing.


I'm seriously beginning to thing it's transmission related.

 

Check your mounts might have broke one?

 

Did this just appear one day? I'm assuming you've had the lift on for some time? Any changes made to the vehicle around the time the vibration started?

 

I'm leaning trans or motor mount.


Only because someone said mount though....

 

Im thinking it may be a mount. I drove for a good 50 miles today, playing around with it more. It is RPM specific.

2250 RPM, in overdrive, causes the shake.

Where are all the mounts located?

 

Also, some weird phenomenon has occurred.

The shake was exceedingly hard to duplicate yesterday . The weather was also 20* cooler than a week or two ago. I also had the cabin heat turned on.

This is beginning to make less and less sense as it progresses.

 

I have a '01 DoubleCab...same friggen problem. I thought it was tires but they have balanced out correctly. I replaced front and rear shocks...did not fix it. I do know I have some play in my center bearing and my rear springs are flat. I have been shopping around for leafs, feeling confident that my problem would go away after replacing leafs and CB, but after reading everything you have done to yours and you still have the problem, I am feeling kind of dejected. I do have some vibration in the steering wheel as well as in the back. Very frustrating.

 

Check the motor and trans mounts said it above and am curious if one maybe broken

 

I had a similar proablem turned out the tire shop bent my rim ever so slightly. At 70-75 it would start shaking so I could go slower than 70 or faster than 80 to get past the shake.

 

I put my truck on a lift, and poked around underneath.

I played around with the rear diff. I noticed I could get about a 1/6 turn left or right, before the tire would turn (in neutral, no e-brake). Evidently this is common, and no cause for concern. I placed a dial indicator on the rear diff mating flange, and rotated it. No appreciable run-out.
I spun the wheels, and didn't find anything out of balance. I shook and tried to jerk everything. Nothing.

I can't check the rear axle bearings, because those shits are buried deep inside the rear axle. Checking those is a full commitment to replacing them, along with all the seals.

I pushed around on the engine and auto-tranny. I didn't get any appreciable movement from the engine, which makes sense, because engine mounts would cause shaking in the front end.

The tranny mount, however, had some movement. I had a few auto technician friends overseeing what I was doing. They agreed the mount is bad. To me, it looks fine. To them, they pointed out a couple hairline cracks in the rubber, along with the (what I thought was minor) vertical movement.

So I guess I'm going to shitcan the tranny mount, and replace it. Maybe this is the ticket?

Stay tuned. I'll be updating this thread as time and changes occur.

 

I had a similar situation with my '11, in which the prior owner had installed a one piece driveshaft. At about 80 mph, it felt like the starship was going to self destruct. It turned out that the driveshaft (not a Tom Woods) was poorly built and way out of balance. A shop that knew what they were doing rebalanced it at 3500 rpm and the high speed vibe is gone. Tom Woods is supposed to be a quality product, but the driveshaft still sounds like a prime suspect.

A couple additional thoughts:

If you have access to a go pro camera, mount it on the frame and see if you can see the vibration.

What is the diameter of the driveshaft? It should be about 3" or 3.5". A bigger diameter is better for not vibrating.

Have you picked up any dents in the driveshaft? Dents can throw off the balance of the shaft at high rpm. Your driveshaft is spinning about 3000 rpm when your engine is at 2250.

Is the pinion flange to driveshaft angle approximately equal to the transfer case to driveshaft angle? They should be as close to equal as possible, so the pinion and tc output shaft are parallel.

The vibration could have caused the tranny mount to fail. My driveshaft caused my pinion seal to fail.

Good luck.

 

Thanks for the update I have had something along the same line as you happening so guess while I'm messing around with my suspension il take a look at my mounts aswell.

 

I forgot one other fairly easy step. Take the driveshaft out, and drive in front wheel drive and see what happens. Just go easy on the gas. (The front driveshaft is not as strong as the rear. But I drove all over town for a few days in fwd, with no issues.)

 

I don't think he will be doing highway speeds using 4x to test that out^^^

 

Similiar issue just ordered lbjs and inner +outer rods already did carrier bearing.

seems to be the same for me as well.

I am wondering if its a issue in the tranny of rear suspension if youve done most of that and no results.

 

The front drivetrain is designed to handle approximately half of the torque/power that the rear drivetrain is designed for. Go easy on the gas, and there shouldn't be any problem. I only drove a few days in fwd, but at speeds up to 80-85 mph. No issues. I wouldn't want to do that long term, but short term it should be ok. If you check around TW, there are guys that have driven for several months in fwd. Also, driving in fwd without the driveshaft was perfectly vibration free, thereby isolating the driveshaft as the source of my problem.

 

Interesting, I may try that. I'm worried about getting up to highway speeds (70-80), with only front wheel drive though.

 

I have a sneaking feeling this may be causing some of it. I'll post results after I drive on the highway tomorrow.

 

I was correct. The piece of crap rear transmission mount was the culprit.

It cost me 100 and change from the dealership, but it killed almost all of the rear end vibration. I'm going to have my local shop adjust the rear angles a bit, but the rear tranny mount was causing a lot of the shake. It is 150K and 13 years old , so it makes sense.

I'll update when I have the angles adjusted a bit. I'm gonna kill this vibration crap once and for all.