okie81

I thought it might be driveshaft too. Correct me if im wrong but if it was, wouldn't you get vibrations at other speeds than 55+ mph? The driveline should rotate at a 55 mph rate in another gear right?

Just some group brainstorming...

mickwheeler

The rear driveshaft is coupled to the rear axle... and so turns in direct relation to the rear axle. In other words, the driveshaft rotates at exactly the same rate as the rear axle (based on gearing... 4.10, 4.30, 4.56, etc.). So it makes turns for 55MPH only at 55MPH and turns for 60MPH at 60MPH, etc. The engine and internal transmission gears are the only parts that may turn the same number of RPM's for different speeds (i.e. - 3000RPM for 40MPH in 2nd gear and 3000RPM again for 80MPH in 5th gear).

I'll share my driveline vibration story for your reading pleasure... I had a (very) slight vibration at 65-68MPH and didn't think enough of it to worry. Then I installed a suspension lift, which changed my driveline geometry just a bit... and the vibration got steadily worse and had a wider variance in speed, starting around 45MPH. All of my components seemed to be in good repair (tires, lugs, hubs, brakes, shocks, u-joints, etc.), but I elected to pull the driveshaft and check the u-joints with the shaft out. Sure enough, the rear u-joint was stiff. So I changed it out and it reduced my vibration by nearly half... but as you may have guessed, it didn't completely solve the problem and soon it was back to the same amount of vibration as before.

The solution was both better and worse than I had guessed: I had to have the driveshaft rebuilt. As it turns out, there is a CV-joint inside the double-cardan at the front and it is notoriously failure-prone. The part was $50, the two double-cardan u-joints were $12.50 each and labor was $125, which included removal, rebuild, balance and installation. Grand total: $200.

I'm not saying that I'm positive it's your driveshaft, but if it were a reasonable bet, I'd take it. Call some driveline shops and get some quotes. I got quotes from $150 to $800 for the rebuild (not including parts). I can't heap enough praise on the guys that rebuilt mine because they had to get the CV from a competitor (apparently the 2000 4Runner has a year-specific part, which changed for 2001) and then worked all day on my driveshaft so I could get back on the road. Even if you're convinced it's not the driveshaft, it's worth a trip to have it balanced (around $35) to find out for sure.

I hope my story sheds some light and I hope you get yours solved for less money than I did. If you were in Atlanta, I'd take you to a great shop (father/son operation) and make introductions. Good luck.

Blue_petersen77

My problem is a full truck shaking at almost exactly 60mph and continues until 65mph then smoothes out and gone at any speed above 70mph even at 90mph (engine doesn't want more) it's smooth again.
I have noticed that if I wheel it pretty good on bumpy trails the night before, the next day on the Interstate I don't have any problems or vibration in the morning but it starts up again in the afternoon until I bounce it around some more.
Any ideas?

Maybe she's just trying to tell me she likes it rough lol.

mickwheeler

There's a reason that it feels smoother after wheeling... it's because when you're on pavement, the arc of rotation for the u-joint is very slight and it becomes "settled" into this limited amount of travel. This is also why it's a requirement to index and mark the driveshaft when removing it so that the u-joints will continue to have the exact same limited arc of travel when re-installed.

When you go off-road, the arc of travel is extended due to vertical driveshaft movement when the axle travels further in its range of motion. This serves to force the u-joint past its sticky needle bearings and will make it feel "smooth" until it settles back into the normal arc. And starts to vibrate again.

This is only a guess, because I don't have the benefit of seeing your driveshaft first-hand... but your description of symptoms (vibration 60-65MPH) is exactly how mine started.

Call a few driveline shops and describe the symptoms... I hope their prognosis is more optimistic than mine.

Blue_petersen77

But then over time wouldn't your u-joints wear into the travel of your driveshaft?

mickwheeler

Good question, but the answer is no... If you're talking about strictly off road use. Even if all of your driving were off road, the u-joint would still wear out, just further in its arc of travel. This is precisely the reason for indexing... your u-joints have settled into a limited amount of arc. Regardless of use. Though highway use causes the bearings to wear out at the limits of the u-joint travel exponentially faster than off road use.

Think about the amount of revolutions that the drive shaft makes when traveling on the road or highway as compared to the number of revolutions when off road. Off road use presents much lower speed and much greater vertical axle flex. In this type of use the axle is seldom at the same point of its vertical travel (bumps, rocks, obstacles, etc.), so there is little chance the u-joint is being worn into a single spot in its rotation. So, given the reduced speed (fewer revolutions of the driveshaft), it would take a tremendous amount of off road use (even on relatively flat, level terrain) to produce the same type of wear as would be typical of on road use.

Hopefully this makes sense. Lower speed + greater vertical axle travel + fewer revolutions = less wear on the u-joint.

This is not to say that off road use presents less wear on all parts or that u-joints don't get damaged when off roading... quite the opposite. The torque required by large tires and climbing rocks puts tremendous strain on driveline components. I'm simply trying to illustrate that the type of wear on u-joints (and CV's) when rotated at high speed and at relatively the same point in the axle's vertical travel during on road driving will cause the wear to be at very particular points in the u-joint's (or CV's) rotational arc.

When considering the arc of rotation for the rear u-joint is something less than 3 degrees (depending on the driveline geometry) and considering the driveshaft turns several thousand times per minute at highway speed... the u-joint is "turning" less than 3 degrees in each direction of its arc of travel thousands of times per minute. Good u-joints withstand many thousands of miles with only this limited amount of "turn" and flex.

Hopefully this sheds a bit of light on u-joint wear... Once upon a time, I designed and built mechanical couplers (as an engineer), but that says little for what raw horsepower can do to a driveline... whether over time and miles of highway or trying to turn 37" tires in a creek bed on a set of tired u-joints, bearings and axles.

Blue_petersen77

That's very informative! Thanks! It made me understand the point you made earlier. I'm eventually going to have to look into my drivetrain but I can deal with it for now.
Guess i'm gonna have to lol

mickwheeler

I've been lurking since I bought my 4Runner last year... searching, reading, learning from the mistakes of others and gaining an appreciation for the community. I'm happy to finally contribute.

When it comes to driveline vibrations, always suspect the part that rotates the most and wears out the fastest (typically the driveshaft, u-joints, etc.). As long as there is no reason to suspect the strength of your driveshaft or u-joints and you can put up with the vibration, then let your wallet decide. Just remember that plan only works until it actually breaks... then you get dirty and your wallet gets lighter. Best of luck either way.

mickwheeler

One other note... the guys who run driveshaft shops (typically) have a tremendous amount of experience with driveline issues. A phone call may save you time, money and stress/worry over whether the problem is serious or minor.

gornish_hick

Is it possible the center bearing worn out have this same effect? I've been having the same type of issue had this same vibration between 55mph to 65mph. so i took a look underneath and noticed it was leaking around where the driveshaft joined the diff. so its got me curious if that may be the problem. never the less you make a good point about the driveshaft out of balance, thinking it wouldnt hurt to get that checked out in the process.

mickwheeler

It is certainly possible that a worn bearing can exhibit similar effects... However, the tendency of bearing failure is to have a greater deviation from center in direct proportion to speed. In other words, the greater the rate of rotation, the greater the vibration. There may be a "sweet spot" in the RPM range where there is less vibration, but the rest of the RPM range will be worse as it goes up.

This is the inverse of the effect of an imbalanced shaft, which has several spots in the RPM range which vibrate worse... called critical speeds. These are all harmonics of the worst RPM for vibration (think of musical harmonics, since rotational dynamics are the same principle) and while they may exhibit at 60-65 MPH, the next harmonic may be outside of the performance range for your vehicle to test (say at 140 MPH)... so you would never experience the next higher critical speed for the shaft. Only the first one.

I hope this explanation helps... Though this discussion is all academic until you check the tolerance of the bearing and whether it's within spec. Call a few driveline shops for quotes to check the balance of your driveshaft, it will be much cheaper than the bearing and it's likely they can tell you right away if the vibration is the shaft, bearings or something else entirely.

blake.nemitz

this happend to me in my 4runner. i was running 33x12.5-15 tsl bias plies. the tires in front had a little less tread on them then the ones on the back. this caused a frquency pulse when going 60-70 and increased with speed. the pulses were about 2-3 secconds apart, this was due to the front tires being a little more worn, thus making them just a hair smaller, when the tires rolled down the road fast enough to make some decent noise the front ones were turning a hair faster then the ones on the back, noot by much just by the tiny fraction of height difference , making the road noise pulse, like tuning a guitar string and its real close to the tuning for but not quite, it makes the same frequency vibration because the sound waves from both are very similar but just a little different, making the pulses when the curves of the sound wave line up for a fraction then dont.

pedalquickly

I know this is an old thread but wanted to give my input plus ask for advice. I have an 01 SR5. I have been chasing a pulsating high frequency vibration since I purchased the truck several months ago. The vibration is as many have said, between 60 and 70 mph. I can see the vibrations in my rear view mirror and feel that be cause of the high frequency it is something from the driveshaft out. Just guessing I think the frequency is about what the driveshaft would be turning at that speed.

Things I have done thus far:, Rotated and balanced all the tires, swapped the 3rd member with a different one, replaced all the "U" joints and had the driveshaft balanced at a drive shop. The only thing I haven't done is have the bushing checked in the end of the transmission.

I have some questions? "mickwheeler" posted "As it turns out, there is a CV-joint inside the double-cardan at the front and it is notoriously failure-prone. " Since mine is a two wheel drive, do I have this CV Joint? Is it hidden within the driveshaft?

If there is a problem with the busing in the tail of the transmission, is it something that can be replaced without dropping and dismantling it?

It is my mission to figure this out!!!

Thanks for any information.

YotaWoRx

I had this issue. New tires solved the problem. One might be out of round

mickwheeler

@pedalquickly - This is going to suck (mildly), but my buddy has a 2WD version that was doing the exact same thing (right down to the speed where the critical frequency is reached). He chased all the same things you've chased (tires, drive shaft, etc)... and it turned out to be the bearing/bushing at the output shaft of the tranny. He waited too long to repair it and it very nearly ruined the output shaft and did ruin the yoke on the driven end of the drive shaft. This is simply my best guess, based on the symptoms you've described (and my experience). Good luck.

pedalquickly

I finally figured it out. Even though I had replaced the ujoints and had the drive shaft balanced, I still suspected it. I bought a used one off of the internet for $100 plus shipping ..figured what did I have to lose? IT SOLVED MY PROBLEM no more vibrations!!. The ujoints felt OK, so I installed it without doing anything to it..Now the vibration is gone..Yeeehaaa!!

Mderoncey

I have had this issue on several vehicles of different makes and models. Infiniti G35, Honda Civic, and Mini Cooper. I have been through the drive-lines, brakes, wheels, tires, bearings, etc., to no avail. My 2008 Mini Cooper started this at 32k miles and 6 years of age. Same thing, never found the issue UNTIL the harmonic balancer (flywheel pulley) failed at 58k miles. Replaced the pulley and PROBLEM SOLVED. I hope that this helps at least some of the many folks out there with this irritating issue. The Harmonic balancer is either rubber or oil filled. The rubber can deteriorate from the heat of the engine, often slinging chunks of rubber, or leaking oil long before complete failure.

Samurai_Sam

I had a similar problem, had tires balanced, checked u joints and cv's, motor mounts, the whole deal. Never could figure it out. When it finally came time for new tires, the tech at the shop said he noticed one of my tires was out-of-round. So the tires were balanced, but had a flat spot or potentially broken belt. With the new tires there was zero vibration. Much cheaper to fix than rebuilding a drive shaft that mayou be fine IMO