tsam9

Just got my first yota the other day on a trade 94 4runner. i searched the site but couldnt find anything spot on to my problem. there is a semi loud vibration noise coming from under the truck when i let off the gas when going around 25mph or above. kinda sounds like its coming from the rear end but cant really tell. only does it when i let off the gas and when i hit the brakes it goes away also. any help would be great since im new to the yota family

Thanks!

bluewavecaptain

Possibly a bad u-joint?

KBJ

I have a similar vibration - 95 4Runner - although I really only notice it at higher speeds, under throttle no problem, but when I lift from the throttle I get that vibration, and like you when tapping the brakes it stops. Give it some throttle and it stops. It's when coasting that I really notice it. My suspension shop looked closely at the U-joints(and other areas in the suspension) and they do not seem to be the problem.

My wild-ass guess is that it is something in the transfer case area although we haven't researched it further at this point. My truck is a 3.0L autotrans with manual hubs.

FunRunner88

Check the u joints as well as the yoke the joint its self may be fine but the yoke is worn in someway that is what happened to my friends taco. Another big possibility is drive shaft balance may be whack check for dents. And finally make sure all the tires and wheels are balanced you may have lost a weight happens all the time.

KBJ

Yes, pulling the DS and also checking the yoke are next on the list. We've checked and double-checked the wheel balance(and alignment) so we feel pretty confident that is not the problem.

aztoyman

I had a similar problem after I lifted my truck. Sounded like a bad bearing in my T-case or trans but hard to tell for sure. Only while coasting and most noticable over 30 mph or so. REAL LOUD at highway speeds.

Drive line angle was withing limits so I didn't think it was drive line. U-joints good. Actually pulled trans and t-case and tore them down for inspection. No problems.

Stuck a double cardon (CV) joint in rear driveshaft and everything is good.

KBJ

That sounds exactly what I experience with mine. "double cardon CV joint" any particular brand/place you got it from?

aztoyman

I just used the front CV joint from my IFS. I didn't need it after my SAS.

Early ones have more clearance for flexing, newer ones need clearancing. Search on here, Pirate, 4Crawler or Marlin about clearancing CV joints and what years are best.

Then any driveline shop can make a driveshaft for you with the CV. You will have to get some new spring perches so you can rotate your axle so the driveshaft points at your T-case.

Plenty of threads on doing this also.

shacal13

iTrader: (1)

i have a 80 4x4 and my vibration problem was actually the heat shield on the cat. one of the spot welds broke and would vibrate like crazy. just throwing out another option.

aztoyman

Just noticed it's a 95 runner with auto trans. Leafs or coils? Lifted? If it didn't start after a lift, do some more checking. It shouldn't be a driveline angle issue all of a sudden if you're still stock.

Just to be sure it isn't trans or t-case, pull the drain plugs and make sure no metal in oil. Mine is manual trans and t-case. Was clean but sounded like it was going to grenade coasting at higher speeds.

You would think if they were failing enough to generate metal they would make noise all the time but, cover all your bases. Rear diff too. Make sure no major metal present.

Make sure your trans and engine mounts are good. Stock mounts? Poly are strong but suck for noise and vibration.

Axle bearings usually make a rumble sound when they go out and leak at the wheels.

Make sure U-joints are not only not sloppy or loose but, not siezed. Siezed u-joints will make a hell of a vibe. Easy to miss if you just grab and shake to check them. Pull one end of the shaft and make sure they move freely in all directions.

Sperry

Over the years, I have had several vibration problems with my 95 4runner automatic. (235K, all stock)

1) The stake nut on the companion flange needed to be tighted by 1/4 turn. I did this the first time at around 140K miles, then again at 200K. https://www.yotatech.com/forums/f116...-flange-92457/
This totally solved my 50mph vibration.

2) The gear selector bushing in the console will wear out and vibrate. It sounds like a wobbling spring, but when I first noticed it I thought it was from the tranny. I have repacked with grease several times. You can also buy replacement bushings.

3) U joints on the drive shaft. Had one really bad....I checked several times when on the vehicle and could not move or twist, but when I finally removed the driveshaft, I could see/feel the slop from a worn joint. This was a major vibration before I repaired.

4) Un-balanced wheels. I have the factory alloys with 31x10.5's. There is a Toyota TSB that recommend a lug-centric wheel balance with a special adapter. (not hub centric) on a road force machine. I hand the TSB to the Tire center every time I get new treads...just to be sure they do it right. One time I actually had to take the wheels to the dealer to get them straitened out.

All in all it is pretty stable for a 4WD with 240K.

4Crawler

iTrader: (3)

I generally find vibrations while coasting are due to something being loose or having ecess play:
- http://www.4crawler.com/4x4/CheapTri...FixingProblems

Loose pinion or t-case flange, worn slip yoke, etc.

RJR

One other thing to check, especially since it's a new vehicle to you, and you don't know its history. Check the drive shaft to make sure the u.-joint knuckles on opposite ends of the drive shaft are properly aligned with each other. The ends on the shaft should be aligned, not at 90 degrees to each other. Proper alignment is critical for smooth operation, especially at higher drive line angles.

RJR

InternetRoadkill

Vibration noise from the rear while coasting is typically a loose pinion bearing in the rear diff. It needs to be replaced and/or have the preload adjusted.

tsam9

Thanks for the replies I have been real busy the last few days im gonna check these things out I will update with what I find

Thanks!