4Runrfun

ok, i'm stumped by the noise i'm hearing at high speeds. driving down the interstate at 65-70mph is fine until i let up on the gas pedal, it's then that i hear, what i can only explain as something still free wheeeling/spinning. upon acceleration it goes away. i'va had the tranny rebuilt, driveshaft rebalanced, shocks replaced and changed out the wheels. the niose sounds like it's coming from under the truck. i've owned this truck for 1 year and it has always made that noise. what could it be? suggestions?

Tofer

u-joints going out maybe? any vibration?

TC22RE

Sounds like U joints to me. Park on level ground, put it in neutral, (engine off) make sure the parking brake is on, you dont want to get run over. Then check your U joints for play, they really shouldnt have any. Find one that does and you've found your problem.

mochester

yes, u-joints, or maybe your rear end (ring and pinion)

when you let off on the gas but stay in gear, your ring is now pushing on the coast side of your pinion's gears (ie the wheels are now turning the engine, instead of the other way around, where the pinion pushes on the ring gears, in the direction that everything is built to hold up to)

i used to get a strange noise upon letting off on the gas, which turned out to be that my ring and pinion were both totally torn up, just waiting to fail. i ended up breaking every pinion gear off, in half, and the truck still drove. blew my mind when i saw all of the broken teeth sitting at the bottom of the diff...they had all broken off in half, so half of each tooth remained on the pinion to drive the ring.

meswoleshane

Mine does the same thing. Its something in the transfer case. I removed the driveshaft and it still did it. next time your one the interstate let off the gas so it makes the noise and push the 4wd shifter forward like your trying to hold it into 2wd. I can push on mine and the noise will stop, so I think there is something worn or out of adjustment in the transfer case.

traben27

Bumping up an old thread, but this is going on with mine and I've always wondered what it is. I hear the exact same noise and pushing on the shifter makes it go away...Did you ever figure out what was going on with this and how'd you fix it?

toyotc78

ever since i lifted my 91 4runner i am getting that same noise when letting off the gas at seventy miles an hour i put land cruiser front springs in the back and i can't figure this noise out. i dropped the panhard arm and it still does it driveshaft looks ok

rowdy235

about the shifter thing, Is the vehicle body lifted? If so, the shifter may be vibrating on the floor pan, and holding it makes it quit. Take off the boot and check, just a thought.

toyotc78

could it be the angle of the rear pinion. does changing the rear control arms effect the rear pinion angle

Tofer

the more i think about it..... i think mine was doing the same thing before the pinion bearing needed to be replace. check that and check to see if your driveline is still balanced.

kaiberg

I just found this thread while searching for an answer to this question....I have the exact same issue....Does anybody have any ideas on what the noise is and how it is fixed ?....Mine happens at exactly 40 MPH.....pushing on the 4wd lever makes it go away ??

kaiberg

anyone....one more thing to add....I am sure that it is not u joints....because i didi them not too long ago...and because the noise/vibration only starts at 40 mph and then stop as soon as I get below 35 mph and above 45 mph....and how could the shift lever placement affect u joint vibes....I am stumped