[jon_7248]

Now this is going to sound weird. For about a month maybe I have been hearing this sound while im on the highway. I have an Xcab so I can lean the seat back to try to find where it's comming from. It sounds like it's from the middle of the truck, maybe slightly to the driverside. But here is the deal. It sounds like a sizzling sound and only happens when I go over 50mpg and cruising. If I accelerate, it goes away and when I dont use the throttle at all it's gone too.

I cant figure out for the life of me what it is! I thought it was just something flapping in the wind like some tape or something, but it's deffinatly related to the throttle, and only at cruise... in other words just barly giving gas at all!


Any ideas????

 

[sqwirlytaco]

could it be coolant leaking and hitting a hot manifold? I had this happen in my 90 4runner cuz some hose on the back of the engine was not properly connected when the shop replaced it.

 

[jon_7248]

Dont think so. One, my collant level is fine. And two, it's comming from under the back of the Xcab part, where the people in the back would be sitting.

 

[STBear]

I have something like this too. It starts around 50 mph but doesn't go away. It seems to be coming from the headliner. At first I thought it was the window seals but if I push against the headlner it stops but returns when I take my hand away.

 

[scottnmos]

Now this is going to sound weird. For about a month maybe I have been hearing this sound while im on the highway. I have an Xcab so I can lean the seat back to try to find where it's comming from. It sounds like it's from the middle of the truck, maybe slightly to the driverside. But here is the deal. It sounds like a sizzling sound and only happens when I go over 50mpg and cruising. If I accelerate, it goes away and when I dont use the throttle at all it's gone too.

I cant figure out for the life of me what it is! I thought it was just something flapping in the wind like some tape or something, but it's deffinatly related to the throttle, and only at cruise... in other words just barly giving gas at all!


Any ideas????

Check your carrier bearing, it could be going bad or just need lube. Sounds like something that happened to me.

 

[Live4yotas]

Kinda sounds like a exhaust problem to me like a broke muffler or a exhaust maniflod leak. I don't know man I have a broke muffler right now this will be my 3rd one and a exhaust leak at the manifold and it makes weird noises.

 

[jon_7248]

Where is the carrier bearing?

 

[jon_7248]

Dont think it's an exhaust problem either. I have had exhaust problems before on my old 4runner and you can tell when your exhaust is broke while the truck is in the driveway. This sound doesnt exist in the driveway. It's like a vibration effect at high speeds which would be why I only can hear it about 50ish mpg. Someone else has the same issue and found it to be their headliner. If it helps, it's like an old window seal that doesnt seal right, or a window is slightly a crack. Not like an exhaust.

 

[mudferret]

Where is the carrier bearing?

It's where the two halves of your rear driveshaft meet. A bracket and bearing assembly attaching to the frame.

 

[Live4yotas]

Yeah I found out all about driveshaft problems I was heading down the interstate doing right at 75 mph and the rear u joint went out and caused the drive shaft to come loose from the rearend it slung and hit the gas tank gaurd thank god for it. I was in my 83 yota 4x4 with over 300k. Anyway when it slung around it sheared all four bolts holding it to the trans and flew out of the truck and smacked the wall on the interstate. I was in the fast line and it slung to the left. I pulled over I thought it was a blow out. What it was when it slung out I ran over it. Anyway I got locked the hubs in put it in 4hi and back down the interstate and found the driveshaft through it in the truck after replace the u joint on the beat up driveshaft and through it back in. If you have any doubt its u joints replace them. That experience scared the shit out of me.

 

[tacd44]

I agree, check the carrier bearing. It's a double u-joint in the middle of the driveshaft. It's supported by a frame cross-member.

If you're not sure what to do, take to a dealer/shop and have it checked. If it failes, it can prepel the driveshaft like a missle.

 

[jon_7248]

Ahh not used to the new type of rear driveshafts...used to one peice.

Hmm, now the thing that amazing me is that if it needs lube, the dealer should be greasing it during oil changes. I remember the dealer doing it on my old 4runner all the time and they where great about it. But I dont live in san antonio anymore. The rule still applies that they grease all the zirks underneath during oil changes right? The dealer in san antonio was telling me that something they do on all the trucks/suvs during oil changes. But I never get a car wash like I do up here so I guess I have to sacrifice something

 

[BajaTaco]

Check your carrier bearing, it could be going bad or just need lube. Sounds like something that happened to me.

Speaking of the carrier bearing, it has that rubber "donut" bushing around it. Any idea how much play is supposed to be in that? There is a ton of play in mine - but the bearing spins fine and doesn't make any noise.

 

[JLtaco]

Speaking of the carrier bearing, it has that rubber "donut" bushing around it. Any idea how much play is supposed to be in that? There is a ton of play in mine - but the bearing spins fine and doesn't make any noise.

I'm wondering the same thing; my carrier bearing has a ton of play as well. I sometimes get a "ding" noise coming from that area while accelerating or decelerating; it sounds like someone is tapping my drive shaft with a wrench.

 

[scottnmos]

Speaking of the carrier bearing, it has that rubber "donut" bushing around it. Any idea how much play is supposed to be in that? There is a ton of play in mine - but the bearing spins fine and doesn't make any noise.

It it supposed to be a little squishy, but if you look at it, it should not have any deformation. If it isnt cracked, or saggy, or ripped, I would leave it alone.

 

[scottnmos]

It's where the two halves of your rear driveshaft meet. A bracket and bearing assembly attaching to the frame.

Beat me to it.....

 

[Eztrog88]

Same thing happening to me, except mine goes for about half an hour to and hour after I stop. Turns out it was really wuite simple; water under the bed liner leakin down and hittin the exhaust pipe. Its not too loud and not anything serious (not even any rust in the bed) so I left it alone.

 

[sjvicker]

damn punks and their zip ties on the drive shaft. I have no idea what your problem could be, just know that it would be fun to mess with someone's head by using zip ties.

 

[scottnmos]

I'm wondering the same thing; my carrier bearing has a ton of play as well. I sometimes get a "ding" noise coming from that area while accelerating or decelerating; it sounds like someone is tapping my drive shaft with a wrench.

I think that if youre getting a ding, that is bad. Tells me that the "donut" is worn out and the driveshaft is hitting the bearing support. It shouldnt be too much to replace, especially if you do it yourself (which should be easy). I would do that soon, seeing as how too much banging would possibly throw your driveshaft out of balance, then itll really get annoying.

 

[JLtaco]

Thanks for the advice. How long does this job typically take to complete?