sr5yota

I recently got a 97 4runner sr5, 3.4v6 it's a 2wd automatic with about 277k on it. First thing I had to do was change plugs and wires due to a couple of plugs that were in pieces and had the truck barely running. Well now she's running like a charm as far as the motor and tranny. When I'm driving down the highway it has a pretty good constant vibration, but as soon as I take my foot off the gas there's a pretty loud metal grinding or clanking noise that will go in and out till I'm almost completely stopped. If I press the gas while its doing it, it immediately stops!! Any help would be much appreciated.

JasonYota

iTrader: (1)

Welcome to Yotatech!
To me it seems like your 4runner might need some u-joints.
Get underneath it and see if there is any slack in the rear driveshaft. Also I would take a look at the transmission mount and drain and refill the rear axle because of the mileage and for maintaince.

sr5yota

Thanks I will definitely try these tomorrow. I did get underneath the truck and yanked on the drive shaft and it was solid no play at all. Haven't checked the tranny mount, to begin with i thought maybe the brakes cause it needs new rotors and pads. But it does it whether I press the brakes or not.

JasonYota

iTrader: (1)

If the drive shaft is good and tight it might be the rear axle it's self. The symptoms you described point out the u-joints, in my experience. It could be gear noise in the rear axle. Any time I buy a vehicle I always check the gear oil weather it's in a transmission or axle because it is often not changed or even checked like it should.

sr5yota

The only thing is the noise sounds like it's coming from the front of the truck or somewhere right under me.

JasonYota

iTrader: (1)

Does it do it at slower speeds like 20mph?
Try and get somebody to drive it past you and pinpoint where it's coming from. It can be hard to tell where a sound is coming from if your driving it and the noise is somewhere underneath.

sr5yota

I can be doing 50 or 60mph and as soon as I let off the gas it will start making the clanking noise. And it will make the noise all the way down to right before I completely stop, granted its not constant the whole time I'm coasting to a stop, it will go in and out but the lower the speed gets the more constant it gets. And pushing the brakes doesn't stop it at all, the only thing that stops it is the accelerator.

JasonYota

iTrader: (1)

Is the sound kinda like a clicking or a constant wine/howling?

sr5yota

No there's no clicking or howling. It's like a metal to metal clanking noise. And it only happens when I let off the gas. As long as I'm accelerating or holding a constant speed it's not there. And then of course there's a vibration that's always there no matter what.

sr5yota

And also if this helps the sound actually somewhat follows the speed of the truck. Like it gets a little slower as I coast and lose speed.

JasonYota

iTrader: (1)

Yea check the u joints on both ends of the driveshaft. I would remove the shaft and see if they move freely on both axis. Also just remembered I had a Tahoe that when I let off the gas to slow down there was a loud bang as if I got rear ended. I had to take the shaft out and clean the splines on the end of the transmission and it fixed it. But that wasn't constant like yours.