BEVO76

Curious if anyone has had this problem before. I get a vibration slight grinding noise when I accelerate hard from a dead stop. It does not occur during any other time. My only guess is that the starter needs to be shimmed because its hitting the flywheel. Auto trans shifts fine but the noise sounds like its coming from under the passenger seat.

I know this isn't a lot of info but its kinda hard to discribe the noise. Again only under hard acceleration.

Thanks

toobroketoretire

Its very possible you have a broken transmission mount..................

cagotzmann

Open the hood and do a few quick accelerations, watch the engine level. It should try to lift up from the drivers side. If it moves up ,I would check the engine mount on the drivers side, and also check the transmission mount. But start with the engine mount on the drivers side.

kanvasman

I also think a mount might be broken. If a motor mount is bad, as the engine lifts up it could be causing your fan blades to hit the shroud.

BEVO76

Thanks for the replies guys! I did have an issue with the fan hitting the shroud but that was due to getting the fan powdercoated. After the first 100mi that all went away.

I checked the trans mount this afternoon and it was fine. No cracks in the mount and no breaks.

As far as the motor mounts go they are fine as we just dropped the 383 in 3 weeks ago and they were fine when the engine went in.

The noise is hard to discribe but I will give it another try. I doubt many have heard this....but here it goes. Sometimes when I put my seatbelt on it will spool itself up while im driving and makes a sound I cannot discribe unless you have heard it. Another thing it sounds like is when the exhaust is rubbing on metal and when you mash the gas it makes a buzzing metalic ringing sound. The noise comes from the passenger seat or just behind it.

Yall must think im crazy!!!!!!!

BEVO76

I wonder if it has anything to do with 30 year old rear dif fluid that I need to change out? Probably not but just a thought! Or half shafts and driveshaft u joints that need to be lubed

toddalin

Real common when the rear end of the car sags as the carrier bushing wears. The car goes squat under acceleration and the rear U-joint rubs the tunnel. If you get the car up on a lift, you may see the "witness marks" on the tunnel.

The easy fix is to remove the nut on the carrier, pry the carrier away with a big screwdriver, and insert a couple fender washers in between.

I had these symptoms after installing the Guldstrand aluminum bushings, and this was the problem, and this did fix it.

The better solution may be to replace your bushings.

BEVO76

Brother I think you nailed it there is a distinct line on the rear of the driveshaft im guessing thats what its from huh!

BEVO76

My bushings are shot as well but im saving for a v&b full suspension kit. Explain again where I need to pry up on and place the washers until I get the suspension kit

toddalin

In the picture, bushing "C" has compressed.

You need to remove nut "A," and use a big screwdriver to pry piece "D" away from its mount and push bolt "A" back (or up) enough that you can slip a couple fender washers between bushing "C" and piece "D."

Then reassemble it.

BEVO76

Thanks for the help you were dead on with the noise and the solution. Would I still need to do the washers if I replace the bushing?

toddalin

Probably not.