Vibration during acceleration

[Stan E.]

Re: Vibration during acceleration

I'd check engine/trans mounts and wheel balance/lost weights.

[Stan E.]

Re: Vibration during acceleration

I'd check engine/trans mounts and wheel balance/lost weights.

[Gerard F.]

Check your motor mounts

as stan suggested above. That was my first thought in reading your original post.

Jerry Fuccillo
#42179

[Gerard F.]

Check your motor mounts

as stan suggested above. That was my first thought in reading your original post.

Jerry Fuccillo
#42179

[Wayne W.]

Re: Check your motor mounts

Check rear wheel alignment. They will do this when the camber is negative and or the spring is low. Causes the u-joints to vibrate under load when it squats.

[Wayne W.]

Re: Check your motor mounts

Check rear wheel alignment. They will do this when the camber is negative and or the spring is low. Causes the u-joints to vibrate under load when it squats.

[Christopher R.]

Re: Vibration during acceleration

If you're going to be under there anyway, and if you're going to take out the driveshaft anyway, mark it, and when you put it back in, put it in 180 degrees off from what it was originally. Might help. Can't hurt.

[Paul O.]

Re: Vibration during acceleration

Tim had a problem similar to this check the clearance between the bottom of your floor and trans cross member the floor can weaken with age and most of us are not as slim as we once were. My floor would contact the cross member under accel or if I would move very far forward in the seat causing a vibration felt in the seat and would be more noticeable in hot weather. Paul

[Timothy B.]

Re: Vibration during acceleration

I have already tried repositioning the drive shaft and that has not changed the vibration noticeably.

[Timothy B.]

Re: Vibration during acceleration

Well, I inspected the undersides of my car closely today and found that the drivers side exhaust pipe was almost touching the frame where it passes through behind the trans hanger (2.5" pipes). It looked like there had been evidence of contact. I removed and repositioned the drivers side exhaust system, and was able to get the pipe to pass through more centered in the large frame hole. I also checked for other possible contact points like the seat bolts, etc. mentioned in some of the responses and found no problems there.

On my first drive, it does seem improved. I suspect there was some contact during certain conditions. Thanks so much for the good input.

I did notice as I was carefully reving the engine slowly while sitting in the garage with the clutch depressed, that at about 2100 RPM I can feel a slight increase in engine vibration. This leads me to believe that some of what I am feeling might still be due to rotating parts such as the flywheel/clutch assembly. Or, I wonder how the front damper might contribute to this? I wonder if others have tried this same experiment in their car, slowly reving the engine while stationary and see if they can notice any appreciably change in vibration from the engine at various rpms?

Thanks for the great inputs!

[David T.]

Re: Vibration during acceleration

On my '64 many years ago, the nut on the differential pinion loosened up causing a vibration. Check the drive shaft U-joints at the same time. Good luck!

[John H.]

Re: Vibration during acceleration

That's a classic symptom of deteriorated bushings where the diff nose bracket bolts to the frame crossmember; allows the diff nose to rise under acceleration torque, the attachment goes metal-to-metal, and you feel the vibration. If the bushings are REALLY shot, it can allow the rear U-joint to scrape the tunnel.

[Timothy B.]

Re: Vibration during acceleration

I did notice as I was carefully reving the engine slowly while sitting in the garage with the clutch depressed, that at about 2100 RPM I can feel a slight increase in engine vibration. This leads me to believe that some of what I am feeling might still be due to rotating parts such as the flywheel/clutch assembly. Or, I wonder how the front damper might contribute to this? I wonder if others have tried this same experiment in their car, slowly reving the engine while stationary and see if they can notice any appreciably change in vibration from the engine at various rpms?

My vibration problem is still present, but now I see that what remains is in the engine or clutch assembly. My work on the exhaust pipes did get rid of some noise and made things smoother, but I still have vibration in the 2000-2200 RPM range with the car not moving.

So, I tried the trick of disconnecting the fan/water pump/alternator belt and that had no effect. Only the power steering pump remains connected. Is there a way to isolate the source of vibration? As I asked in an earlier post, should I be able to feel greater vibration at some RPMS?? Having the clutch in or out makes no difference.

[Gary C.]

Re: Vibration during acceleration

Barely touch the clutch pedal, rev up to 2000-2200 where you're feeling the vibration and see if you can feel it in the clutch pedal. If the vib's felt at the clutch pedal then look for something in that area. Good luck, Gary....

[Albert P.]

Re: Vibration during acceleration

Have you disconnected all drive belts and tested to eliminated fan, fan clutch, a/c, alternator?