In my '85 z28 305 TPI 700r4.... I was driving along a mountain road, I hit where the road had settled. It was like a curb, only not quite as abrupt. The left front of the car got to it first. Sounded like some part of the frame hit, though I can't see any damage. That was the only thing that hit, but it wasn't a nice tap, it was a good thud and bounce.
Imediatly after when I drive... I get a nasty vibration that seems to come from the Transmission. It only happens under a load, and while accelerating. At anyspeed, under acceleration that isn't grandma.

Possible Transmission mount? What else could it be? Drives straight, just painful to feel and hear. Thanks.

 

First thing I'd check would be the driveshaft, it doesnt take but a little dent and they will vibrate.

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91 B4C 305 TPI - SOON TO BE 383
TREMEC 5-SP, STOCK 1-BOLT REAREAND w/342 GEARS, K&N, AIRFOIL
EDELBROCK HEADERS, DUAL CAT TO HOMEMADE Y-PIPE & 3.5" SINGLE PIPE W/ FLOWMASTER, CRANK PULLEY, MSD, FUEL PRESS REG, COWL HOOD, WELD WHEELS
14.1@ 98MPH
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OTHER RIDE
67 CAMARO - STREET CAR, BIG BLOCK, PUMP GAS
350TH w/ATI 10", 12-BOLT w/373 GEARS
10.94@124.13 ON MOTOR - ET-STREETs w/MUFFLERS

 

Seems weird that you'd get a vibration from the tranny if you didn't hit it on anything. It's hard to diagnose without seeing or hearing the problem, but the first idea I had was that maybe it's your exhaust rubbing on the frame or engine. If you hit the exhaust (more likely than the tranny) you could have moved it just enough that it rubs somewhere. I had an super-annoying vibration only on excelleration from my exhaust right after my header/y-pipe install. After repositioning the exhaust it went away. Just look under the car at the exhaust and see if anything looks too close to the frame or engine. Another possibility is that you bent a rim. But if that was the case, I think you'd have a vibration all the time.

 

Pretty sure I didn't bend a rim. The mount doesn't seem to be broken. I don't SEE the exhaust being too close, however there is a massive dent on the bottom of the muffler, and i can move the whole exhaust system from the cat back more than I ever could. Smacking the tail pipes or muffler, I can hear some vibration sounds *car off*. Dad thinks I have some play in the yoke of the tranny. Just a litte..... Uh where to go from here?

 

When in neutral, with the back wheels on the ground..... should I be able to turn the drive shaft? Because I can't.

 

No. With the back wheels on the ground the driveshaft shouldn't turn, even in neutral. If it does, the car will be rolling with it. Put the back wheels in the air and turn it in neutral. Then it should spin freely. Be sure to take the e-brake off too.

 

It's not the wheel weight, cause it would vibrate all the time. Checked U-joints, replaced Transmission mount, and exhaust doesn't appear to be too close, but the whole system makes more noise than it used to when I bang on the tail pipe. It makes it at 1500RPM then it makes it more prevalent from 2000-2500RPM. As well as higher RPM in sya passing gear. Thinking it's a drivetrain problem. The shaft was balanced and straightened 6 months ago, and I don't know how the bump would have made contact with it, or how it could have bent. The rear end gearing is all new from 6 months ago aswell.

Torque Converter? How would I check?

 

I may be going WAY out on a limb here but.....

You say the front left side of the car took the hit, but the muffler has a huge dent?

From that description I'd say the rear of the car is was took most of the impact.

Have you checked your rear shocks??

Reason I mention shocks is because someone else had similar vibrations and found out his rear shock was broken at the weld point.

The springs in the rear are strong enough to hold the car up and would allow for a broken shock to rattle.

Also check your front struts for damage as well.

If the shocks or struts aren't broken then I'd have to say the problem is in the exhaust somewhere.
Check your Y-pipe also. It could have knocked it close enough to something like the engine or tranny.

If the car took a hard hit on the rear could he have possibly bent the axle??

 

I believe the dent in the muffler came at a different point on that drive, before hitting the sinkhole type deal. It was definatly the left front of the car that hit. My passenger thinks so too. Will look at the shocks though. Thanks for the input!

[This message has been edited by ReDnEk27 (edited August 15, 2001).]