driveline vibrations

Topic: driveline vibrations (Read 11846 times) previous topic - next topic

driveline vibrations

Reply #60 – May 27, 2011, 01:54:53 PM

Quote from: 347Thunder;360728

I know you might not want to hear this but you gears might be setup wrong

They could be setup wrong, but I highly doubt it. The guy that did them for me the last time is very good. Most of his business is axles and driveline stuff for high performance applications (circle track, drag cars, etc).

driveline vibrations

Reply #61 – May 29, 2011, 03:09:05 PM

I'm going to guess a bent axle shaft or perhaps a bad rotor. That's got to be it. I have 3.73s and my drive shaft does not vibrate at all. I chased a vibration problem for a year or so till I found a bent passenger side axle. If the car was fine previous to the rear swap then it has to be the rear.

Just a FYI but if you have a bent axle I'm going to bet you'll need a new rotor and pads on the side with the bent axle. When I replaced the axle on mine I had to replace the drum and shoes on that side as well. Since the axle was bent it ended up egg shaping the inside of the drum.

driveline vibrations

Reply #62 – May 29, 2011, 04:44:29 PM

There was a bronze bushing inside the back of the tailshaft housing that when replaced helped some with a vibration, but it was an auto.
It might help to check lateral and radial runout to eliminate some components.
Also knowing what order the vibration is a possible way to eliminate some components.
It's been a long time since NVH class but I think there are 1st, 2nd and 3rd order of vibrations when dealing with vibrations in the majority of vehicles in locamotion. You may be able to use a simple small engine tachometer that measures frequency and then calculate what order the vibration is.

driveline vibrations

Reply #63 – May 29, 2011, 09:14:25 PM

Saturday I took off the rear wheels and spun the axles to check to see if they were bent. From what I can tell they are fine. The rotors and brake pads look perfect. I did rotate the tires and it did not change the vibration at all.

I'm going to take her on power tour and just try to stay below 75 mph, that's where it really vibrates. I really don't think its a bent axle...I'm wondering if maybe it has something to do with lowering the car so much. I found this writeup and it really helped me understand the importance of u-joint angles, etc: http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

Tomorrow I'm going to get the car on jackstands and check everything one more time with the driveshaft, pinion angle, etc.

driveline vibrations

Reply #64 – May 30, 2011, 11:09:49 PM

Quote from: 50tbrd88;360732

They could be setup wrong, but I highly doubt it. The guy that did them for me the last time is very good. Most of his business is axles and driveline stuff for high performance applications (circle track, drag cars, etc).

I hear ya, the guy that did my 3.73's did them perfect, but 8 years later the 4.33's were aweful, and he has done a lot of gears since then, also he is a good friend of mine, but even when I took him for a ride he said it was the drive shaft.

driveline vibrations

Reply #65 – April 16, 2012, 11:04:41 AM

Just in case anyone finds this thread someday looking for answers to a similar problem--I did have a custom aluminum driveshaft made by Action Machine in South Bend, IN and the vibration is now gone.

driveline vibrations

Reply #66 – April 16, 2012, 03:39:50 PM

That was probably the best $300 you ever spent.lol

driveline vibrations

Reply #67 – April 16, 2012, 03:58:37 PM

Quote from: 347Thunder;386966

That was probably the best $300 you ever spent.lol

I'm sure it was.. I had a 70 mph vibration problem too in my old tbird and it really made me hate driving the car.

Good Fix 50tbrd88!

driveline vibrations

Reply #68 – April 16, 2012, 08:33:02 PM

Thanks guys...the enjoyment level of driving the car has gone up with the new shaft!

driveline vibrations

Reply #69 – April 17, 2012, 05:27:38 AM

Hooray! I loathe vibration issues. I never liked my Merkur after going to a T5. I tried and tried but never got it totally smooth. That gearbox hated that chassis harmonically.

Driveshafts all flex, and the steel one must have had a 'bad' harmonic in your combo. the aluminum one must dampen that out, apparently.

Good thread! Sticky worthy?

driveline vibrations

Reply #70 – April 17, 2012, 09:14:36 AM

You said "shaft"....

I can make fun of it now that that car is fixed.

Darren

driveline vibrations

Reply #71 – April 17, 2012, 10:38:12 AM

Quote from: 50tbrd88;386986

up with the new shaft!

he he he.

driveline vibrations

Reply #72 – April 17, 2012, 12:10:48 PM

I was about ready to give the whole car "the shaft" for awhile...it was that frustrating. I'm glad that's all behind me now.

driveline vibrations

Reply #73 – April 17, 2012, 12:24:17 PM

Quote from: 50tbrd88;387032

I was about ready to give the whole car "the shaft" for awhile...it was that frustrating. I'm glad that's all behind me now.

A vibration you can't find is the worst. I have one in my van that I've been chasing for years. I'm at the point of F it and just drive it till it rattles it self apart.