Driveline vibration
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Joined: Feb 2012
Posts: 77
From: Western Mass.
Driveline vibration
I have a Rallye 350 4 speed and I have been trying to diagnose a vibration issue, the vibration only happens when the car is in gear. I had a new rear axle installed and I was told that the pinion angle could cause a vibration,and another person told me it could be a bad rear tranny bearing among other possible causes.
Any thoughts would be appreciated Thanks
Any thoughts would be appreciated Thanks
Last edited by jtdb153; Jun 9, 2015 at 06:31 PM.
Beer Connoisseur
Joined: Aug 2008
Posts: 2,092
From: Daly City, California
On one of my cars the driveshaft started coming apart due to the rubber between 2 pieces being worn out, started vibrating pretty bad. Ended up having a 1 piece driveshaft made.
You may need your's rebalanced.
You may need your's rebalanced.
Last edited by 70cutty; Jun 8, 2015 at 08:55 AM.
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From: Poteau, Ok
Is there a particular speed that its happening? Does the vibration increase or decrease with speed? Are there any funny noises associated with the vibration? Does it go away when you push in the clutch? Is it present in all gears?
Thread Starter
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Joined: Feb 2012
Posts: 77
From: Western Mass.
It happens in all speeds but does decrease in forth gear(60mph). There is a funny noise and the only way I know how to explain is that it sounds like a Whrrrr sound coming from under the dash area. The sound goes away when the car is in neutral,but while in neutral if I press the gas pedal the noise can be heard. If I press the clutch in the noise does slightly go away.
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Joined: Oct 2009
Posts: 42,475
From: Poteau, Ok
Is there a particular speed that its happening?
You said its at all speeds, but decrease in 4th @60
Does the vibration increase or decrease with speed? Is there a rhythmic or harmonic note to it, like tire balance?
Are there any funny noises associated with the vibration?
You said there is a whirring noise from under the dash and goes away when you push in the clutch and more pronounced when you give it gas.
Does the vibration go away when you push in the clutch?
Is it present in all gears?
You said its at all speeds, but decrease in 4th @60
Does the vibration increase or decrease with speed? Is there a rhythmic or harmonic note to it, like tire balance?
Are there any funny noises associated with the vibration?
You said there is a whirring noise from under the dash and goes away when you push in the clutch and more pronounced when you give it gas.
Does the vibration go away when you push in the clutch?
Is it present in all gears?
Thread Starter
Registered User
Joined: Feb 2012
Posts: 77
From: Western Mass.
Registered User
Joined: Dec 2012
Posts: 1,589
From: Texas
I believe the driveshaft has to be indexed correctly. Not the correct term i know but I forgot what its called. It can be 180 degrees out, rear U joints must be alligned correctly. Engine broken down for restoration?, possibly a bad clutch disc/ pressure plate, was it balanced? And all balanced together at the same shop? I had a clutch builder, do the pressure plate and disc for my Vette, supposedly balanced. Long story short the car shook so violently, it was like an over grown vibrator. Took it to the shop that did the engine, found it to be 55 grams out of balance! New pressue plate and clutch disc neutrally balanced and all was good.
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Joined: Oct 2009
Posts: 42,475
From: Poteau, Ok
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
Possibly you have a bad layshaft bearing. All power is sent via the layshaft except in top gear.
But check first the driveshaft is properly aligned and balance weights haven't fallen of it.
Roger.
But check first the driveshaft is properly aligned and balance weights haven't fallen of it.
Roger.
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