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Re: Why do Mopars vibrate??
[Re: 62maxwgn]
#529810
11/18/09 03:32 PM
11/18/09 03:32 PM
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Joined: Jul 2006
Posts: 4,319
Puyallup, WA
StealthWedge67
master
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master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
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If it vibrates, something needs to be fixed. My '67 Satellite, even at 3100 RPM with 3.91's out back, is very solid at freeway speeds.
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529813
11/18/09 05:07 PM
11/18/09 05:07 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Quote:
Seems like every old mopar I ride or drive in, they just vibrate (sort of like worn out U-joints).
My AAR does the same, and I hate the junker feeling it conveys when driving it...I replaced the u-joints, had the driveshaft balanced. Although better, it's still there. Just sitting (not moving) the steering wheel/column just resonates when running the engine through various speeds (i tried another factory harmonic damper)- still does it. Every time I talk about this with my friends, it seems like it's an accepted fact.
I can't stand it anymore - other than the obvious, what are some things I can do to smooth my car out? I haven't touched the rearend (8 3/4), but I wonder if changing pinion/axle bearings is necessary?
Thanks for any input!
Well, if it vibrates just sitting there, you can eliminate anything past the flywheel / torque convertor on the back side and you have already eliminated the balancer on the front side. That leaves: engine ( rotating assembly), flywheel or flexplate & torque convertor, unhealthy motor - includes partial miss or one cylinder down on compression or flat cam. Since it is the easiest to trouble shoot, I would proceed with the last item first ( verifying that the motor is healthy and hitting on all 8 holes evenly. In that regard, you might want to start with an rpm drop test. Next you might want to physically look at the flexplate and torque convertor for loose bolts / missing weights.
Fastest 300
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529814
11/18/09 08:01 PM
11/18/09 08:01 PM
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Joined: Feb 2004
Posts: 936
OLD318
super stock
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super stock
Joined: Feb 2004
Posts: 936
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Quote:
Seems like every old mopar I ride or drive in, they just vibrate (sort of like worn out U-joints).
My AAR does the same, and I hate the junker feeling it conveys when driving it...
Just sitting (not moving) the steering wheel/column just resonates when running the engine through various speeds...
Every time I talk about this with my friends, it seems like it's an accepted fact.
I can't stand it anymore - other than the obvious, what are some things I can do to smooth my car out?
Depending on your model year, you are in a 35-40 year old car. That's what they feel like...
You are use to modern cars and there is no comparing them (fairly) to one another...
Regardless...
For mopars dated up until 1972 you have to remember that the steering gearbox bolts directly to a steel K frame which bolts directly to a steel frame. So there is NO isloation between tire vibration, engine vibration and the steering gearbox to steering column. The result is
you feel everything with your hands on the column.
And no set of tires/alignment/wheel balancing
or sound proofing can fix this... Its the basic design.... and it is antiquated...
So no matter what you do, you cannot smooth out this feel in the steering wheel.
In 1973 (Take a charger for example)...
The K frame gets isolated from the front sub frame, and the column gets isolated from the gearbox... this is a big improvement in terms of "feel" at the steering wheel. But it is still not on par with cars of today, where you feel almost nothing... in say a Camry or an Accord or
just about any sizeable new car.
If you want to change the "old junker" feeling.
I suggest you try a modern sound deadener.
My recommendation would be a combination of 2 products Damplifier Pro followed by a layer of
Luxury Liner Pro... This stuff installed inside your doors, your entire bare floor pan from backseat to front firewall AND the roof skin.
As well as the trunk floor.
This will kill 80-90% of the sound/vibrations you hear and feel. You will be amazed at how solid the car will feel. But it will not correct 2 things... wind noise off of the front pillars/vent windows- which went away in 71-73 I believe, and that vibration you feel at the steering wheel.
Most mopar guys don't like this sound proofing stuff because it does add weight to the car and
does not look factory especially in the trunk.
It is also expensive and a little time consuming to put it.
However ,having done it... I would strongly recommend it... I was pleasantly surprised....
I have a 70 Coronet btw...
Best of luck to you!
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529815
11/18/09 08:03 PM
11/18/09 08:03 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Pure POWER!!! 
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Re: Why do Mopars vibrate??
[Re: Crizila]
#529816
11/18/09 08:05 PM
11/18/09 08:05 PM
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Joined: Jan 2004
Posts: 9,066
Eugene, Oregon
minivan
master
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master
Joined: Jan 2004
Posts: 9,066
Eugene, Oregon
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Quote:
Quote:
Seems like every old mopar I ride or drive in, they just vibrate (sort of like worn out U-joints).
My AAR does the same, and I hate the junker feeling it conveys when driving it...I replaced the u-joints, had the driveshaft balanced. Although better, it's still there. Just sitting (not moving) the steering wheel/column just resonates when running the engine through various speeds (i tried another factory harmonic damper)- still does it. Every time I talk about this with my friends, it seems like it's an accepted fact.
I can't stand it anymore - other than the obvious, what are some things I can do to smooth my car out? I haven't touched the rearend (8 3/4), but I wonder if changing pinion/axle bearings is necessary?
Thanks for any input!
Well, if it vibrates just sitting there, you can eliminate anything past the flywheel / torque convertor on the back side and you have already eliminated the balancer on the front side. That leaves: engine ( rotating assembly), flywheel or flexplate & torque convertor, unhealthy motor - includes partial miss or one cylinder down on compression or flat cam. Since it is the easiest to trouble shoot, I would proceed with the last item first ( verifying that the motor is healthy and hitting on all 8 holes evenly. In that regard, you might want to start with an rpm drop test. Next you might want to physically look at the flexplate and torque convertor for loose bolts / missing weights.
You forgot motor or transmission mounts..
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Re: Why do Mopars vibrate??
[Re: 340dart4spd ]
#529818
11/18/09 08:57 PM
11/18/09 08:57 PM
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Joined: Mar 2006
Posts: 1,611
Pataskala, Ohio
GTX70sixpack
top fuel
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top fuel
Joined: Mar 2006
Posts: 1,611
Pataskala, Ohio
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Vintage cars do not transfer drivetrain vibrations like many are describing above unless there is an issue.
You need to look at the engine mounts and the transmission mount. Sacked out mounts transfer a lot more vibration to the chassie. Another big culprit is the exhuast dead up agaist the frame, a torsion bar, the steering column etc; look for anything that is making solid contact.
My trans mount resently failed in my GTX when I was out thrashing on it pretty hard and it had a bad vibration at different rpm ranges in nuetral and a drone at highway speed (sounded like a out of balance drive shaft) dropped in a new poly mount and it's quiet and smooth again.
65 Belvedere II Station Wagon
69 Coronet R/T convertible
70 GTX
70'cuda
99 Dodge Diesel dually 4X4
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Re: Why do Mopars vibrate??
[Re: minivan]
#529819
11/18/09 09:45 PM
11/18/09 09:45 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Quote:
Quote:
Quote:
Seems like every old mopar I ride or drive in, they just vibrate (sort of like worn out U-joints).
My AAR does the same, and I hate the junker feeling it conveys when driving it...I replaced the u-joints, had the driveshaft balanced. Although better, it's still there. Just sitting (not moving) the steering wheel/column just resonates when running the engine through various speeds (i tried another factory harmonic damper)- still does it. Every time I talk about this with my friends, it seems like it's an accepted fact.
I can't stand it anymore - other than the obvious, what are some things I can do to smooth my car out? I haven't touched the rearend (8 3/4), but I wonder if changing pinion/axle bearings is necessary?
Thanks for any input!
Well, if it vibrates just sitting there, you can eliminate anything past the flywheel / torque convertor on the back side and you have already eliminated the balancer on the front side. That leaves: engine ( rotating assembly), flywheel or flexplate & torque convertor, unhealthy motor - includes partial miss or one cylinder down on compression or flat cam. Since it is the easiest to trouble shoot, I would proceed with the last item first ( verifying that the motor is healthy and hitting on all 8 holes evenly. In that regard, you might want to start with an rpm drop test. Next you might want to physically look at the flexplate and torque convertor for loose bolts / missing weights.
You forgot motor or transmission mounts..
 Did I mention checking motor and transmission mounts 
Fastest 300
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529820
11/18/09 11:18 PM
11/18/09 11:18 PM
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Joined: Jul 2005
Posts: 757
Toronto, Ont, Canada
boydsdodge
super stock
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super stock
Joined: Jul 2005
Posts: 757
Toronto, Ont, Canada
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I totally hear what your saying, it is an in and out droning vib felt thru the car after 3500 rpm starting at 70 and up.
On long drives where the speed limit is in the seventies it gets to be a real drag.
I went thru my dart from front to rear all mounts complete front end rebuilt with bushings. Checked pinion angle, tires, new drive shaft after ballancing three.
On this next build I have had the engine ballanced at a different shop hoping that might be the thing this time.
I feel this same vib in lots of mopars from pick ups, vans, 4 speeds, autos, it seems to be small blocks from what I have noticed and cast cranks.
mmmm, maybe something there.
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Re: Why do Mopars vibrate??
[Re: DennisH ]
#529822
11/19/09 09:09 AM
11/19/09 09:09 AM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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if it comes and goes with road speed, usually at multiples of the first speed (say, 30mph smooths out, comes back at 60, etc) check pinion angle. excessive pinion angle (like the 5 degrees nose down recommended for drag racing) can cause vibrations at cruise.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529823
11/19/09 09:36 AM
11/19/09 09:36 AM
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Joined: Jul 2005
Posts: 1,954
Blairsden, CA
Triggerfish
top fuel
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top fuel
Joined: Jul 2005
Posts: 1,954
Blairsden, CA
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My Challenger rides smooth as can be. Only vibration is from my teeth when the elephant wakes up at a stop sign. But my car's totally redone. My bro's 69 Charger drives like a dream & the ride in his 68 GTX was perfect, too. But those cars were totally restored, too. Be sure to check your steering box/front suspension, bushings, spindles, brakes & tires old or out of balance. One wheel may be tweaked from hitting a curb? As was said, there's a lot that can cause vibration including tail shaft bushings, trans mounts, u joints, rear end/axles, drive shaft...
I'd start w/ the tires, wheels, ball joints & bushings first.
Good luck.
Last edited by Triggerfish; 11/19/09 09:37 AM.
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Re: Why do Mopars vibrate??
[Re: kielbasa]
#529825
11/19/09 10:00 AM
11/19/09 10:00 AM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Chryslers fix was to hang a big chunk of steel off the tailshaft on later automatic cars. Think I have one if you wanna try it.
Fastest 300
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Re: Why do Mopars vibrate??
[Re: Crizila]
#529826
11/19/09 12:06 PM
11/19/09 12:06 PM
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Joined: Jan 2003
Posts: 27,451
So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,451
So Cal
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Quote:
Chryslers fix was to hang a big chunk of steel off the tailshaft on later automatic cars. Think I have one if you wanna try it.
I looked under a new mustang at the dealer and there's a bunch of chunks of steel under them. Also has a two piece driveshaft with CV type joints in it.
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