Author Topic: bad vibration  (Read 130043 times)

Offline philo_beddoe

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Re: Pulsating vibration at 50
« Reply #30 on: January 07, 2016, 07:17:05 AM »
Still has the vibrate under load, getting frustrated! Feels like something out of balance. Foot on gas going down the road it vibrates, take foot off gas, smooth as butter.  Idk.
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline Greybeard

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Re: Pulsating vibration at 50
« Reply #31 on: January 07, 2016, 09:14:08 PM »
I've had that problem before but right now I don't recall what it was. CRS. Is the vib a slow one or really fast? Does it follow engines revs or tire revs? Or neither depending on which gear it's in?
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Offline Captain Swampy

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Re: Pulsating vibration at 50
« Reply #32 on: January 07, 2016, 09:49:52 PM »
I would take your driveshaft out and turn the joints by hand. Sometimes one cap will get dry and bind up. It takes awhile to wear enough to get sloppy, but rotating by hand you'll feel it.

It is possible your balancer slipped. How old is your distributor? The bushings may be getting bad and throwing the timing off.

You could try putting a few hose clamps on the driveshaft. Line them up so the tighteners are in a row. What your doing is adding a balancing weight. Then test drive and see if it's better or worse. Move them and try again. If you get rid of the vibration, your shaft needs to be balanced. Takes a while to mess with but it works.
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Offline philo_beddoe

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Re: engine vibration at 50
« Reply #33 on: January 07, 2016, 09:59:01 PM »
Well to start, i am grateful someone finally got back to me, thanks!!

The vib is fast, not skippy or hesitant, it is present even in park or neutral. It follows engine revs. The dist, plugs and wires are new. Egine idles smooth, vib is present when you rev in neutral or accelerating of course. It really feels like something is not balanced. Its at my mechanics now, should know something tomorrow. If i had a heated garage, i'd have her all to peices by now.
« Last Edit: January 07, 2016, 10:27:47 PM by Irish_Alley »
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline Captain Swampy

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Re: engine vibration at 50
« Reply #34 on: January 07, 2016, 11:15:01 PM »
That helps narrow it down! Cross fire between 5 & 7 is common, make sure wires are seperated. Maybe pull the valve covers and watch the rockers, possible bad cam. Try a new balancer, it's only money, right?  ;D  I wish I had a garage also. Pray for us both to acquire garages this summer!
1987  350TBI 700R4  4X4  4.56 gears  33" BFG All Terrain


http://forum.73-87chevytrucks.com/smforum/index.php?topic=32209.0

Offline philo_beddoe

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engine vibration at 50
« Reply #35 on: January 08, 2016, 06:52:23 AM »
Maybe we should have brooke take a look at it, she would probably figure it out quicker than i could!!! 


Thanks and will do!!
« Last Edit: January 08, 2016, 07:13:40 AM by philo_beddoe »
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Online bd

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Re: engine vibration at 50
« Reply #36 on: January 08, 2016, 08:53:22 AM »
In a new unit of time, regardless of what has been done or how recently, check the firing order (1-8-4-3-6-5-7-2) and the routing of the spark plug wires.  When it is dark outside, raise the hood and look closely for arcing between any of the plug wires and the engine.
Rich
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In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Rattler12

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Re: engine vibration at 50
« Reply #37 on: January 08, 2016, 09:38:08 AM »
Assuming by the Park/Neutral comment you have an automatic......Flex plate has a crack/cracks in it between one or more of the holes in the crank mounting surface......under power it wobbles, not it doesn't.....you can thank me later..... :)
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Offline zieg85

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Re: engine vibration at 50
« Reply #38 on: January 08, 2016, 09:39:49 AM »
I have also had a clutch fan cause an intermittent vibration
Carl 
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Offline philo_beddoe

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Re: engine vibration at 50
« Reply #39 on: January 08, 2016, 09:40:01 AM »
Update:  transmission mounts shot! Will this cause it, does this make sense?
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline zieg85

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Re: engine vibration at 50
« Reply #40 on: January 08, 2016, 09:42:21 AM »
Update:  transmission mounts shot! Will this cause it, does this make sense?

yes it would, yes it does make perfect sense
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline zieg85

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Re: engine vibration at 50
« Reply #41 on: January 08, 2016, 09:44:15 AM »
further more I've seen it shake the transmission bolts loose from the engine and in one case crack the TH350 aluminum housing
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline philo_beddoe

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Re: engine vibration at 50
« Reply #42 on: January 08, 2016, 11:27:07 AM »
Thanks zieg, glad we caught this one. I HATE anything vibrating or making noise. I dropped a marble in my friends heater vent once as a joke, that marble bobbled around like crazy. Very cruel thing to do.
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline philo_beddoe

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Re: engine vibration at 50
« Reply #43 on: January 08, 2016, 11:36:06 AM »

Assuming by the Park/Neutral comment you have an automatic......Flex plate has a crack/cracks in it between one or more of the holes in the crank mounting surface......under power it wobbles, not it doesn't.....you can thank me later..... :)

Will check!! And bd i'll keep an eye on those wires. We put new wires, plugs and dist. cap back in oct.  Will triple check firing order but as mentioned, she idles real smooth.
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline philo_beddoe

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Re: engine vibration at 50
« Reply #44 on: January 08, 2016, 04:45:06 PM »

Assuming by the Park/Neutral comment you have an automatic......Flex plate has a crack/cracks in it between one or more of the holes in the crank mounting surface......under power it wobbles, not it doesn't.....you can thank me later..... :)

Well it wasnt the tranny mount. Could be that flex plate/flywheel. I could swear it is starting to sound like a helicopter! Getting discouraged and depressed!! My engine mounts arent that great, but there is some rubber there.  Idk...
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1