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FE Power Forums => FE Technical Forum => Topic started by: Royce on August 07, 2019, 03:31:09 PM

Title: Driveline vibration
Post by: Royce on August 07, 2019, 03:31:09 PM
My 61 Starliner has a resonating drive line vibration . The frequency leads me to the drive train... So far I have replace U joints,balanced the drive shaft,  inspected the axle bearings, and even changed out the gears.. No change... The vibration is rpm related and is worse under power and less if you let off the gas..I am 95% sure it is not coming from the engine compartment..  I would have put my money on the drive shaft but the shop said it was perfect.

Any ideas

RB
Title: Re: Driveline vibration
Post by: shady on August 07, 2019, 03:37:37 PM
Tranny output shaft bushing or bearing? Torque converter?
Title: Re: Driveline vibration
Post by: jayb on August 07, 2019, 03:38:16 PM
Which engine and trans?
Title: Re: Driveline vibration
Post by: machoneman on August 07, 2019, 03:40:00 PM
Has a clutch fan gone south?

Have you considered running the engine and drivetrain on a very well blocked up car? 
Title: Re: Driveline vibration
Post by: C6AE on August 07, 2019, 03:41:30 PM
"Hunting" gear set in the differential?
Title: Re: Driveline vibration
Post by: gt350hr on August 07, 2019, 03:43:09 PM
   Royce ,
      Look at your pinion angle. It could be pointing up too much and under power it rises even more creating a vibration. You may have already done that . It happened to me is why I relate it. Same MO , balanced , checked for straightness , new U joints etc. Bad angle.
    Randy
Title: Re: Driveline vibration
Post by: chilly460 on August 07, 2019, 04:54:15 PM
Following as I have same issue, not terrible but I’ve fixed all the other nagging items so will look into this over the winter.  Mine has a specific speed it occurs and it rolls in/out
Title: Re: Driveline vibration
Post by: Royce on August 07, 2019, 04:59:40 PM
Randy  Pinion angle passes the eyeball test but I will put a angle finder on it..

 Jay, I so want to say a 292 and a 3 speed... But it is a 390 and a C6  Trans output bushing is tight.. Pray it is not the torque converter.. It was replaced about 1000 miles ago with a higher stall unit.. Does not have a clutch fan.. Getting a the vibration to come and go by getting on and off the gas keeps me thinking somewhere between output on trans and rear gears
Title: Re: Driveline vibration
Post by: jayb on August 07, 2019, 05:08:30 PM
Royce, is this a new development or has the car always had this since you've owned it?  If its new, what changed around the time that it started vibrating?  I think it would be worth looking at the torque converter and flywheel.  Maybe somebody stuck a 428 flywheel on the 390, or a balance weight fell off the converter, loose converter bolts, loose flywheel bolts, or something in that area...
Title: Re: Driveline vibration
Post by: Royce on August 07, 2019, 05:21:07 PM
I barely drove the car when I bought it before pulling the motor for a detail job and a makeover to 390 375 horse dress.. I don't recall if vibration was present.. Since then it has a new converter but original flex plate. I put it all back together. (Definitely a possible source of error)  I'll check the converter bolts and see if I can see anything on the flex plate or converter..

Maybe Brad Ford  knows of some gizmo that can isolate sources of vibration
Title: Re: Driveline vibration
Post by: thatdarncat on August 07, 2019, 06:06:48 PM


...Maybe Brad Ford  knows of some gizmo that can isolate sources of vibration

BradFord is actually very good at diagnosing driveline vibrations, he’s helped me a couple times. Sadly no gizmo involved, you need the actual BradFord. A phone call to him might get some suggestions though. I haven’t been able to get him to check the forum on a daily basis yet.
Title: Re: Driveline vibration
Post by: badcatt on August 07, 2019, 06:36:18 PM
Does it do it in Neutral or Park? I'm chasing a vibration in a fresh 351C. I too thought it was drive line. But after R&Ring U-joints it still did it. I then checked in Park and it was there. Currently I do not have a diagnoses.
Title: Re: Driveline vibration
Post by: 66FAIRLANE on August 07, 2019, 07:26:33 PM
Had a vibe many years ago I couldn't find. Very subtle & only at higher speeds. One day a mate was driving behind me and when we stopped he said "I think your left axle is bent". I put a clock on the wheel rim & sure enough there was wobble, wasn't much, but was enough. Changed the axle, vibration gone. Just something else to check if its only there on road.
Title: Re: Driveline vibration
Post by: cattleFEeder on August 08, 2019, 07:17:25 AM
Just had the same problem on my 63.5 galaxie ended up being a wobble from an aftermarket rim that wasn't welded strait at the factory.
Title: Re: Driveline vibration
Post by: e philpott on August 08, 2019, 07:55:36 AM
Sounds like pinion angle to me too
Title: Re: Driveline vibration
Post by: Royce on August 08, 2019, 09:42:14 AM
I might spring for this ... Neat app...You could burn up 400 bucks at a shop pretty fast.

https://www.youtube.com/watch?v=GuI0hH2TuxQ][url]https://www.youtube.com/watch?v=GuI0hH2TuxQ (http://[url)[/url]
Title: Re: Driveline vibration
Post by: wayne on August 08, 2019, 11:01:32 AM
I put a pinon seal in and got a vibration i could not find a friend that worked for ford told me.Told me to take the drive shaft out and give it one half turn and bolt it back up it fixed it but i have no idea how.
Title: Re: Driveline vibration
Post by: Royce on August 08, 2019, 11:03:37 AM
angle at trans yoke is -1  driveshaft -5   pinion yoke -2  looks close enough not to be the root cause...  I may just throw in another set of U joints.. Engine is smooth up to 3000 rpm so I am inclined to eliminate that.. The frequency of the vibration steers me away from tires and wheels
Title: Re: Driveline vibration
Post by: 57 lima bean on August 08, 2019, 12:31:35 PM
Who's converter? And have you done a coast test from 80mph?
Title: Re: Driveline vibration
Post by: 338Raptor on August 08, 2019, 12:52:00 PM
Under load your pinion lifts changing your angle. If you have loose suspension bushings or weak leaf springs or a missing pinion snubber your pinion angle will change several degrees under load. You can’t measure this when the vehicle is parked.
Title: Re: Driveline vibration
Post by: C8OZ on August 08, 2019, 01:19:02 PM
A loose/broken transmission mount can do the same and often looks fine until you pry up on it.
Title: Re: Driveline vibration
Post by: Joe-JDC on August 08, 2019, 01:42:01 PM
Have someone help you put the rear axel of the car on jack stands just off the ground, and put the car in gear and accelerate through the gears while you watch for vibration in trans, drive shaft, rear end, tires.  The person in the driver's seat needs to be ready with brakes if the wheels and tires start to cause a bad vibration.  Will show if shock is bad, spring is broken, wheel bent, tire out of round, driveshaft out of phase, etc.  Easy to do, and should point you to the culprit fairly quickly.  Joe-JDC
Title: Re: Driveline vibration
Post by: WConley on August 08, 2019, 02:32:32 PM
Have someone help you put the rear axel of the car on jack stands just off the ground, and put the car in gear and accelerate through the gears while you watch for vibration in trans, drive shaft, rear end, tires.  The person in the driver's seat needs to be ready with brakes if the wheels and tires start to cause a bad vibration.  Will show if shock is bad, spring is broken, wheel bent, tire out of round, driveshaft out of phase, etc.  Easy to do, and should point you to the culprit fairly quickly.  Joe-JDC

+1   This works!  Use heavy jack stands and block the front wheels on both sides.  For extra insurance I will put a wheeled hydraulic floor jack up solidly on the rear axle pumpkin. 

I have had plenty of success with this approach.
Title: Re: Driveline vibration
Post by: machoneman on August 08, 2019, 02:56:42 PM
Hey! That's what is said at the start of this thread! LOL!
Title: Re: Driveline vibration
Post by: Royce on August 09, 2019, 04:51:43 PM
It appears to be engine related...It became more noticeable when I went from 2.91 to 3.20 gears.  As soon as you hit 31 or 3200 rpm things start to vibrate. I gotta check all the belts and bearings up front, but that new torque converter is laughing at me. Pulling the tranny  UGH. Don't have a lift    double UGH
Title: Re: Driveline vibration
Post by: machoneman on August 09, 2019, 06:44:41 PM
Btw, for safety if you do block it up, once you spin the drivetrain and check the wheels/tires, remove same. Car can't go anywhere now can it.
Title: Re: Driveline vibration
Post by: C6AE on August 09, 2019, 07:46:06 PM
Just take all the belts off the front and try it without them?
Title: Re: Driveline vibration
Post by: Joe-JDC on August 09, 2019, 09:24:38 PM
Check your motor mounts for two or three bolts.  Check block for two or three bolt holes.  Is there a possibility you have a later shortblock such as a 410, or 428 PI?  Then the original flywheel would be out of balance.  I know you pulled the engine for detailing, but did you think to check for motor mount holes?  Just an idea.  Joe-JDC
Title: Re: Driveline vibration
Post by: winr1 on August 10, 2019, 09:54:41 AM
Link to app


https://www.youtube.com/watch?v=GuI0hH2TuxQ



Ricky.
Title: Re: Driveline vibration
Post by: Joe-JDC on August 10, 2019, 01:25:40 PM
Link to app


https://www.youtube.com/watch?v=GuI0hH2TuxQ



Ricky.
Wow!  I was stationed at Hill AFB in Ogden UT when I returned from Vietnam, and I attended Weber State College at nights working on my Bachelors Degree.  Brings back some good memories of studies there.  Joe-JDC
Title: Re: Driveline vibration
Post by: Royce on August 12, 2019, 08:48:14 AM
Joe  the car vin says 352. When I had the motor out I checked and it is a 390 now.. It looks like a recent engine rebuild was done.. C1 block and heads  original style mounts.. 57 Lima Bean has me convinced it is a torque converter..How can anyone question Jay Brown's "riding mechanic" diagnosis.
Title: Re: Driveline vibration
Post by: e philpott on August 12, 2019, 08:55:13 AM
Royce I would send that converter to these guys http://www.dynamicconverters.com/aboutus.htm and have them check balance , if you like the Converter they can repair and not re-engineer the Converter , I have sent quite a few to them for repair , they can also tweak the stall up or down if want , the performance repair side is a great small group of guys that easy to work with for such a huge company
Title: Re: Driveline vibration
Post by: Royce on August 12, 2019, 10:31:22 AM
This is a Hughes street performance converter 2000 rpm stall it is about perfect for this application  . Relatively inexpensive so replace might be a better option than repair
Title: Re: Driveline vibration
Post by: gt350hr on August 12, 2019, 12:36:07 PM
  Royce if the vibration happens in neutral , you nailed it being the converter.
Title: Re: Driveline vibration
Post by: shady on August 12, 2019, 01:33:16 PM
I had a converter vibration that happened intermittently under load, never in neutral. ran hot too.
Title: Re: Driveline vibration
Post by: gt350hr on August 12, 2019, 03:06:46 PM
  That's a new one on me. Must have been the stator and turbine out of sync.
Title: Re: Driveline vibration
Post by: shady on August 13, 2019, 12:31:02 PM
It was a lock up converter, now that I think about it.
Title: Re: Driveline vibration
Post by: 57 lima bean on August 14, 2019, 11:32:46 AM
I had a converter vibration that happened intermittently under load, never in neutral. ran hot too.
   This is what I had asked Royce to do on jackstands floating the load with the brakes.Hope this is the cause and not some zany,madcap idea coming from listening to too much Beaker Street when younger.
Title: Re: Driveline vibration
Post by: Pentroof on August 19, 2019, 07:08:45 PM
I had a vibration in a new build that I absolutely had pinned down to a converter...or so I thought. Every other possibility in the driveline was eliminated with the 1700rpm vibration still happening in park with all the accessories off.

Well, it turns out my cam and my tri-Y headers generate a natural resonance and the passenger side pipe was barely touching the tranny crossmember. One large crowbar persuasion and 90% of the accentuation was gone.

Problem was, I had to replace the converter to convince myself to look at the exhaust. I may weld some large weights to the exhaust to kill the rest of it.
Title: Re: Driveline vibration
Post by: Royce on August 21, 2019, 02:09:53 PM
Well an epic fail on diagnosis so far. Replaced flex plate and converter and no change.  Unhooked all the accessories and no better. I think I have eliminated any problems from the engine back.. idling in neutral engine runs perfect. Makes plenty of power and no nasty mechanical noises,, Front damper has no run out.. Rev it up to about 2000 and it starts to vibrate and gets worse as you add rpm..I am suspecting internal engine problem   but what?

Title: Re: Driveline vibration
Post by: 338Raptor on August 21, 2019, 02:44:46 PM
Are you 100% sure you have the right damper? (Weighted vs non-weighted)
Title: Re: Driveline vibration
Post by: Royce on August 21, 2019, 03:36:27 PM
Yep  Early type damper..
Title: Re: Driveline vibration
Post by: GerryP on August 21, 2019, 04:16:44 PM
A misfire can cause a vibration.  Just because you don't have it at idle doesn't mean it's not there.  Any chance you can get your hands on an ignition scope?
Title: Re: Driveline vibration
Post by: machoneman on August 21, 2019, 04:43:09 PM
Well....I'll tell as quick as I can an now old story. Uncle Bill had a brand new '57 Ford Fairlane V-8 that had a weird and similar vib at highway speeds. The dealership looked everywhere. They gave up and called in a factory repr. He also came up empty handed...until he told the mechanics to pull the engine.

On teardown. he found one rod end, the big end IIRC, had not been machined at all and was therefore way out of balance. One new rod, checked for balance, and all was well.

Moral? If you're sure the balancer and 'wheel are o.k, a teardown may be in your future.
Title: Re: Driveline vibration
Post by: Joe-JDC on August 21, 2019, 06:56:21 PM
Do a quick stroke check to see if it is a 3.784 or 3.984".  I have a sneaky suspicion that the flexplate does not match the crankshaft.  I had a '69 R Code mustang that I bought with 4 speed, and it had the N heads, CJ cast iron intake, carb., exhaust manifolds, flywheel, four speed, etc., etc., and on the drive home it vibrated above 2000 rpm and just got worse the faster I drove.  Upon teardown, it was a 390 flywheel.  Looked perfect, looked correct, until you turn it over and see the weighted side was smooth.  The other scenario with imbalance(different car) that I experienced was a piston stuck and when I tried to start the CJ after it had sat for over a year, it would not turn over.  I thought it was just a weak battery, so I put a new battery in, and jumper cables to a running vehicle with the new battery.  It moved an inch or so, and then popped, and started running.  I drove the car for three years with a miss and vibration.  No amount of tuning would get that miss to go away.   When it finally broke, on teardown, there was a rod broken in three places.  The small end was still attached to the piston stuck almost at TDC, and the big end was still spinning on the crankshaft.  Had oil pressure, and felt strong, but vibrated.  I really have had three CJs that gave me problems since they first came out in 1968.  I like FEs, but the CJs have bit me several times.  Joe-JDC
Title: Re: Driveline vibration
Post by: Royce on August 22, 2019, 10:19:10 AM
Wish I could find an oscilloscope. Seems they have been purged from repair shops in the 90s. I found a potential issue as i am trouble shooting the ignition.. I measured voltage at the coil and got 12.7.. So naturally i think the resistor wire is missing.. Then i read up on the INTERNET and guess what, a dozen different opinions most of which sound bogus to me.. Anyway  there seems to be a disagreement on whether the reading you get, key on engine not running, is accurate if the points are open.. The theory goes that the resistor wire only drops voltage if current flows, which would be with points closed.. I missed exam on Ohms law.. What say Ye.  Oh  I just realized we have an electrical engineer in the group...Jay?
Title: Re: Driveline vibration
Post by: e philpott on August 22, 2019, 10:21:09 AM
you need to measure while running
Title: Re: Driveline vibration
Post by: Royce on August 22, 2019, 10:35:12 AM
That generated another online controversy.. The thinking goes like this..  since the current is switching on and off rapidly and the Multimeter can't keep up with the fluctuating voltage you get an inaccurate reading..I measured it running and it is 11.5 to 12V
Title: Re: Driveline vibration
Post by: RustyCrankshaft on August 22, 2019, 06:45:09 PM
That generated another online controversy.. The thinking goes like this..  since the current is switching on and off rapidly and the Multimeter can't keep up with the fluctuating voltage you get an inaccurate reading..I measured it running and it is 11.5 to 12V

If you have a peak hold function on your DMM you can still get a good reading. The meter is plenty fast enough to get the reading, but the display has to be dampened to a point the numbers are slow enough to be seen by eye.

They aren't as good as a true oscope, but Fluke has a pretty inexpensive "automotive" oscope/meter combo.
Title: Re: Driveline vibration
Post by: GerryP on August 22, 2019, 08:02:25 PM
There are a couple scope options.  A graphing multimeter, or a digital scope in either a hand-held oscilloscope or a laptop based scope, like Pico.

Ignition oscilloscopes and lab scopes in general have not gone away.  They are more critical today than in the days past when we used those huge Sun console tune up cabinets.  These days, if a sensor has a square wave output, the only way to see that is with a scope.  Most sensor issues are diagnosed with a scope.  They still use scopes for ignitions, it's just done mostly with sensor pickups rather than clip lines.
Title: Re: Driveline vibration
Post by: 57 lima bean on August 23, 2019, 09:30:46 AM
Glad only the wallet bleed and not your knuckles with wrenching.Some good hypotheses here.Maybe the points need sharpening?Hope to see you at the Radiation Race next month.I'll buy ya a beer and brat.
Title: Re: Driveline vibration
Post by: jayb on August 24, 2019, 11:21:23 PM
Royce, whoever said that the points need to be closed to check the voltage at the coil is correct, with the points open there is no current flow through the coil and thus no voltage drop across the resistor wire.  Close the points and check the voltage.  Also, I don't know of any multimeter fast enough to keep up with points that are opening and closing rapidly.  The multimeter would average the voltage readings from a rapidly changing voltage, so it would show a lower voltage than batter voltage, but not the actual voltage at the coil when it is charging.  Hope that helps - Jay
Title: Re: Driveline vibration
Post by: winr1 on August 25, 2019, 11:47:47 PM
If there is a resistor inline before coil ..... there should be ....

Voltage at + side of coil should be around 75% of battery voltage with mill not running

Same 75% of battery voltage with mill running

EDIT:

Have ya pulled all the belts and run the mill ??



Ricky.
Title: Re: Driveline vibration
Post by: thatdarncat on August 26, 2019, 10:28:40 AM
Wish I could find an oscilloscope. Seems they have been purged from repair shops in the 90s.

They still have an oscilloscope at BradFord’s shop, he used it to diagnose an odd problem on my race car a few years back, found it immediately with the scope. It helped immensely too, to have an experienced mechanic (BradFord) who recognized the issue as soon as he hooked up the scope. You really need to move to Minnesota Royce lol.
Title: Re: Driveline vibration
Post by: 57 lima bean on August 26, 2019, 12:04:03 PM
Recent communications with Royce have determined that zero voltage to the coil will diminish engine vibrations considerably.
Title: Re: Driveline vibration
Post by: Heo on August 26, 2019, 02:35:48 PM
Recent communications with Royce have determined that zero voltage to the coil will diminish engine vibrations considerably.

 ??? ??? ;D ;D
Title: Re: Driveline vibration
Post by: Royce on August 26, 2019, 07:18:22 PM
Steve, You are going to drive me to put an LS in this thing.  LOL
 Ignition research has halted till my in line diode comes..  And replace the radiator which was damaged when the shop dropped the tranny to change the converter, tilted the motor and put tension on the expansion tank.. and the hipbone is connected to the thighbone......a cascade of inter related issues.. Oh and now I have a giant tranny fluid leak to boot

Kevin a much better solution would be to get BRADFORD to move to Wi with tax incentives and increased salary and more favorable politics
Title: Re: Driveline vibration
Post by: Joe-JDC on August 26, 2019, 08:31:54 PM
You do know that the '61s still came with Y Blocks, also?  A 390 Y Block would be very cool.  Joe-JDC
Title: Re: Driveline vibration
Post by: Royce on August 27, 2019, 01:41:59 PM
Joe  Don't think I have not considered a Y Block!  I looked for a long time for a 60 or 61 Starliner with a Y-block. Seems the first thing guys did was rip out the venerable 292 and stuff in a 390.  Damn Shame...  I actually have a  Frankenstein 412 inch short block in the back corner of the shop.