Vibration between 50 & 70 mph

[Lo Pony]

I see what your saying: its not all the way perfect, but i don't feel anything at all now at any speed. That's acceptable to me..and yes i understand that its not really perfect over all until you start putting the devices on it that can locate the specific areas of imbalance and then eliminate the things you cant feel.

See my previous post also, and all the tech I've posted here (and throughout the years - do a google search "lo pony drivetrain vibration"). I've been chasing this problem since 2002 on earlier '99-'03 IRS mustangs, and I know a thing or two about the problem.

If it's gone to where you can't feel anything and you're satisfied, then I would say that you are done. Congrats. This is a complex problem and can have many variables involving the driveshaft, flange, differential, pinion angle, etc.

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[Lo Pony]

That means the clamp is too heavy. FIrst, index the shaft at each bolt hole. If no improvement, add washers under the pinion flange bolts. I would choose a washer that is half the weight of the hoseclamp screw and receiver and move it around to each bolt.

No easy way without an EVA.

If you're finicky, get ready for some troubleshooting time, since this problem is VERY sensitive to rotating mass. FYI, I fixed my '99 with a new, zero-runout flange and TWO machine washers under adjacent pinion flange bolts - one of them ground down to be half the weight of the other. I did not use an EVA - I did the whole thing by seat of the pants and it took many hours. Hoseclamps around the driveshaft were way overkill (i.e. too heavy - worsened the vibration in all positions).

If you want it all the way gone, you'll have to work at it...or live with it.

You can do a great service to your colleagues here, and this message board by taking good records and posting all your results.

 

[Lo Pony]

Look how sloppy the center carrier bearing rubber mount is on the OEM 2-piece driveshaft (go to time 2:55). Wondering if that contributes to the vibration problem. If the rubber is so compliant, it seems it could cause the driveshaft to go into some kind of harmonic vibration if the shaft isn't perfectly balanced.

Could be - if it's REALLY loose.

But probably not if the rear mount, DS runout and flange are talking to each other properly. I'm still thinking there's an issue at play regarding why so many cars have the vibration appear after a few thousand miles, i.e. a "soft part". This could be the hanger bearing, or the IRS diff shifting in the frame...so many things. Usually, pinion angle problems manifest themselves in 3rd gear about 38 MPH during acceleration or decel (at least that's the way it used to be).

 

[Unadilla248]

That means the clamp is too heavy. FIrst, index the shaft at each bolt hole. If no improvement, add washers under the pinion flange bolts. I would choose a washer that is half the weight of the hoseclamp adjustment assembly, and move it around to each bolt.

How heavy is the hose clamp adjustment screw and assembly? You can find out for yourself by taking a hose clamp and cutting the metal band off it and weighing the "adjuster" part on a balance that will give you an accurate reading down to hundredths of a gram.

No easy way without an EVA. Sorry guys - text me if you want to work through this - I can tell you how to do it.

I cut the hose clamp I was using and weighed it today at my work on an accurate scale and it measured 0.48 OZ and also weighed some different washers from 0.19 OZ to 0.23 OZ and took them home to try under the pinion flange bolts, Another thing thats currently on my mind is I planned on putting a one peice driveshaft on this car eventually so im contemplating maybe just installing sooner but not shure yet.

 

[Cobra Jet]

Question for those trying to perform the hose clamp fix at home:

Are you just jacking up and safely supporting the rear in the air - indexing driveshaft then testing while in air OR mounting hose clamp, then getting in the car to run it through gears to see if you can feel the vibes??

I'm trying to understand how some of you are performing the adjustment or fixes at home - safely - and with minimal "up/down, up/down", etc. with the vehicle.

Or are you indexing OR installing the hose clamp, then taking the car down off the stands and driving it to see if vibe has decreased?

 

[ABS550]

Phil
I sent you a PM

 

[Unadilla248]

Question for those trying to perform the hose clamp fix at home:

Are you just jacking up and safely supporting the rear in the air - indexing driveshaft then testing while in air OR mounting hose clamp, then getting in the car to run it through gears to see if you can feel the vibes??

I'm trying to understand how some of you are performing the adjustment or fixes at home - safely - and with minimal "up/down, up/down", etc. with the vehicle.

Or are you indexing OR installing the hose clamp, then taking the car down off the stands and driving it to see if vibe has decreased?

I put mine up on 4 jack stands then ran car in 5th gear to 55mph because that's the gear and speed I feel vibration in the most on the street.

I only attempted this once so far and my process was I would do a run to 55mph then put tranny in neutral and gently touch the brakes to stop wheels then quickly get under car and index clamp a small amount and repeat with another run to 55mph, I could definitely notice a difference depending on clamp location but I didn't have enough time that day to try different methods such as separating 2 clamps or washers on pinion flange, I also put a big fan in front of car and kept eye on water temp with torq app.

Also vibration is definitely more significant up on stands than on street.

 

[CB]

It doesn't have in your post but I would think the jack stands should be located under the suspension so you can test for vibration with the angles of the half shafts the same as when running down the road.

 

[ABS550]

It doesn't have in your post but I would think the jack stands should be located under the suspension so you can test for vibration with the angles of the half shafts the same as when running down the road.

Given that it is the DS that is being balanced, it is unaffected when the wheels are off the ground and the half shafts are allowed to hang.

I did mine successfully using the pinch welds as jacking points.

How did you do yours? Was it successful?

 

[Unadilla248]

Did mine on the Steeda Jacking Rails.

 

[Lo Pony]

I cut the hose clamp I was using and weighed it today at my work on an accurate scale and it measured 0.48 OZ and also weighed some different washers from 0.19 OZ to 0.23 OZ and took them home to try under the pinion flange bolts, Another thing thats currently on my mind is I planned on putting a one peice driveshaft on this car eventually so im contemplating maybe just installing sooner but not shure yet.

Hey Man - good deal and great start. If I were you I would wait on the 1 piece driveshaft until you can get a couple of things sorted out. Sorry if I didn't read your posts enough, but have you indexed the rear shaft all the way around the pinion flange yet? If not, do that first. If so and no improvement, then see if you can make an improvement with the washers.

I've tried running the car on jack stands supported at the rear control arms, but in my experience it does not allow you to feel the vibe as well as driving on a smooth street.

I would start with putting one 0.23 oz washer on the bolt closest to the yellow dot. Drive car. If no improvement, move the washer 180 deg. to other side. If needed, then hit the 90 deg. positions. Check back with us.

If you want to chat about the problem over the phone I can talk to you about the problem and help you troubleshoot or diagnose. PM me.

 

[Lo Pony]

New iPhone App Compatible with External Strobe for Vibration troubleshooting

I managed to talk to an app developer friend. This is for the serious do-it-yourselfer who has some electronics skills, but shows you how to connect an external accelerometer and strobe to your iPhone and use it as an EVA.

I have not had time to test this myself, but once everything is wired up it should be straightforward. However, I do not know how well it will work. Please let me know if you try it, and if it does work, remember to thank the App developer. He's a super friendly and helpful guy and I'm sure he'd be happy to help us if we have questions.

Go to the App Store and get the "Vibration Analysis" software from Dmitriy Kharutskiy, and look on usefulmobileapps.com

There might be a $2-3 in-app fee for getting the app set up, not sure.

Here is the link to the website (and yes, he acknowledges me as the person who proposed the App).

http://usefulmobileapps.com/en/vibration-spectrum-analysis.php#stroboscope

youtube video
[ame]

If you are going to tackle the vibes yourself, please PM me and let's walk through the troubleshooting procedures. I am very interested in finding out how this works.


Thanks!

 

[Lo Pony]

Question for those trying to perform the hose clamp fix at home:

Are you just jacking up and safely supporting the rear in the air - indexing driveshaft then testing while in air OR mounting hose clamp, then getting in the car to run it through gears to see if you can feel the vibes??

I'm trying to understand how some of you are performing the adjustment or fixes at home - safely - and with minimal "up/down, up/down", etc. with the vehicle.

Or are you indexing OR installing the hose clamp, then taking the car down off the stands and driving it to see if vibe has decreased?

It's worth a try to do it on jack stands, and CB (see prev. post) is correct that you need to support the car underneath the rear control arms to properly load the suspension. I never had any luck with this method coupled with "seat of the pants". So, I ended up having to jack up the car, scoot under, make adjustment, let car down and take it for a drive. But if you have a vibration meter (see my post above) you might get lucky and be able to make an improvement.

By all means, observe all possible safety precautions.

 

[CB]

Given that it is the DS that is being balanced, it is unaffected when the wheels are off the ground and the half shafts are allowed to hang.

I did mine successfully using the pinch welds as jacking points.

How did you do yours? Was it successful?

My car doesn't have any problems. But I did have the vibration problem with a 99 F- 250. After a few repair attempts the Ford district representative said it was a characteristic of the vehicle. Just like many of the Mustangs here, the problem started after thousands of miles so it's not a characteristic. That's when I told him, You know what the characteristic of an asshole is? It's someone that's full of shit just like you. And that pretty much put an end to him liking me.

 

[markw24]

My car doesn't have any problems. But I did have the vibration problem with a 99 F- 250. After a few repair attempts the Ford district representative said it was a characteristic of the vehicle. Just like many of the Mustangs here, the problem started after thousands of miles so it's not a characteristic. That's when I told him, You know what the characteristic of an asshole is? It's someone that's full of shit just like you. And that pretty much put an end to him liking me.

LOL ROTF:lol::lol::lol:

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