Installed driveshaft today...vibration issues

Maybe someone can help me out, I installed my 1-piece d/s today and I have atrocious vibration only after 90 mph. It's mild while accelerating, moderate when I let off the throttle and absolutely horrendous if I brake from that speed and above. I'm only lowered ~1" in the rear but I haven't corrected my pinion angle...can't imagine it would off by much of anything...

I feel like a kid who's scoop of ice cream fell off the cone...and magically landed on a plate on the sidewalk...only to be trampled by someone walking by

BlakJak87 wrote:

I feel like a kid who's scoop of ice cream fell off the cone...and magically landed on a plate on the sidewalk...only to be trampled by someone walking by

Sorry no advice, but that S@%# is funny right der.

Why not try reinstalling it and turn it 180 degrees.

I have read where folks have had vibration issues after installing their D/S and went back and turned it 180 degrees before they reinstalled it and it was fine. It wouldn't hurt to try.

Andrew, there is a LOT of information out there about vibration after 1 piece shaft installs on s197s, and note that a properly installed one piece USUALLY does NOT require changing the pinion angle with a modest drop like that. With my Steeda springs, I added an adjustable UCA, checked the pinion angle, and it was fine!

When problems happen with one piece install, everything from problems with the balance on the shaft to incorrect installation (rotated and bolted in 180 degrees from what it should be, incorrect adaptor install or flange, etc). Even your mph vibration target is fairly common. There is a ton of info for you to sort through.

I would do searches on s197forum.com and forums.themustangsource.com using "driveshaft" and "vibration".

Who makes the driveshaft? Shaftmasters? Spydershaft? Coast?

It's a Shaftmasters direct bolt-in. I did not replace the pinion flange.

I'm a bit fuzzy on the "180 degrees off" concept.

1. During installation, I marked the position of the stock driveshaft as a reference in case I had to throw it back on in the future. These marks did not line up, they only coincided with bolt positions at each end.

2. Before we took the stocker out, I had unbolted 5 of the CV joint bolts and 2 of the tranny output flange bolts while the *stock shaft was still in place*. I realized that I wouldn't be able to easily orient the driveshaft to my original markings given that one looked like 5 o'clock and the other looked like 3 o'clock or something bizarre like that.

3. To remedy this, I made a second set of different-looking markings that would line up to EXACTLY 6 o'clock on both sides. Those 6 o'clock markings are what I used to orient the new d/s.

My question is, for the 180-degrees-off fix, do I completely unbolt both ends of the driveshaft, rotate it 180 degrees, and bolt it back on? I may have accidentally fully rotated the tranny output flange, while the pinion flange was not rotated, but I still installed the driveshaft according to my 6 o'clock markings. Would that have caused an issue, and should the tranny output flange get rotated?

Thanks!

I would mark the DS at the pinion flange pull it out, and turn it 180 degrees and bolt it back in. Then test.

What he said. If that's not it a bit more sleuthing will be necessary...

Jeo, should I unbolt the tranny output flange too or can that stay bolted on?

A Shaftmasters rep told me to keep turning the tranny output flange 90 degrees, simultaneously turn the pinion flange 120 degrees and then test for vibration. I'm going to try a 180 degree turn first.

If my rotations don't work, the shaft has to go back..

I would unbolt the from the trans too. I had to do the same with my car. I still had a slight vibe but it was way better then when I first installed it.

If you can't remedy the situation it sounds like Shaftmasters did exactly what the name implies.

Low 11s wrote:If you can't remedy the situation it sounds like Shaftmasters did exactly what the name implies.

Oh Damn, lol

Does the Shaftmasters come with an adapter plate for the 05+ style pinion hub?

If so that is the #1 reason for vibration. Horrible design...

As said you will have to unbolt it, move it around to another bolt hole until it possibly balances...

Usually this is a PITA...

The main reason I went Spidershaft, it uses a conventional pinion hub.

jeostang wrote:

Low 11s wrote:If you can't remedy the situation it sounds like Shaftmasters did exactly what the name implies.

Oh Damn, lol

TT_05_Stang wrote:Does the Shaftmasters come with an adapter plate for the 05+ style pinion hub?

If so that is the #1 reason for vibration. Horrible design...

As said you will have to unbolt it, move it around to another bolt hole until it possibly balances...

Usually this is a PITA...

The main reason I went Spidershaft, it uses a conventional pinion hub.

It's a direct bolt-in design. No pinion flange adapter plate needed.