if you adjusted your pinion angle, come in!

DiMora

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Then I guess I totally misunderstood Dimoras post on the last page. I'm gonna set them both at -3 to see if it clears up my vibe.

I always draw an exaggerated picture. Shoot imaginary laser beams out of both the tranny output and pinion input flange. Remember that if they are parallel, pinion is ZERO.

If the tranny output points up and the pinion input points down (imaging laser beams shooting out of each) and the laser beams miss, you have negative pinion angle, which is what you want.

If the laser beams cross (tranny output down rear pinion input up), you have positive pinion angle and that is BAD.

And, above all else, avoid sharks with frikkin' laser breams on top of their heads:

deathtraps-austinpowers-590x350.jpg
 

Fabman

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I got a nice high speed vibe that's a little bothersome.
I have that Tremec app as well and adjusted to be within the acceptable range (according to the app) and I still have this vibe.
I get it on the Freeway at high speeds and at the track as I approach the traps under power and on de acceleration too.
I go through the traps around 135 so I would guess it starts at something around 90 or 100 maybe?

See what you think:

http://youtu.be/uAGTFZemB5c
 
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Tbone

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I also have an issue. My car is lowered on eibach pros, BMR LCA + relocation brackets, and freedom racing UCA for lowered cars, and a dss driveshaft. Since I got that UCA for lowered cars, my pinion angle SHOULD (checking tomorrow to make sure) be correct. My only vibration and noise (like running over rumble strips) is at 65+ on deceleration only, and only for a few seconds until about 60mph. If i give it a touch of gas at 65+, same noise and vibration. Lots of gas noise goes away. Since this was a used driveshaft, if the angles check out, think maybe the ujoints are causing it? Its an older DSS with a ujoint at both ends with a slip joint. Also....I have the slip joint at the rear of the car, DSS says shouldnt make a difference. Thoughts on that?
 

BMR Tech

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I also have an issue. My car is lowered on eibach pros, BMR LCA + relocation brackets, and freedom racing UCA for lowered cars, and a dss driveshaft. Since I got that UCA for lowered cars, my pinion angle SHOULD (checking tomorrow to make sure) be correct. My only vibration and noise (like running over rumble strips) is at 65+ on deceleration only, and only for a few seconds until about 60mph. If i give it a touch of gas at 65+, same noise and vibration. Lots of gas noise goes away. Since this was a used driveshaft, if the angles check out, think maybe the ujoints are causing it? Its an older DSS with a ujoint at both ends with a slip joint. Also....I have the slip joint at the rear of the car, DSS says shouldnt make a difference. Thoughts on that?

Are you using a stock/OEM UCA Mount?
 

Fabman

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Okay, here is my situation.
I have a Coast alum drive shaft. I have a vibe around 80 mph.
I sent it back for a rebuild and they sold me a new driveshaft which I installed, and I still have the same vibration.
I called them today and they said that the Pinion angle has to be ZERO. They do not recommend any angle other than zero. (pinion and tail shaft angle the same or parallel) I told them about the video and that a couple degrees was considered a given and they were addamate that it had to be Zero. So WTH?
My current DS angle is 2* (trans down .5* and Pinion down 1.5*)
I have all tube/billet arms and poly bushings except the rear end housing upper bushing which is stock.

So....WTH?
 
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BMR Tech

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Okay, here is my situation.
I have a Coast alum drive shaft. I have a vibe around 80 mph.
I sent it back for a rebuild and they sold me a new driveshaft which I installed, and I still have the same vibration.
I called them today and they said that the Pinion angle has to be ZERO. They do not recommend any angle other than zero. (pinion and tail shaft angle the same or parallel) I told them about the video and that a couple degrees was considered a given and they were addamate that it had to be Zero. So WTH?
My current DS angle is 2* (trans down .5* and Pinion down 1.5*)
I have all tube/billet arms and poly bushings except the rear end housing upper bushing which is stock.

So....WTH?

On the S197....the most common pinion flange angle setting will/should be ZERO.

The problem with this whole deal is, 80% of people think "pinion angle" means...the actual pinion FLANGE angle..

The other 20% of the gearheads out there, think of pinion angle as the actual difference in angles.

Kind of like, when I talk to Flaming River about steering shafts, parts etc...and ask them about a "bumpsteer kit" - they respond with "I don't know what those are, but we have tie rod ends"

roflmao

So anyways...here is the deal.

Spicer, which makes most of the joints in these pieces, will typically recommend 1 degree of working angle on their joints.

They DO NOT want to see ZERO degrees of working angle on the joints.

Working angle is the angle of the DS in relation to the trans....which is your front working angle, and the angle of the DS in relation to the pinion flange...which is the rear working angle.

Those two angles should be equal/opposite under load.

Typical S197 Engines go "down" about 2-3 degrees or so.

If you set the pinion FLANGE angle at zero......then it will likely rotate up and be close to parallel to the trans/engine angle....and that means the joint working angles on each end of the DS will cancel each other out.
 

Fabman

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On the S197....the most common pinion flange angle setting will/should be ZERO.

The problem with this whole deal is, 80% of people think "pinion angle" means...the actual pinion FLANGE angle..

The other 20% of the gearheads out there, think of pinion angle as the actual difference in angles.

Kind of like, when I talk to Flaming River about steering shafts, parts etc...and ask them about a "bumpsteer kit" - they respond with "I don't know what those are, but we have tie rod ends"

roflmao

So anyways...here is the deal.

Spicer, which makes most of the joints in these pieces, will typically recommend 1 degree of working angle on their joints.

They DO NOT want to see ZERO degrees of working angle on the joints.

Working angle is the angle of the DS in relation to the trans....which is your front working angle, and the angle of the DS in relation to the pinion flange...which is the rear working angle.

Those two angles should be equal/opposite under load.

Typical S197 Engines go "down" about 2-3 degrees or so.

If you set the pinion FLANGE angle at zero......then it will likely rotate up and be close to parallel to the trans/engine angle....and that means the joint working angles on each end of the DS will cancel each other out.

Thanks for your reply.

Don't get me started on bumpsteer kits.
The vast majority of purchasers out there have never properly bumped their cars much less know how and why. But that's a story for another day.

I understand the correct way to set pinion angle, my problem is that it vibrates at EVERY angle.
I also replaced the driveline and adapter with no change...what else could cause this?
It's definitely speed related and in the rear and not a wheel balance problem, it's in the drive train somewhere.
BTW I have the BMR lowered engine K member so my trans is down less than a stock one. :blah:
 

BMR Tech

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Yeah, I don't doubt you know how to do it - I just wanted to clarify that the reason DS makers like to see ZERO on the pinion, is because that is the correct way to runt he pinion flange on 90+% of applications.

As for your issue, it definitely has me puzzled. I am not really sure what to say.

I know Lidio at Alternative Auto has told me on several occasions that he has never been able to successfully install a 1-piece DS on a 2005-2011 Mustang without getting some sort of vibration.

Personally, I have never had an issue.

If you have vibes at any angle configuration, you must have a hardware/mechanical issue somewhere IMO.

I wish I could be of more help.
 

Fabman

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Yeah, I don't doubt you know how to do it - I just wanted to clarify that the reason DS makers like to see ZERO on the pinion, is because that is the correct way to runt he pinion flange on 90+% of applications.

As for your issue, it definitely has me puzzled. I am not really sure what to say.

I know Lidio at Alternative Auto has told me on several occasions that he has never been able to successfully install a 1-piece DS on a 2005-2011 Mustang without getting some sort of vibration.

Personally, I have never had an issue.

If you have vibes at any angle configuration, you must have a hardware/mechanical issue somewhere IMO.

I wish I could be of more help.

No stress, just thought maybe there was something you've run into in your travels to explain it....
 

oldVOR

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Using a drive-on lift with a slight nose down attitude, I have the following measurements:

Transmission output shaft 1 degree down looking towards rear measured from drivers side.
Pinion input shaft 0 degree measured from drivers side.
Both these angles relative to ground, NOT the drive-shaft.

If I follow along correctly, the pinion input shaft should be adjusted to 1 degree up looking towards the front for a parallel path or 0 degree relationship with the transmission angle, which, would afford an even split between the static working angle of the trans/DS and pinion/DS.

If I'm interpreting BMR Tech's advice, I should leave it alone as the angular relationship is close to perfect for the setup I have at the moment: poly/spherical LCA's and poly/poly UCA or maybe adjust to 1/2 degree pinion down. This would allow close to a zero degree relationship between the trans and diff under load and keep the DS angles even under load.

Correct?
 

BMR Tech

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Correct.

If the trans is going down 1 degree....and the pinion is at zero, "IF" it goes up 1 degree under load, then the angles will be equivalent and cancel out.

You are absolutely on track, and with your combo...I would run it as is.

The reason for the "IF" comment I made, is because it is somewhat of a guessing game.
 

2007grabberGT

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Recently installed DSS one piece aluminum and adjustable UCA and LCA. I'm at -2 on the trans flange and about -0.5 on the pinion. Total pinion angle of -2.5 has yielded NO vibrations and driveshaft feels great. BUT..... I understand that because this driveshaft is a CV type, the angle is less critical?
 

Mark221

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I have mine set -3 from compared to driveshaft angle. I did not concern myself with the angle at the trans. I am running a roush steel 1 pc with the stock pinion flange. The aluminum adapter I indicated it in to be concentric to the flange to .001" and I have had no vibration at all.
 

hockeygod

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Thanks for the input. I just finished installing my bmr suspension this week which included the bmr adjustable upper control arm and mount. Going to be installing my new driveshaft for my new tremec t56 magnum xl and wanted to really understand how to set pinion angle in advance. One question I did have though was does that car have to be completely level and since I am doing this without a lift can the rear Axel be supported with jack stands while measuring and adjusting?
 

pics06gtstang

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Thanks for the input. I just finished installing my bmr suspension this week which included the bmr adjustable upper control arm and mount. Going to be installing my new driveshaft for my new tremec t56 magnum xl and wanted to really understand how to set pinion angle in advance. One question I did have though was does that car have to be completely level and since I am doing this without a lift can the rear Axel be supported with jack stands while measuring and adjusting?
best if done on a drive on lift , but yes can be done on ramps & stands
in a very careful manor .
THE picture i stole c/p , can y'all tell me whos car it is ? winner gets $ 1.00 payable thru PP .
jackstandPinionAngle.jpg
 
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hockeygod

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best if done on a drive on lift , but yes can be done on ramps & stands
in a very careful manor .
THE picture i stole c/p , can y'all tell me whos car it is ? winner gets $ 1.00 payable thru PP .
jackstandPinionAngle.jpg

So would you suggest one on jack stands leveling it by using a digital level on the frame rail to ensure levelness. Also once I begin to adjust pinion angle the car won't be completely level anymore so does that matter?
 

Wes06

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The car doesn't need to be level. Just the rear axle loaded like it was on the ground. Your measuring effective angle difference from the axle to the driveshaft
 

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