if you adjusted your pinion angle, come in!

[rojizostang]

so on a stock DS i should messure it on the rear and the pinon flang the ds should be -2 and the flange 0?i have the pro-kit and my steeda adj uca will be here this week..i have the same angle finders in that video

i never measured the stock driveshaft angles. but if the pumpkin is nosed down 2 degrees, you should be fine. i assume you want to measure or set the angles because you're lowered?

my personal opinion is that worrying about the pinion angle with the stock driveshaft on a lowered car really is really overstated.

 

[CandyRedGT]

my guess is that if you're having vibe issues now, you'll still have them after installing the suspensions components. in fact, they could be a little worse since you'll probably have bushings that are a little harder than stock. if you're having vibe issues after just installing the drive shaft, imho the problem is with the shaft.

there are a lot of opinions that have been expressed in this thread...i see you're not not lowered, so i really doubt that your vibe issues are caused by anything other than the driveshaft....perhaps it could be a rear end issue if you did a gear swap also

control arms might help with traction if you're having a lot of wheel hop...but for better traction i think better stickier tires are going to help a lot more than control arms

I do NOT currently have any vibration. I've had it to 125 with no vibs. I was saying that i HOPE i do NOT after installing the after market arms/mounts. thanks

 

[JAY86]

this subject never really came to my attention before... my car has been lowered..... and I know the pinion angle definitely was not adjusted when the car was lowered.... I'm curious to know what driveshaft vibration feels like exactly? (srry complete new to car tech).... I have the stock driveshaft and plan to put in a adj. uca and lca's at some point but for the time being should I be worried about this?

How does the driveshaft vibration start exactly..... when you put a new one piece in? can you have this problem by simply just lowering your car?

thanks!

 

[scramblr]

O.K., so I'm getting stupid here, so help me out. It's been over two years since I've had the stock DS in there and I'm brain dead on adjusting the p/a. My understanding is to achieve the desired p/a, you take the DS measurement - the rear flange and that equals the p/a. I am taking the measurements from the right places, I think it's my math that sucks.

Well, I'm having a mathematical problem with this since the DS is at 1.7 and the flange is at -1.5. I'll never reach a negative angle with these measurements since 1.7-(-1.5) = 3.2.

I've got to be doing something wrong...someone slap me and set me straight.

 

[marcspaz]

You have to subtract one angle from the other to get the difference. That is your PA. The measured numbers are completely irrelevant, it is the measured difference that is important.

 

[Vapour Trails]

You have to subtract one angle from the other to get the difference. That is your PA. The measured numbers are completely irrelevant, it is the measured difference that is important.

So are you saying that it's the difference of the absolute values of the measured angles?

With his numbers it could be 3.2 or -3.2 depending on how you arrange the equation. If you take the absolute values, the difference is 0.2. Of course, you could never arrive at a negative result using the absolute values.

I've been reading various threads on PA and DS vibes for over an hour, and I'm just as confused as when I started.

 

[StageMe]

I have mine set at -4 and have had now issues and have been up to 155

 

[rojizostang]

I have mine set at -4 and have had now issues and have been up to 155

some say that a -4 pa is good for launching at the strip

 

[StageMe]

That is what I have heard and read in a lot of books...Ive had no problems with it what so ever

 

[marcspaz]

So are you saying that it's the difference of the absolute values of the measured angles?

With his numbers it could be 3.2 or -3.2 depending on how you arrange the equation. If you take the absolute values, the difference is 0.2. Of course, you could never arrive at a negative result using the absolute values.

I've been reading various threads on PA and DS vibes for over an hour, and I'm just as confused as when I started.

You are close. The measured numbers are not relivant, only the number value of the difference of the 2 measured numbers.

The positive or negitive number is based on the pinion gear. The pinion gear measurement is your imaginary zero line. Rgardless of was the measured level is, simply call that number zero. When you measure your shaft angle, if it is advanced of your imaginary zero point, you have a positive angle. It the shaft level is retarded compared to your imaginary zero point, you have a negitive angle.

Does this help?

some say that a -4 pa is good for launching at the strip

This is because during the hole shot, the rear squats slightly and the drive shaft and pinion gear will be as close to a straight line as possible. The greater the angle, the more loss you have at that joint. If there was no angle, just a straight line from the DS to the pinion gear, there would be the least amount of friction and loss.

 

[alloy6ix]

Spydershaft + Steeda Sport Springs. I've got NASTY vibration around 80mph.

Also, if I have a passenger in the car and gun it in 1st and 2nd the driveshaft will actually rub the tunnel.

I've got the Steeda Adjustable Upper and am getting the pinion angle adjusted this coming week. I will report the pinion angle they set.

Hope this fixes it.

Holy shit.. Any word on how/if you fixed this? I just got a spydershaft and currently have Steeda ultra-lites, but only the rear springs, stock fronts..

 

[dragpac]

so is the uds worth the trouble

 

[one eyed willy]

so i swapped out the uca today with a edlebrock adjustable...what a PITA!

i just want to make sure im clear on how to do the adjustments.

im using a digital sears magnetic dealio.

if im reading everything correctly and i want to go with -2 adjustment, i want the pinion to be -2 of what ever the 2nd driveshaft is,right?

so for example,if i have a +3 on the driveshaft, and +1 on the pinion,i would be -2?i know this is just dumb mathmatics but for what ever reason im having a problem with the way the adjustments were discribed.

 

[sqidds]

How to set your pinion angle correctly:

You can use jackstands to support the axle, ramps or a drive on lift which is best. The first thing you need to do is measure your rear ride height though. Measure the distance from the tire to the fender lift (vertically). This is your ride height. You HAVE TO check/set pinion angle at this ride height or you are wasting your time. You will find it is very hard to replicate the cars ride height if you are not using a drive on lift. I ended up using ramps with 48-lb of sandbags in the trunk to replicate mine. So there is your first challenge. You don’t do it right you are wasting the rest of your time.

The biggest misconception is what “negative” pinion angle is. Negative minion angle is an angle less than where you would set the driveline angles at in an ideal world where the axle doesn’t “wind up” under launch. If you are going for a -2* angle it needs to be X-2*, X being what the perfect driveline angle is. The perfect driveline angle is when the pinion angle and the transmission tailshaft angle are in “phase”. You need to set, or at least figure out then do the math based on the driveshaft being in “phase”. Here is a link that explains it in detail. Like ride height if you do not figure out what your driveline angles need to be set at to be in phase before you go adjusting for a negative pinion angle you are wasting your time. The angle of your driveline while in “phase” should be considers “zero”. If you do not find that zero you have on basis for any math from that point on.

http://www.roddingroundtable.com/tech/articles/driveline.html

Now that you have your driveline running in “phase” its time to set your driveline angle for dragstrip launches. If you are not doing drag launches you don’t need or want any negative pinion angle as long as you have quality control arms. The pinion changes angle very, very little if you have quality control arms. I have tested this with my data acquisition system and potentiometer hooked up to the pinion. Unless you are running drag radials and have at least 350hp leave your driveline set in “phase” or zero. Your pinion barely deflects when you drop the clutch with under 350hp or you are running real drag radials.

If you are putting down some pony’s and running sticky rubber the pinion will deflect when the clutch is dropped, but not much and not for long. -2* is pretty extreme and I would only run it for a car that was at the track a lot and getting 60ft times under 1.8sec. The reason being that if you are just driving down the road at -2* you are putting a lot of strain on your U-joints (they are out of phase) and the car will have less rear wheel horsepower. And lastly you will get a high speed vibration. For a car that has good control arms, goes to the track but also drives around on the street I would set it up at -1*.

Ok, back on point. So you are under your car and you have already set the driveshaft up “in phase”. If you want to set the pinion at -1* all you need to do is take the current pinion angle that you just set, which could be just about anything depending on if the car is level, etc. and adjust the pinion 1* down from there. A -1* pinion angle is simply your in “phase” pinion angle minus one. It is irrelevant what the in phase number is.

• Get a good digital angle finder.
• Have a few pieces of angle aluminum (the kind you can get at Home Depot) to use as a “base” for the gauge.
• Get the car in the air.
• Exactly replicate the rear ride height
• Put jack stands under where the K-member meets the floorpan then put your jack under the K-member right under the motor. Jack the jack up until the weight of the car is just coming off of the front jackstands. This is to remove the droop that the front end of the car has when supported by the “tub” and the wheels are not loaded. It’s a lot more than you would imagine and it changes the transmissions output shaft angle considerably. And unless your Trans output shaft is at the angle that it is while the car is on the ground you will not calculate your “in phase” angles correctly and everything after that will be wrong.
• Take your time
• Measure everything a BILLION times. There are a ton of variables. You will find that you will not get repeatable measurements unless you start to eliminate them. Only after you can take all of the measurements 3-4 times in a row with no changes have you eliminated all the variables.
• Keep in mind, 1* is very, very small. This is not a rough adjustment. It is therefore very easy to be 3* off just because of how you are placing the angle finder. This is where repeatability comes into play. If it does not repeat, you don’t know what you have.

 

[sqidds]

What the problem really is:

First it should be defined as what it is. It is not a driveline “vibration” problem but a driveline harmonics issue.

There is no way of guaranteeing that you will not have harmonics issues. Contributing factors to driveline vibrations are:

• Driveline angles
• Driveshaft balance
• Harmonics from the rear end which includes a change to the gear, diff, axles, bracing, cover, etc can all contribute to driveline harmonics.
• The wheels and tires you are running can contribute to driveline harmonics.
• The upper and lower control arms you are using can contribute to driveline harmonics.
• The springs and shocks can affect it too.
• Going with an aluminum shaft opposed to a steel shaft will affect harmonics even if they are the exact same design.

Pretty much anything can cause a driveline harmonics problems depending on the specific combination of parts. That’s why some people have no driveline harmonics issues and some do. There does seem to be a trend of the more aftermarket parts you have in your driveline the more likely you are to experience driveline harmonics issues though. That being said there are stone stock cars out there with harmonics problems.

How to really fix it:

The bottom line is that you can have perfectly balanced/round wheels and tires, perfectly set up rear end, perfect driveline angles, clutch centered perfectly, everything torqued to spec, etc and still have a driveline harmonics issue. In most cases you will not find that any one component is “out” and causing the harmonics issue. As stated above if all of the components that can affect driveline harmonics spec out perfectly on their own that does not guarantee you that when they are combined as a system you won’t have any harmonics issues.

I dug all my notes up that I took while mapping out the driveline angles in the chassis the other day and compiled them into something cohesive. The bottom line is Ford stuffed a huge motor with a very high crank centerline and a Trans with a relatively low output flange centerline into the front end of a car that they wanted a certain look from. Sacrifices were made. I know exactly how to solve the driveline angle issues in the car. On a basic level it’s easy. The problem is easy. The Trans output flange as delivered points at a point that is lower than the center of the pinion flange centerline even with the car not being lowered. It gets worse when the car is lowered. In a perfect world the Trans would point at a spot above the center of pinion flange. If it were set up like that you could get the driveshaft set up to be perfectly in phase (something like a DS angle of 1.5deg down coming off the trans and 1.5deg up coming off of the pinion). As delivered that can not be done because of where the Trans points.

It could be solved by shimming the Trans at the cross member till it pointed up a few more deg but there is not enough room between the Trans and the tunnel. Not even close. You can slam the Trans into the tunnel and you will only get .4deg out of it. You would have to move the tunnel to make it better. Obviously a lot of work.

Another way to solve it would be to lower the motor but even with the pan sitting on the steering rack I could only get .6deg out of it which was not enough. And obviously you can’t have the pan touching the rack anyway. And you can’t move the rack “down” because that would make the current bump steer issues even worse to borderline in-correctable. To compound the problem the back of the pan was quite a bit lower than the K-Frame which is just begging to get broken open. To get the motor low enough to even be in the ballpark you would need to dry sump it. Of course that would pay you back with a ton of performance advantages (lower C of G, more HP because of less windage, more HP because of the small vacuum placed on motor, oil stored in trunk which moves the weight to were you need it most, you could run a 10qt system if you wanted to and never have any oil issues, etc). Of course the downside is that it would be very custom, incredibly expensive, incredibly complex and nudge the car pretty far toward “race car”. I think at some point I will dry sump my car but that would be at least 2 more years and the car will be pretty far down the development phase by then and to a point where most people don’t want to take their cars.

If you combine shimming the Trans and lowering the motor as much as possible it’s still not even close to where you want it.

The last Idea I have to fix the situation, and one that would not be very expensive if done in a large enough quantity would be to remove the trans tail/flange and bolt on a custom mini “transfer case” that would simply raise the trans output flange up and therefore relocate the output flange higher. There is room in the tunnel for that because you wouldn’t be moving the large part of the Trans. And while designing it you could ditch the output flange in favor of a “normal” slip yoke so the driveshaft would not need to telescope like they do now which does not help the DS balance/whip/harmonics one little bit. I could make this part out of billet without much trouble and use some OEM 1:1 “transfer” gears of some sort so durability was already proven. The problem is making one would cost at least $3,000. If I could put them in production and make 1000 units I could probably do it for $500. I highly doubt I will find 1000 people ready to sign up for one though. It would be far less expensive for me to dry sump my motor and lower it in the chassis a ton.

So there ya go. It’s fixable to the point of having zero issues no matter what combination of parts you are running by setting the car up so you could obtain an ideal driveline layout but not one of them is very easy or cheap.

 

[Fabman]

What the problem really is:

First it should be defined as what it is. It is not a driveline “vibration” problem but a driveline harmonics issue.




There is no way of guaranteeing that you will not have harmonics issues. Contributing factors to driveline vibrations are:

• Driveline angles
• Driveshaft balance
• Harmonics from the rear end which includes a change to the gear, diff, axles, bracing, cover, etc can all contribute to driveline harmonics.
• The wheels and tires you are running can contribute to driveline harmonics.
• The upper and lower control arms you are using can contribute to driveline harmonics.
• The springs and shocks can affect it too.
• Going with an aluminum shaft opposed to a steel shaft will affect harmonics even if they are the exact same design.

Pretty much anything can cause a driveline harmonics problems depending on the specific combination of parts. That’s why some people have no driveline harmonics issues and some do. There does seem to be a trend of the more aftermarket parts you have in your driveline the more likely you are to experience driveline harmonics issues though. That being said there are stone stock cars out there with harmonics problems.

How to really fix it:

The bottom line is that you can have perfectly balanced/round wheels and tires, perfectly set up rear end, perfect driveline angles, clutch centered perfectly, everything torqued to spec, etc and still have a driveline harmonics issue. In most cases you will not find that any one component is “out” and causing the harmonics issue. As stated above if all of the components that can affect driveline harmonics spec out perfectly on their own that does not guarantee you that when they are combined as a system you won’t have any harmonics issues.

I dug all my notes up that I took while mapping out the driveline angles in the chassis the other day and compiled them into something cohesive. The bottom line is Ford stuffed a huge motor with a very high crank centerline and a Trans with a relatively low output flange centerline into the front end of a car that they wanted a certain look from. Sacrifices were made. I know exactly how to solve the driveline angle issues in the car. On a basic level it’s easy. The problem is easy. The Trans output flange as delivered points at a point that is lower than the center of the pinion flange centerline even with the car not being lowered. It gets worse when the car is lowered. In a perfect world the Trans would point at a spot above the center of pinion flange. If it were set up like that you could get the driveshaft set up to be perfectly in phase (something like a DS angle of 1.5deg down coming off the trans and 1.5deg up coming off of the pinion). As delivered that can not be done because of where the Trans points.

It could be solved by shimming the Trans at the cross member till it pointed up a few more deg but there is not enough room between the Trans and the tunnel. Not even close. You can slam the Trans into the tunnel and you will only get .4deg out of it. You would have to move the tunnel to make it better. Obviously a lot of work.

Another way to solve it would be to lower the motor but even with the pan sitting on the steering rack I could only get .6deg out of it which was not enough. And obviously you can’t have the pan touching the rack anyway. And you can’t move the rack “down” because that would make the current bump steer issues even worse to borderline in-correctable. To compound the problem the back of the pan was quite a bit lower than the K-Frame which is just begging to get broken open. To get the motor low enough to even be in the ballpark you would need to dry sump it. Of course that would pay you back with a ton of performance advantages (lower C of G, more HP because of less windage, more HP because of the small vacuum placed on motor, oil stored in trunk which moves the weight to were you need it most, you could run a 10qt system if you wanted to and never have any oil issues, etc). Of course the downside is that it would be very custom, incredibly expensive, incredibly complex and nudge the car pretty far toward “race car”. I think at some point I will dry sump my car but that would be at least 2 more years and the car will be pretty far down the development phase by then and to a point where most people don’t want to take their cars.

If you combine shimming the Trans and lowering the motor as much as possible it’s still not even close to where you want it.

The last Idea I have to fix the situation, and one that would not be very expensive if done in a large enough quantity would be to remove the trans tail/flange and bolt on a custom mini “transfer case” that would simply raise the trans output flange up and therefore relocate the output flange higher. There is room in the tunnel for that because you wouldn’t be moving the large part of the Trans. And while designing it you could ditch the output flange in favor of a “normal” slip yoke so the driveshaft would not need to telescope like they do now which does not help the DS balance/whip/harmonics one little bit. I could make this part out of billet without much trouble and use some OEM 1:1 “transfer” gears of some sort so durability was already proven. The problem is making one would cost at least $3,000. If I could put them in production and make 1000 units I could probably do it for $500. I highly doubt I will find 1000 people ready to sign up for one though. It would be far less expensive for me to dry sump my motor and lower it in the chassis a ton.

So there ya go. It’s fixable to the point of having zero issues no matter what combination of parts you are running by setting the car up so you could obtain an ideal driveline layout but not one of them is very easy or cheap.

Here's what you do bud....make that transfer case 2 speed....that way you can have stock gearing for street (or over-drive) and under-drive for racing....best of both worlds....plus you will take some strain off the drive line since part of the torque multiplication will be happening ahead of it. I bet some people would sign up for that....

 

[sqidds]

Here's what you do bud....make that transfer case 2 speed....that way you can have stock gearing for street (or over-drive) and under-drive for racing....best of both worlds....plus you will take some strain off the drive line since part of the torque multiplication will be happening ahead of it. I bet some people would sign up for that....

I have product design, development and testing scheduled all the way through April on my list. And then my busy season starts. I doubt I will tackle a “mini transfer case” idea anytime soon. And a 2 speed setup, which would obviously be very cool would take an incredible amount of R&D and cost a fortune to get to market. I’d have to sell 10,000 units just to break even! I’d love to do it but its just no feasible unfortunately.

 

[RONAELEGT550R]

What the problem really is:

First it should be defined as what it is. It is not a driveline “vibration” problem but a driveline harmonics issue.


There is no way of guaranteeing that you will not have harmonics issues. Contributing factors to driveline vibrations are:

• Driveline angles
• Driveshaft balance
• Harmonics from the rear end which includes a change to the gear, diff, axles, bracing, cover, etc can all contribute to driveline harmonics.
• The wheels and tires you are running can contribute to driveline harmonics.
• The upper and lower control arms you are using can contribute to driveline harmonics.
• The springs and shocks can affect it too.
• Going with an aluminum shaft opposed to a steel shaft will affect harmonics even if they are the exact same design.

Pretty much anything can cause a driveline harmonics problems depending on the specific combination of parts. That’s why some people have no driveline harmonics issues and some do. There does seem to be a trend of the more aftermarket parts you have in your driveline the more likely you are to experience driveline harmonics issues though. That being said there are stone stock cars out there with harmonics problems.

How to really fix it:

The bottom line is that you can have perfectly balanced/round wheels and tires, perfectly set up rear end, perfect driveline angles, clutch centered perfectly, everything torqued to spec, etc and still have a driveline harmonics issue. In most cases you will not find that any one component is “out” and causing the harmonics issue. As stated above if all of the components that can affect driveline harmonics spec out perfectly on their own that does not guarantee you that when they are combined as a system you won’t have any harmonics issues.

I dug all my notes up that I took while mapping out the driveline angles in the chassis the other day and compiled them into something cohesive. The bottom line is Ford stuffed a huge motor with a very high crank centerline and a Trans with a relatively low output flange centerline into the front end of a car that they wanted a certain look from. Sacrifices were made. I know exactly how to solve the driveline angle issues in the car. On a basic level it’s easy. The problem is easy. The Trans output flange as delivered points at a point that is lower than the center of the pinion flange centerline even with the car not being lowered. It gets worse when the car is lowered. In a perfect world the Trans would point at a spot above the center of pinion flange. If it were set up like that you could get the driveshaft set up to be perfectly in phase (something like a DS angle of 1.5deg down coming off the trans and 1.5deg up coming off of the pinion). As delivered that can not be done because of where the Trans points.

It could be solved by shimming the Trans at the cross member till it pointed up a few more deg but there is not enough room between the Trans and the tunnel. Not even close. You can slam the Trans into the tunnel and you will only get .4deg out of it. You would have to move the tunnel to make it better. Obviously a lot of work.

Another way to solve it would be to lower the motor but even with the pan sitting on the steering rack I could only get .6deg out of it which was not enough. And obviously you can’t have the pan touching the rack anyway. And you can’t move the rack “down” because that would make the current bump steer issues even worse to borderline in-correctable. To compound the problem the back of the pan was quite a bit lower than the K-Frame which is just begging to get broken open. To get the motor low enough to even be in the ballpark you would need to dry sump it. Of course that would pay you back with a ton of performance advantages (lower C of G, more HP because of less windage, more HP because of the small vacuum placed on motor, oil stored in trunk which moves the weight to were you need it most, you could run a 10qt system if you wanted to and never have any oil issues, etc). Of course the downside is that it would be very custom, incredibly expensive, incredibly complex and nudge the car pretty far toward “race car”. I think at some point I will dry sump my car but that would be at least 2 more years and the car will be pretty far down the development phase by then and to a point where most people don’t want to take their cars.

If you combine shimming the Trans and lowering the motor as much as possible it’s still not even close to where you want it.

The last Idea I have to fix the situation, and one that would not be very expensive if done in a large enough quantity would be to remove the trans tail/flange and bolt on a custom mini “transfer case” that would simply raise the trans output flange up and therefore relocate the output flange higher. There is room in the tunnel for that because you wouldn’t be moving the large part of the Trans. And while designing it you could ditch the output flange in favor of a “normal” slip yoke so the driveshaft would not need to telescope like they do now which does not help the DS balance/whip/harmonics one little bit. I could make this part out of billet without much trouble and use some OEM 1:1 “transfer” gears of some sort so durability was already proven. The problem is making one would cost at least $3,000. If I could put them in production and make 1000 units I could probably do it for $500. I highly doubt I will find 1000 people ready to sign up for one though. It would be far less expensive for me to dry sump my motor and lower it in the chassis a ton.

So there ya go. It’s fixable to the point of having zero issues no matter what combination of parts you are running by setting the car up so you could obtain an ideal driveline layout but not one of them is very easy or cheap.

How ironic,
This is the same problem that I have ran into right now. I have changed out the motor and put a new TKO-500 in my S197. I have had to drop the motor to the point where it was touching the rack. Shimmed the back of the trany intil it hit the tunnel and still have terrible angles. The shifter I had to use to fit the factory opening is quite a bit different than a regular shifter. It hits everywhere. I have had to cut on it and trim down the linkage arms quite a bit. I have an ajustable 3rd link on the rear end so the pionon angle is easy to set but the trany angle has been a bitch. Currently it is a-.3 deg down and the drive shaft is at -.7 deg down which nets a -.4 deg at the trany. The rearend pinion is at 2.7 which nets a -2.0. The difference between the rear angle and the trany angle is 1.6 deg which is a long way from cancelling out each other. It really aint worth a shit but what do you do. I will be running a 1.6 deg angle under hard launches and probably more under normal driving. won't know if there will be a vibration or if I will tear something up until I try it. Only thing left to do is cut the hole in the tunnel a little bigger and clearance the shifter linkage some more but I don't think I can pick up any more than 1/2 degree but I guess that is better than nothing. That would put me around or under 1 deg of total pinion angle and I think that is in the safe zone.
It's really a pain in the ass when things don't work like they ought too. Looks like a poor design from ford.

 

[JesseW.]

ok guys, little engineering lesson. driveshafts all have a natural frequency at which per given rpm they will begin to viberate. in older cars, a lot of them had problems with viberations between 55-65 mph. that is because in high gear the driveshaft would be spinning right around it natural frequency. length and diameter have a big influence on where the actual speed is, and it sounds like these single piece shafts are longer and larger in diameter that older driveshafts which would explain the vibe being around 80 mph. aluminum also has a different modulus of elasticity from the old steel shafts that would affect the speed too.

what can be done to correct this? figure out the rpm the shaft itself is turning at 80-100 mph and have it balanced there. placements of the balance weights have a big impact and can move the natural frequency to a higher rpm and higher speed.

This is why there are a lot of rear drive cars with 2-piece driveshaft, its a lot harder to reach the natural frequency on a shorter shaft and easier to balance.

i know chevy had a fix for the aluminum driveshafts on thier trucks that involved drilling a hole in them and filling them with foam. anybody want to experiment? adjusting the pinion will have some affect on balance because of the way the joints run, but it probably wont be a cure-all.

 

[08gt4u]

need your help guys.
i try adjusting my pinion angle yesterday and when i put the car on the lift with all 4 tires under load and i got +2 on the pinion flange and +3 on the driveshaft side.i did adjust my uca and that moved the pinion to a 0 and the driveshaft to +3.on the side note it moved the vibration from 90mph to 115mph.
taking in account my 1st settings of +2 and +3 where would i want to be for a correct setting or where im at is correct?