always faster

iTrader: (6)

Well lets make this straight,the title is not for bashing but to bring attention and help

I got a spohn adj TA that mount on the tunnel brace and the brace is made for LT.I got it for 2 years now.I ve tried a lot of angle but this damn thing makes a regular howling noise when i reach 65mph and over.

It also makes a lot of vibration when im around 75mph the feeling is totally unbearable.The shifter shake a lot.I stop making higway trip since then(2 YEARS DAMNIT )

I ve bought a new spohn HD driveshaft,new poly tranny mount,also a stock one to.I ve check every mount,any slack and verify the torque of the bolts of the TA.

Now here is the funny thing.My friend(2002 SS) just bought the same one and you know what????It does the exact same stupid thing...

I ve talk to Steve at Spohn and Ryan at Umi and they both of them recommend to put the TA to 0degree when street driven.

So we took both of car TA and adjust the pinion angle to 0.Mine was 86 on the DS and 86 on the TA so my angle is dead on 0.

My buddy got 88 on his DS and 88 on his TA so again dead on 0.

We ve test them and both of the car got the same problem.It makes this regular noise and vibration at 60mph and vibrate heavily and from the shifter at around 75mph.


So what do i do with this.Is there something that i dont know.I did not put 15k on my car to drive it at 30mph in city and no drag or road circuit race.

When my car was 100% stock,the first mod i put on it was this TA and the noise and the vibration began at this exact moment,so the TA is the main problem in my case.
I ve used this method(SPOHN):
"
There are two angles to deal with:

1) Driveshaft angle
2) Pinion angle

You subtract pinion angle from driveshaft angle to get TRUE pinion angle

Here's how you do it:

First, had you measured your stock drive shaft angle and pinion angle before you removed your stock torque arm, you would have calculated a 0 deg. TRUE pinion angle. This is how all cars come from the factory, no suspension bind.

Using an angle finder place it on the driveshaft (a flat smooth spot) and record the angle indicated.

Next, place the angle finder on the flat surface where the torque arm mounts to the rear end (this surface is parallel with the pinion shaft) and record the angle indicated.

Subtract the pinion angle from the driveshaft angle. The result is "TRUE Pinion Angle".
In order to apply preload you need negative TRUE pinion angle. Adjust the torque arm so that the front of the pinion goes down; continue to check each angle until the pinion angle is more degrees down than the driveshaft angle.

We recommend –1 degrees on a mildly modified daily driven car. For high horsepower applications we have gotten the best results with –2 to –3 degrees. There is no reason to run more negative then that, it will actually hurt your performance because it will induce driveline bind."

onfire

iTrader: (17)

http://www.markwilliams.com/driveshafttech.aspx

You're setting your pinion angle in the wrong manner. I've used the Spohn TA for 3 years...no noise and have run it 9.6 at 141mph....

Forget the driveshaft angle....means nothing.

Look at the above link. You have to measure the down angle of the trans shaft and make the pinion angle parallel that angle under load so it looks like the above picture.

Example: If the trans shaft is pointing DOWN 3 degrees then the pinion angle would have to point UP 3 degrees to be parallel with no load. Since the rear differential is not solidly mounted it will rortate upward around 2 degees under load....so you deduct that from the measured angle and set the pinion angle UP 1 degree so it will parallel the trans shaft angle under load.

Measure your trans shaft angle with the driveshaft out of the car and go from there....I bet it will be close to 3 degrees down.

onfire

iTrader: (17)

http://www.rosslertrans.com/Pinion%20Angle.htm

Another example of the same way to do it.

Forget the trans poly mount also...just adds vibration.

3.4camaro

iTrader: (1)

Word. That thing vibrates more than my solid motor mounts. I replaced it with the stocker

Solid motor mounts + rubber trans mount = no shifter shake, no interior noise

always faster

iTrader: (6)

Ok so the fact that the ds and the diff must make a "V" is not true.

All that i need to do is put my car on the 8 concret block that i ve bought just for that(stack by 2) to have to car on his own weight.I use this method since its cheap, put the car higher and gave me more room to work under it.

Then take the DS off and take the angle of the tranny output shaft and the pinion angle.If i get 4.5 degree down for the tranny,i need 2.5 degree up for the pinion so it would match the tranny shaft under load.

Am i right?
And also is this method good for the street?

Thanks

onfire

iTrader: (17)

That's the way. Good for both the street and track. Only other advice I have is to borrow a digital angle finder....I hate using the needle types since you can barely read 1/2 degree and the needle can stick against the back and give a false reading. A good way to get the trans shaft angle is the use the flat side of the trans yoke. Turn it until it's 6:00 and lay the angle finder against it.

Good luck.

INMY01TA

iTrader: (1)

I've heard you start by measuring the angle of the crank pulley.

always faster

iTrader: (6)

Ok bring this post up.

Me and my friend follow your instructions.My friend got now really really small noise wich is a big improvement,we will try bringing up the pinion just a little to make it shut.

On my side it didnt appear to change anything I ve oreder a 80$ digital angle finder since i cannot find a place where i could rent one here in canada.

I know that the poly trans mount will transmit more vibration but could this little mount be the culprit of all the major vibration that i got????

onfire

iTrader: (17)

Absolutely

always faster

iTrader: (6)

Ok so i will try to find a ls1 trans mount since those are better than lt1 unit.

Duffster

iTrader: (103)

Try www.wixey.com they are intended for tablesaw & woodworking use, but it costs 40 and can read to .1 degrees. . .

always faster

iTrader: (6)

Damn!!! Mine is already order and paid for:
http://cgi.cafr.ebay.ca/Pro-360-Digi...QQcmdZViewItem

always faster

iTrader: (6)

I was thinking about that since im having a hard time finding a oem ls1 trans mount here for a fair price...does an jobber one (napa,autozone) would do the job too???

Thanks

CW00BlackTA

iTrader: (31)

Onfire is right.

You can use a measurement from the face of the crank pulley since it's normal to the crank centerline which is parallel to the trans centerline.

Last, I put some 3/8th pads of rubber between the body and the body mount to help with reducing transmitted vibration.