THE CHOP SHOP

iTrader: (7)

I have noticed this vibration for quite sometime. I have a 98 TA that was all stock when I was going to school. The wierdest part of the situation is that when i was going to school and driving on the highway 60 miles three times a week it go away but when i would take the summer off and not get on the highway for a couple months the car would shake once I started back and after a few trips it would go away. I thought maybe i got used to it but I know it really did get better once I was on the highway more. i dont know what caused this but do the rest of you guys drive alot of highway and still get vibration or just get out on the highway once and a while. My rear has made quite a bit of noise since 02 when i got it and it had 42k on the clock. I now have 68k and plan on doing some bearings soon so I dont hurt anything more than I already have.

Marc '99T/A

iTrader: (22)

When mine were going out, the noise sounded like a rumble; like a wom-wom-wom. And it was progressive with speed also. I replaced all the bearings in my rear end and the axles (they had worn areas from the bad bearings). After that, the noise was gone, but I still have the vibration.

5.7LoFuN

iTrader: (1)

that sounds like what mine is doing the wom wom wom sound, too bad that didnt fix your vibration though... ill def have to check those out

to answer someone elses questions

NO i have not checked my pinion angle, i dont have an adj. TA, so i couldnt really adjust this anyway. Im going to get one soon though, my factory one is bent

I used Eiabach Prokit only the LT1 version....a fraction less drop than the LS1 prokit, but it has a stiffer spring rate in the rear to properly compensate for the lower ride height.

I have non-adjustable Lower control arms ( UMI ) AND lower control arm relocation brackets

I also have an adj PHR for what its worth



i still dont get this drive shaft thing....the whole thing spins so why would it matter if you rotated it before you installed it, it would eventually rotate through the same position and the U joints are lined up on the shaft so the only thing i could see beind different by not marking how you took it out would be the U joint would be flipped, and thats a symetrical piece. Also the yolk wouldnt be in the same spot but its just a round shaft that slides in. That would also mean that the guy who balances your drive shaft would have to know which way you were installing it to balance it, if it made a difference....which makes no sense to me ( if anyone understood that) I guess i just cant visualize the difference.

ANYWAY is there anything i could do to check if the driveshaft is in properly( even though i already have taken it in and out without marking it) ?

LETHL_SS

iTrader: (21)

That would def throw off your angle and could cause the vibration.

5.7LoFuN

iTrader: (1)

yeah, i just looked under the car a few days ago and from what i could tell it appeared to be bent, ill have to get it up in the air to get a better look at it. Im going to get an adj TA anyway though...Im supised though, because i would have thought the TA being bent, it would launch funny. I still think i might have a problem with the bearings in the rear so im going to check those out as well.

Foxxtron

iTrader: (1)

Not to imply that anyone here doesn't know how to set and/or adjust pinion angles, but here's two somewhat useful resources:

http://carcraft.com/howto/91758/
http://www.wolferacecraft.com/pinionangle.aspx

Don't know if the moderators will allow the second link to remain or not, since I don't see them as a sponsor for this website.

5.7LoFuN

iTrader: (1)

thanks for the links, those will come in handy once i get the adj TA in

Xtreme57

iTrader: (6)

Depress the clutch (or put it in neutral if a4), if the wine is still there, you can at least rule out the trans. I had a problem very similar to this, and it turn out to be damage to my rear end gears. New gears, no problem anymore. Good luck bro.

StripedZebra

iTrader: (6)

I was thinking of checking my rear gears. If i remember right, when i put the shifter in neutral it makes it go crazy! If i pull of my rearend cover, and something is messed up, should i be able to notice right off?

And just cause its not trans related, it could still be something in front of the trans, right?

Xtreme57

iTrader: (6)

It's hard to say. You might be able to notice if the teeth are messed up bad enough, but sometimes something little can get magnified exponentially at X,000rpm.

As far as the front of the trans, where does it sound/feel like it's coming from? Mine sounded and felt like it was right under my ***/beneath the trans, but it ended up being the gears.

StripedZebra

iTrader: (6)

It feels like its comin from under the center console (the armrest).

Demon_Speeding

iTrader: (24)

I just got done installing;
- Moser 9" rear
- UMI adjustable PHR and LCAs. They are the poly/rod end combo.
- Spohn body mount Torque Arm.

Talk about vibration. I took it yesterday to the hobby shop on base and stuck it on a drive on lift. After a little time with an angle finder I adjusted the pinion angle. What a difference! 95% or better of my vibration is gone. I know my tires are out a little, as well as my driveshaft. Once my taxes come in I'm getting wheels/tires and a new driveshaft.

Xtreme57

iTrader: (6)

I would check out the gears. I'm not sure with our cars, but i know the older cars, you could just drain the rear end fluid and run it through a filter to check for metal shavings/debris. Maybe you could try that before taking the rear apart?

LFNDUST

as mentioned before had same problem, and all my suspension was new tires balanced, my clutch was old and worn out, car was vibrating like hell, replaced clutch flywheel, and took care of vibration problem!!!

silverlt1ss

i had a similar problem when i put a used ile driveshaft in. i took it out had it balanced and had the same problem. for ***** and giggles i when i had the driveshaft out i turned the yoke on the rearend and put the shaft back in. boom no more vibration. i heard when the factory installs the driveshaft they some how balance it with the rear yoke. a gm tech told me when i take a drive shaft out to mark it the one end of the u joint to whare it was with the yoke.

Gearhead1

I just found the vibration in mine tonight that's been driving me nuts. When heated stainless steel exhaust systems "grow" lengthwise up to 1 inch. That's a given and that's why they're mounted into rubber isolaters like they are. Well, I went from an aluminized exhaust to a stainless one and I didn't take the expansion difference into account when mounting the new exhaust. Come to find out it was expanding so much that it was binding the whole length of the exhaust in the rearmost passenger side mount. I pulled it down, trimmed it a bit and lo and behold no more vibration. I know for a fact that I've checked that stupid exhaust three or four times looking for a place where it could be hitting, but it was always with the engine (and exhaust) cold. Duh!!

StripedZebra

iTrader: (6)

That gives me hope!

When i get my headers and y pipe on im gonna run cat-back-less for a bit, and i know if that was my vibration!

Auto cars have flywheels right?

Gearhead1

On the auto cars they're flexplates.

CW00BlackTA

iTrader: (31)

I might as well throw in my story. New 9 inch, Spohn body mount TA, drive shaft and u-joints. Got it all together and had nasty vibration. Adjusted TA and improved but not eliminated. Put stock Al drive shaft back in and made it much better--almost gone. Had heavy duty steel shaft balanced with new joints again and still had vibration. On some advise, checked runout of pinion yoke. It was out of spec. Replaced it and things improved some. Adjusted pinion angle a million times three different ways and it makes a difference but haven't been able to eliminate significant vibration. Bought adjustable panhard rod and centered everything a much as possible--no diff. Car is not lowered--not changing anything else until I figure out the vibration issue.

Gave up on it for a few months but tomorrow the battle starts again. Plan to try another set of wheels, more TA adjustments and if needed, a different center section. If none of that works, the axles and bearings come out for examination and testing. If the new yoke was out of tolerance, something else could be. Sucks to have a fast car that's only fun to drive under 70!

Let's keep this going until we figure out some more causes.

Mike2000Z28

Yeah someone needs to figure this out. To many fast cars, too many mustangs to be embarassed out there to have a 70mph limit, sucks....