tryin to figure out my vib over 65mph(update with hoping ist fixed)

92sclikenew

Registered User
ok well i got under and started checkin things out..

these parts have been changed
whole punkin with 3:73 gears
both axles
both wheel bearings
mounts on the diff its self are good
trans mount look decent..

the u joints feel tight, but the drive shaft has some play in the end of the trans.. could this be the issue?

this has been on going for a while. this is the 2nd trans that has been rebuilt in the car and it still seems to do so..

now i did read about the drive shaft. but if the trans shop put the last trans in shouldnt they know how to do it:rolleyes:. i was gonna change it but they got the bolts so tight and i didnt have the car that high in the air.:rolleyes:

looking for some suggestions.. about the trans tail.
 
Check the tires, most places only balance to 45 or 55mph and it works most of the time but they might not have been done well.
 
Subscribing. I got a braker bar and a tube with my full weight on it jumping on the axle nut in the back I was able to get maybe 3/4 of a turn out of them not sure if they backed out or what. And yeah the vibes did not go away. :mad:
 
the u joints feel tight, but the drive shaft has some play in the end of the trans.. could this be the issue?

this has been on going for a while. this is the 2nd trans that has been rebuilt in the car and it still seems to do so..

now i did read about the drive shaft. but if the trans shop put the last trans in shouldnt they know how to do it:rolleyes:. i was gonna change it but they got the bolts so tight and i didnt have the car that high in the air.:rolleyes:

looking for some suggestions.. about the trans tail.

Do you mean in and out play? Or wobble? In and out should be fine. Wobble might be a problem.

If the shop had the driveshaft out to swap the transmission, check for marks on the driveshaft and companion flange. If they didn't mark them, how would they know they installed them in the same orientation? That can easily give you a bad vibration from an out-of balance driveshaft-differential combination.

Also, tires with bad wear patterns, out of balance, or both, can give some really annoying vibes. Definitely check those.
 
Do you mean in and out play? Or wobble? In and out should be fine. Wobble might be a problem.

If the shop had the driveshaft out to swap the transmission, check for marks on the driveshaft and companion flange. If they didn't mark them, how would they know they installed them in the same orientation? That can easily give you a bad vibration from an out-of balance driveshaft-differential combination.

Also, tires with bad wear patterns, out of balance, or both, can give some really annoying vibes. Definitely check those.

i can take the drive shaft and move it say oil pan to intake up and down.

and side to side like door to door. from what they told me the case is a whole different case. but i can tell it was my tail housing. i could get a video of this but not tonight. i really think this maybe my issue.:(

another trans is in the works.. but i gotta get a job:eek:
 
ok well i got under and started checkin things out..

these parts have been changed
whole punkin with 3:73 gears
both axles
both wheel bearings
mounts on the diff its self are good
trans mount look decent..

the u joints feel tight, but the drive shaft has some play in the end of the trans.. could this be the issue?

this has been on going for a while. this is the 2nd trans that has been rebuilt in the car and it still seems to do so..

now i did read about the drive shaft. but if the trans shop put the last trans in shouldnt they know how to do it:rolleyes:. i was gonna change it but they got the bolts so tight and i didnt have the car that high in the air.:rolleyes:

looking for some suggestions.. about the trans tail.


Been there seen it and done it:eek: I chased a driveline vibration in my SC for 18 years. I started a thread in the Members Only Forum under the Drivetrain section covering my voyage to solve the vibration. After all of my trials and tribulations, a new Dynotech Engineering aluminum driveshaft finally resolved the problem.

A tire/wheel vibration is very different from a driveline vibration. The tire/wheel vibration is normally very consistent and comes/goes at a certain speed. A driveline vibration will pulsate when maintaining a speed and get worse when accelerating or decelerating.

What you are describing about the output shaft of the transmission is normal. There will be some play side to side and up and down.

Good luck.

Bryan
 
Been there seen it and done it:eek: I chased a driveline vibration in my SC for 18 years. I started a thread in the Members Only Forum under the Drivetrain section covering my voyage to solve the vibration. After all of my trials and tribulations, a new Dynotech Engineering aluminum driveshaft finally resolved the problem.

A tire/wheel vibration is very different from a driveline vibration. The tire/wheel vibration is normally very consistent and comes/goes at a certain speed. A driveline vibration will pulsate when maintaining a speed and get worse when accelerating or decelerating.

What you are describing about the output shaft of the transmission is normal. There will be some play side to side and up and down.

Good luck.

Bryan

if that is true how would it not vib from that?
 
that is a good point the tires are trashed.. :D

I have a set of wheels that use sticky weights and they are a pain to balance and only I only let certain people do it and have to constantly have to rebalance, and my vib would come in exactly as you describe. Changed the person doing the balancing and problem went away.

Those wheel need some cosmetic work so I'm running stocks now.

Plus checking the balance on the tires is cheap and easy.
 
if that is true how would it not vib from that?

All I know is both of my AOD equiped cars exhibit the same output shaft play. I think as long as the universal joints are good and the shaft is balanced then it is self-centering due to the rotation. Thats my story and I'm sticking to it:D

Bryan
 
that is a good point the tires are trashed.. :D

I have a set of wheels that use sticky weights and they are a pain to balance and only I only let certain people do it and have to constantly have to rebalance, and my vib would come in exactly as you describe. Changed the person doing the balancing and problem went away.

Those wheel need some cosmetic work so I'm running stocks now.

Plus checking the balance on the tires is cheap and easy.
 
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All I know is both of my AOD equiped cars exhibit the same output shaft play. I think as long as the universal joints are good and the shaft is balanced then it is self-centering due to the rotation. Thats my story and I'm sticking to it:D

Bryan

just didnt seem right.. if someone had cars that did this and it didnt cause an issue. then ok..;)
 
I've been dealing with the same issue. I think it is coming from the driveshaft. I am going to disconnect mine from the pumpkin, rotate it 180 degrees, reattach it and see if that helps.
 
I'd start with rebalancing all the tires. If you have larger diameter/wider aftermarket wheels you will need to take the car somewhere that has a Hunter Engineering Road Force Reaction balancer. Usually cost about $25 per wheel, but well worth it.

David
 
I'd start with rebalancing all the tires. If you have larger diameter/wider aftermarket wheels you will need to take the car somewhere that has a Hunter Engineering Road Force Reaction balancer. Usually cost about $25 per wheel, but well worth it.

David

stock wheels stock tire size. but i need new tires now that someone brought that up.

the car sat on these tires for 2 1/2 years so im sure they aint round anymore:rolleyes:
 
well figured it out i think...

clocked the drive shaft today took it down the road to 65mph and it was smooth!:D well alot better i still have a very slight vib.:rolleyes:

thought i would update..:eek:
 
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