High Speed Vibration... I need a checklist!
11-22-2008, 04:55 PM
#1
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
High Speed Vibration... I need a list of all possiblities... Ok, i balanced all 4 tires, had the steel driveshaft balanced. still there...
it really does feel like the driveshaft, and it happens around 75-80mph and gets really bad at around 95-100 mph. i can feel it in the seat and its a loud noise. it feels like the driveshaft.
so i put an alum driveshaft out of an LS1 car into it. It got better, but the vibration is definitely still there.
I would like to know a checklist of things i should look at on Monday when i go back to work and have access to heat and a lift
I have read up on things and people say check pinion angle and such, but what numbers am I looking for?
Its a 96 ws6, with SFCs, trailing arms, and i put an eaton trutrac in the rear when my spider gears blew out. So Im thinking maybe a backlash issue in the rear? would this cause it. I also have a whine coming out of the rear with the car in gear going about 55-65. it goes away with the clutch pedal in, and it also goes away in neutral obviously...
it really does feel like the driveshaft, and it happens around 75-80mph and gets really bad at around 95-100 mph. i can feel it in the seat and its a loud noise. it feels like the driveshaft.
so i put an alum driveshaft out of an LS1 car into it. It got better, but the vibration is definitely still there.
I would like to know a checklist of things i should look at on Monday when i go back to work and have access to heat and a lift
I have read up on things and people say check pinion angle and such, but what numbers am I looking for?
Its a 96 ws6, with SFCs, trailing arms, and i put an eaton trutrac in the rear when my spider gears blew out. So Im thinking maybe a backlash issue in the rear? would this cause it. I also have a whine coming out of the rear with the car in gear going about 55-65. it goes away with the clutch pedal in, and it also goes away in neutral obviously...
Last edited by ThoR294; 11-22-2008 at 05:40 PM.
11-22-2008, 08:55 PM
#2
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
anyone have an idea? I have heard its something to do with the tail shaft in the transmission, but this trans was a rebuilt unit with only say 2k miles on it right now...
11-22-2008, 10:38 PM
#6
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
haha. Its so bad. It feels like the driveshaft is just going to spin off. Ive read things that it is something inside the trans... i really hope it is not
Trending Topics
11-23-2008, 11:42 AM
#8
TECH Regular
iTrader: (9)
Join Date: Mar 2007
Location: Hellertown, PA
Posts: 409
Likes: 0
Received 0 Likes
on
0 Posts
Ok, i balanced all 4 tires, had the steel driveshaft balanced. still there...
it really does feel like the driveshaft, and it happens around 75-80mph and gets really bad at around 95-100 mph. i can feel it in the seat and its a loud noise. it feels like the driveshaft.
so i put an alum driveshaft out of an LS1 car into it. It got better, but the vibration is definitely still there.
I would like to know a checklist of things i should look at on Monday when i go back to work and have access to heat and a lift
I have read up on things and people say check pinion angle and such, but what numbers am I looking for?
Its a 96 ws6, with SFCs, trailing arms, and i put an eaton trutrac in the rear when my spider gears blew out. So Im thinking maybe a backlash issue in the rear? would this cause it. I also have a whine coming out of the rear with the car in gear going about 55-65. it goes away with the clutch pedal in, and it also goes away in neutral obviously...
it really does feel like the driveshaft, and it happens around 75-80mph and gets really bad at around 95-100 mph. i can feel it in the seat and its a loud noise. it feels like the driveshaft.
so i put an alum driveshaft out of an LS1 car into it. It got better, but the vibration is definitely still there.
I would like to know a checklist of things i should look at on Monday when i go back to work and have access to heat and a lift
I have read up on things and people say check pinion angle and such, but what numbers am I looking for?
Its a 96 ws6, with SFCs, trailing arms, and i put an eaton trutrac in the rear when my spider gears blew out. So Im thinking maybe a backlash issue in the rear? would this cause it. I also have a whine coming out of the rear with the car in gear going about 55-65. it goes away with the clutch pedal in, and it also goes away in neutral obviously...
i am having almost the same problem around 80 mph i get this real bad shaking but its more of a harmonic vibration then a tire vibration i had my chromoly strange driveshaft shipped back to have them check the ballancing hopfully thats what it is
11-23-2008, 11:53 AM
#9
Heres from a recent thread
Some other easy checks are the driveshaft yoke at the transmission, see if you can move it up and down with it in neutral, if it moves a lot it could be the bushing.
Check to be sure the pinion at the rear is tight. I solved a vibration at 110 mph by changing the rear yoke, I actually put the original one back on, I swapped it when I did gears.
That and all the other things mentioned already.
The T56 mainshaft tends to get worn at the spot where the 5-6 driven gear is pressed on. Simply put, it is a bad design from the factory. The gear starts moving back and forth as it loses its press fit. Then it wears the splines down. From that point it gets progressively worse. I've been running into this more and more with the rebuilds that I do. There is a fix that I offer. I get the mainshaft re-machined to .005" thicker than stock so the gear presses on a lot tigher, and this eliminates the problem. I wouldn't have thought that this would cure a driveline vibration until I "accidently" fixed a vibration in a customer's car. He had been chasing the vibration issue for 2 years and pretty much gave up. While rebuilding his tranny I noticed the mainshaft was worn, so I had it re-machined. At this point I did not know he even had a vibration. After he got his car back he called to tell me his vibration was gone. I'll have to post up some pics soon so its easier to understand. Anyway, I offer this service for $100 exchange. You just have to send in your mainshaft.
Check to be sure the pinion at the rear is tight. I solved a vibration at 110 mph by changing the rear yoke, I actually put the original one back on, I swapped it when I did gears.
That and all the other things mentioned already.
11-23-2008, 06:04 PM
#10
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
Heres from a recent thread
Some other easy checks are the driveshaft yoke at the transmission, see if you can move it up and down with it in neutral, if it moves a lot it could be the bushing.
Check to be sure the pinion at the rear is tight. I solved a vibration at 110 mph by changing the rear yoke, I actually put the original one back on, I swapped it when I did gears.
That and all the other things mentioned already.
Some other easy checks are the driveshaft yoke at the transmission, see if you can move it up and down with it in neutral, if it moves a lot it could be the bushing.
Check to be sure the pinion at the rear is tight. I solved a vibration at 110 mph by changing the rear yoke, I actually put the original one back on, I swapped it when I did gears.
That and all the other things mentioned already.
Im going to put my car on a lift tomorrow at work, and Im going to check everything. I will definitely check the driveshaft yoke.
I saw that quote from the other thread, but I am kinda confused on why it would cause this ridiculous vibration. It is really really bad...
11-23-2008, 10:25 PM
#12
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
i really do not think the driveshaft is a problem. I have my stock steel one that was balanced with 2 new U joints, and another alum shaft with a new rear U joint out of a 99 camaro.
or am i looking at the yolk for wear due to the bushing maybe being bad?
UGH! im so anxious to look at it! i cant wait
or am i looking at the yolk for wear due to the bushing maybe being bad?
UGH! im so anxious to look at it! i cant wait
Last edited by ThoR294; 11-23-2008 at 10:51 PM.
11-23-2008, 11:06 PM
#13
The yoke and the bushing both wear. It's less common to have the yoke wear, I've only seen it on stuff with over 200,000 miles.
The bushing might be worn.
It's actually more difficult to change the bushing than to change the yoke.
The bushing might be worn.
It's actually more difficult to change the bushing than to change the yoke.
11-24-2008, 05:55 PM
#14
TECH Addict
Thread Starter
iTrader: (6)
Join Date: Jul 2007
Location: Ringoes/Flemington, New Jersey
Posts: 2,858
Likes: 0
Received 3 Likes
on
2 Posts
yaaaaaaaaaaaaaaaaaa so im stupid. I probably shoulda did this earlier... but I finally got my buddy to drive my car while it was on a lift... and the ****** right rear wheel wobbled so bad.
So I pulled the wheel off and did a rim runout test on the tire balance machine. Sure enough.... the inside of the rim had .031" runout.
lol. good game... BAD RIM!
So I pulled the wheel off and did a rim runout test on the tire balance machine. Sure enough.... the inside of the rim had .031" runout.
lol. good game... BAD RIM!
11-24-2008, 06:09 PM
#15
TECH Fanatic
iTrader: (4)
Join Date: Feb 2008
Location: S.W. Missouri
Posts: 1,291
Likes: 0
Received 0 Likes
on
0 Posts
yaaaaaaaaaaaaaaaaaa so im stupid. I probably shoulda did this earlier... but I finally got my buddy to drive my car while it was on a lift... and the ****** right rear wheel wobbled so bad.
So I pulled the wheel off and did a rim runout test on the tire balance machine. Sure enough.... the inside of the rim had .031" runout.
lol. good game... BAD RIM!
So I pulled the wheel off and did a rim runout test on the tire balance machine. Sure enough.... the inside of the rim had .031" runout.
lol. good game... BAD RIM!
11-25-2008, 11:17 AM
#16
04-28-2009, 08:40 PM
#17
Teching In
Join Date: Jan 2008
Location: Yardville, NJ
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
i have an lt1 and t56 in my 86 regal. same thing. At about 80 mph in 6th i start to get a low vibe that seems to increase. if i downshift to fifth and speed up then let off the gas the vibe is real bad, like when the gears mesh on the coast side it is causing some imbalance. Just had the damn thing apart to and didn't think to replace the bushing so..........eh........ Keep us updated.
Mike
Mike
05-08-2009, 12:41 PM
#18
Teching In
Join Date: Jan 2008
Location: Yardville, NJ
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
I was reading up on a few things and found out something that might help someone out. Apparently, the main shaft could be the problem where the 5/6 drive gear is located. When i pulled my trans apart the gear slid off whereas it is supposed to be a press fit. This might have something to do with your problem. I am going to look into buying a crossmember instead of using the one i made and am going to swap wheels front to back to see if that helps my vibration. I don't really wanna pull this pig back apart.
