STEEPSS

iTrader: (30)

Here's the scoop:

Just put gears in my car (9"). Re-installed the center, and it vibes like a bish

I had the short style pinion yoke, with a stock length ds. I replaced it with a long pinion yoke, and upgraded driveshaft (who i bought from "danhr" a **** eating, bottom feeding member on here.

Its a denny's nitrous ready driveshaft. When I got it, the splines in the slip yoke were twisted. SOO i replaced it with a strange chrome moly yoke and new u joint. Put it in the car, it vibrated.

Had it balanced, Still vibrated.

Put in the stock DS, still vibrated

Checked / fixed my pinion angle.... Still vibrated

I'm running out of things to blame it on.

Vibration is increasingly worse from about 45. Feels like its coming apart at 60.

HELP ME FIGURE THIS OUT PLEASE

jimbo98z

iTrader: (3)

To me the nexti logical step is to remove the 3rd member and look at it. I'd check for axle damage too.

Do you have a spare set of wheels, i.e. drag radials or something you could try?

Supers

You gotta use lots and lots and lots of detail....

Without being able to drive the car there is no way ANYONE will be even close to pointing in the right direction.

Let your local driveline shop look at the entire car

STEEPSS

iTrader: (30)

I appreciate the replies.

However, there was never any vibration before the gear / pinion yoke / slip yoke change.

So, that rules out tires, wheels, and axles.

Note: I can feel play at the slip yoke end, with the driveshaft in place. Even with the slip yoke fully pushed into the trans, I feel some play. Which leads me to believe the tailshaft bushing is worn.

IF that's the case, IDK why it would all of a sudden develop a vibration, when there is now MORE slip yoke in the trans than before!

Thoughts / opinions?

cambirdracing

iTrader: (4)

Does it vibrate when you put a side load on it? e.i. going around a bend in the road? Reason i ask is b/c I rebuilt the rear on my 94 v-d bird and put in another d/s and it still did it. Ended up being the front wheel bearings.

Lambert695

iTrader: (17)

God I hate driveline vibrations... are the yokes centered on the driveshaft and such? some u-joints dont like to center up. Also, sometimes from random vibrations that bushing in the tail housing of the trans can come off but then it usually shoots trans fluid everywhere. Did you bend anything when installing the new u-joints? Just trying to throw out ideas....

LPE 403

iTrader: (6)

Can't help asking did you go back to your original set-up in the short yoke, stock ds and start over? You'll have to 'root cause' the problem by starting at zero and sneak up on it...

Even dumber question...any chance a wheel weight fell off? Crazier things have happened.

STEEPSS

iTrader: (30)

We've had the car on a lift, and it still vibed, ruling out anything up front

U-joints are centered. The 1350 Pinion yoke has the little tabs on the end to ensure that. I was gentle in installing the u-joints, plus the stock DS also vibes

I'm gonna take the wheels off and spin it again this evening, so to eliminate this chance. It is a possibility, but it would be VERY unlikely that it just so happed to fall off once I upgraded this stuff. I have heard of guys having bigger problems with the chromoly driveshafts transmitting vibration, as compared to aluminum, but the aluminum one still has it, so I doubt that's the whole issue


Thanks for the ideas. Keep em coming and I'll try them accordingly

30th6

iTrader: (6)

i hope you find out i have the same problem.mine vibates more when i turn left and almost quits when i turn right.mine has always vib with the moser 9in,3 diferent shaft, every pinion angle known to man.im thinking about getting adjustable lcas and try to tweek it from there.

libertyforall1776

iTrader: (2)

Have you checked your Trans mount integrity?

Supers

Checking for vibrations on a lift and the driveline hanging is not going to help you...it will make it even harder...



You may very well have a problem at the rear, either a axle bearing or your carrier is about to fall out...

STEEPSS

iTrader: (30)

Good thought, I'll check it out.

First off, thanks for assuming my stupidity. I did it on a 4 post lift, with the suspension loaded.

IF it is a problem with an axle bearing, it JUST developed at the same time i put the gears in. Not saying it isn't, but it's at the bottom of the list.

30th6

iTrader: (6)

i just put new axel bearings in about 5k miles ago,and the carier is tight.any other suggestions?
sorry for the high jack been battleing this problem for about 4 years.........dam

Supers

Not assuming you are stupid, it just happens that everyday when the term lift is used, it's not a drive on, no one uses the term 4 post lift unless you are bend-pak , in the repair world when someone says lift, it was not a drive on.. so i was going on when you said lift...
That is why i gave you that reply


The turning and changing the intensity of the vibe leads me to point at the axle...
It is also very hard to pin point vibes on line... it really needs tons of detail..
You're better off seeing a local shop that has and is good in that area of expertise...or you might end up with a bill for a new car.

.Check your lugs and wheel and make sure they're not loose and or the wheel has elongated holes

.

30th6

iTrader: (6)

ive had 4 different sets of wheels....nothing changed.i would love to take it to a shop but i dont no of one around my area thats worth a dam.guess its gonna vibrate.will the rear end being tracking sideways make a vib?i aligned it after the relocation brackets and it was off just a little.i cant remember the specs but i was in the red on the screen.thanks joe

STEEPSS

iTrader: (30)

Fair enough. I checked my tranny mount, and it was a little loose, so I tightened it up. Vibration is the same. ...........

libertyforall1776

iTrader: (2)

But how is the tranny mount bushing that helps dampen vibration? Maybe it needs replacing? Or could you have a poly one already that is doing you no favors?

STEEPSS

iTrader: (30)

Its already a poly mount. I also have poly motor mounts. However, its not the problem, because it didnt vibrate at all before, and these were the same.

therobman

iTrader: (39)

sounds like the same problem im having drives fine under 40-45 but if im doing 50-60 and let off the gas it vibrates like a mother. but it only does it on the road ive tried preloading my suspension with it on a lift and it does not vibrate im working on it this weekend to see if i can fix the problem ill post up if i do

Supers

If it is off you'll track sideways a bit...

Give some more detail