vibrations after more lift?

[ryna]

hey everyone

I just put on my 2" springs onto my already spoa car. Sits and rides alot better, firmer but good flex.

The only thing is when i drove it, it vibrated quite a bit, then a while down the road it went clunk, and now its only vibrating when i hit 4th gear.

The rear tailshaft popped out while i was messing with the axle, but its all in fine now, but its obviously on more of an angle.

Is it just unbalanced?

[christover1]

possibly the uni joints aren't "worn in" to the new driveline angle.
It may pass with time and lube, but new unis may be the answer.

christover

[bozwon]

it could be your tailshaft. did u put the axle back in exactly as it came out (i.e the yokes are on the same angle/axis) if they are not then you may/will get some vibration. however some (very few that ive seen) tailshafts have yokes which do not line up but still give no vibration.
we have had stuff come into work with tailshaft vibrations and it allways seams 2 b balence or timing.

your new tailshaft angles could be the problem.
uni joints are not supposed 2 work past 14 degrees. its simply 2 much angle 4 them 2 rotate freely. if the angle is greater than this then they bind up a bit. which causes vibration.

and possibly your unis are stuffed and need replacing.

or it could be something else entirley but probly not

hope this helps

[BlueRidgeRunner]

Sounds like your pinion angle may be too low.

[lay80n]

When you did your SPOA did you rotate the rear diff slightly to point the pinion up a bit. Sounds like either your unis are working through too much of an angle, or when your tailshaft was pulled apart it was not put back together properly. Just wondering why you chose to fit lifted springs to a spoa, what size tyres you trying to clear??
Layto....

[ryna]

i didnt put the tailshaft back in in exactly the same position, how can i figure out where it was (i didnt intend to pull it out, so i didnt make marks on it. Why does it go in a certain place, ive heard ppl say it before, but i always wonder why, if its just a round spline.

Im only clearing 32's but stock springs were inverted pretty badly, and i have a low spoa. its sits almost same height as it did when i did the spoa, just a tiny bit higher.

[NUGGS]

There should be some factory marks. One one the very end of the drive shaft/spline (looking directly onto the end) and you have to take the little rubber booty off to initially find the one on the yoke or whatever it is called.( where the spline sticks in)

[ryna]

its a lengthened tailshaft, not the standard one.

Still whats the reason for it going in a certain way? Im curious now

[JrZook]

The reason for it going back together a certain way is because the shaft was balanced a certain way. ie have you noticed balance weights on it? If its not put back together the same way you will have a heavy spot causing a bad vibration.

[christover1]

both uni joints need to be lined up exactly.
ie yokes in same position as each other.
If not, the cause huge vibes, as a uni isnt a smooth spin, and both spins need to be identical.

christover

[lay80n]

both uni joints need to be lined up exactly.
ie yokes in same position as each other.
If not, the cause huge vibes, as a uni isnt a smooth spin, and both spins need to be identical.

christover

As christover said, the uni joint accelerates and decellerates twice during a 360 degree rotation. Using 2 uni joints balances this out, allowing a tailshaft to spin 'smoothly'. If your uni joints are out of phase with each other, they will create mega vibrations. Also you should always mark your tailshaft to flange location when removing shafts, as it is also possible to get vibrations from this too. If your still curious shoot me a PM and i can send you some diagrams and stuff bout it.
Layto....