crazy3rdgen

iTrader: (4)

Broke my stock driveshaft in two at the track awhile ago, so I bought a nice pst driveshaft, put it in.. and the car vibrates bad above 40mph, these come ballanced correct? What else could it really be?

thanks!

sean

AxisOfOil

may have misaligned a yoke... it could be bent.
I'd check to make sure it's installed correctly and then have the balance checked.

crazy3rdgen

iTrader: (4)

I did have to install a new universal joint myself since it came with the wrong one on the ds, pretty sure once those c-clips are clicked in, that means its in correctly right? You think the yoke on the rear could be bent?

AxisOfOil

If you hit it hard enough to snap the driveshaft... you could have bent a yoke pretty easily at the same time... especially if you were already moving when it broke (back half of driveshaft gouges pavement and shoves itself back into the yoke)

If you installed a new Universal joint, you would almost certainly have put the driveshaft off balance imo. iirc, our driveshafts get balanced as a whole unit... including the universal joint. I'm not sure at what point you can definitively say the ds is installed correctly... but i'm sure someone else will chime in with some help.

crazy3rdgen

iTrader: (4)

Bob at epp never told me that, btw this was on a launch, the driveshaft broke closer to the trans.. but did dig into some dirt as we moved it over to the shop.. Didnt think something could bend that easily? So i guess if the driveshaft looks to be installed correctly, its the yoke, dunno what else it could be.

AxisOfOil

I hope you get it all figured out man. That bites... new ds is supposed to be tons of fun! but shaking isn't fun.

I'm not really sure what it could be if it's in right, the yoke is fine, and it's balanced.
I'd just make sure everything is bolted up right, and ask bob if you would need to get it rebalanced after changing the U-joint.

And... you get this bump in case there's someone else who knows what could be going on here.

crazy3rdgen

iTrader: (4)

wow.. about to jack the car up now.. For some reason i can move the ds back and forth at the universal.. almost like the bearing cups are spread too far away from the universal joint itself, allowing it to move back and forth

crazy3rdgen

iTrader: (4)

the bearing cups need to be flush at the end correct? So is this the wrong universal joint again? Here's the gap

Elliott's94Z

iTrader: (12)

I wouldn't assume it's balanced from the get go..it may need be

AxisOfOil

if you can move it because of how the bearing cups are situated... i would assume that's bad... and any lateral movement that it allows will turn into a vibration

crazy3rdgen

iTrader: (4)

yes, so im thinking this is the wrong universal joint?

EPP

iTrader: (22)

You should not have any side to side play. By the way, swapping out a u joint is not going to significantly change the balance of the driveshaft. If it did, there would be millions of vehicles out on the road with vibration problems.
If you are using this driveshaft with the 10 bolt rear you need a Napa 447 U Joint. Bob

crazy3rdgen

iTrader: (4)

Not sure if you remember bob but this will be the 3rd time around that I need to get another universal joint. I told you before I purchased everything what I had and what this driveshaft was for. You sent me the second universal but turns out this one is wrong as well, what about sending out another that is the one I need? The reason it took so long to get on this was because I was very busy with work and college, didn't have time.

stock 10 bolt

AxisOfOil

Thx for the info Bob.

sportfan

iTrader: (1)

The ujoint caps should be inset from the pinion yoke not flush. It does not look like you have the caps compressed all the way .... my stock pinion yoke had about a 1/8" gap before the caps started.

crazy3rdgen

iTrader: (4)

This is how much play there is

Blue-Z

iTrader: (19)

Something is seriously wrong.

There should not be any play in there, either the joint is incorrect or not installed in the yoke all the way, I would guess the joint is wrong, good luck!

AxisOfOil

wow. oh wow that's quite a bit of play. I can guarantee you THAT is the biggest source of vibration you have. unless you have a baby tied to the outside of it somewhere... or something outlandish like that.

sportfan

iTrader: (1)

Wow ... Not good!!

wrd1972

iTrader: (12)

Holy loose bearing cap Batman. Sumpins bad wrong here.