driveshaft vibration

[tayzoid1]

in my old car there is a bad vibration in 5th gear right about 2300rpm and above the faster you go the more violent it gets it only happened after the new t-5 nothing was changed with the drivshaft i have not ckeacked the ujoint but i really dont know what im looking for in the ujoint's should riot(jason) have the driveshaft balanced or just u joints im kinda lost
thanks
taylor

[86GTPONY]

Trying to remember - did you just do an auto to 5-speed conversion? Either way, first make sure your driveshaft bolts are tight. Your yokes should be neither stiff, nor sloppy. If all is good there, I can't see an imballanced driveshaft being that violent.

[LeeH]

in my old car there is a bad vibration in 5th gear right about 2300rpm and above the faster you go the more violent it gets it only happened after the new t-5 nothing was changed with the drivshaft i have not ckeacked the ujoint but i really dont know what im looking for in the ujoint's should riot(jason) have the driveshaft balanced or just u joints im kinda lost
thanks
taylor

It could be a pilot bearing problem or the mainshaft has excessive play in it from it either being impropperly shimmed or bad bearings. I know all the T5s I have seen with bearing problems have had major vibration issues in 5th gear.

[QWKSNKE]

The balance marks are not lined up. There should be a paint mark on the pinion flange and one on the d/shaft. If you still have a stock d/shaft the marking will be yellow. If you have the FMS aluminum shaft, it will be purple I think. Rotate the shaft until these marks line up

[qkjuicedpony]

Rotate the shaft :ymca::ymca::ymca::ymca:






:jester:

[tayzoid1]

lol at qckjuiced
but ne way no it has always been a 5speed somone told me to rotate the driveshaft 90 degrees util it stops but i havent had the time so i just posted it i will try it today and see if it works and yes lee it has the factory drive shafts but it also has the factory ujoint thats why i thought it could be them but when i am checking the u joints what am i looking for when looking for a bad u joint?

[SlowJoe]

on my 87 t-bird i had the same thing going on. pulled the drive shaft a few times and could not tell it had a bad u joint. so i just bought 2 new ones and when i pulled it apart the front u joint had about half the bearings missing in one of the caps. problem fixed.

but if it just started with a trans swap i would look there. is it a v8 5 speed?

[tayzoid1]

yea v8 5spd i have put two other trannies in it that were in alot worsh condition then this one so i dont think it is this one im gonna rotate the shaft and see if that is it then the ujoints and then i guess ill see it is the same transmission that i got from coupe so i dont think it is the tranny i dealt w/ coupe alot and he is a very honest guy so i dont think he sold me abad tranny

[EHardy1971]

Does it still have the dogbone on the rear end?

[QWKSNKE]

If the yellow marks are not lined up it will vibrate. The driveshafts mount a certain way to the pinion flange. Crawl under the car and line these marks back up and it will be as good as it is going to get

[BAD INT]

like everyone says make sure the shaft is clocked to the correct position and I can believe you arent having vibe issues in any other gear there is usually some.

Eric do you leave the dog bone on yours ? if the stock gear has been changed I usually remove mine

[EHardy1971]

Eric do you leave the dog bone on yours ? if the stock gear has been changed I usually remove mine
Yeah,I left mine on.Even though my driveshaft is clocked correctly,it will still get a slight vibration and hum above 65 mph without it.

[tayzoid1]

i cant find any yellow marks at all no marks at all i just rotated it one bolt hole to day and drove it still a vibration was gonna do one more bolt hole but then something came up and couldnt get back to it today but yea as i said i cant find any marks anywhere near the pinion

[QWKSNKE]

i cant find any yellow marks at all no marks at all i just rotated it one bolt hole to day and drove it still a vibration was gonna do one more bolt hole but then something came up and couldnt get back to it today but yea as i said i cant find any marks anywhere near the pinion

you will have to look closely in good light. More than likely the rust is covering up most of the mark. They are there, trust me

[qkjuicedpony]

The marks dont just go away.

Try cleaning everything with brake cleaner

[tayzoid1]

ok will do i just rotated it compleatly 180 of what it was and still vibrating but i have looked this thing over and i cant find any mark but i will try cleaning w/ brake cleaner and post the results and another question ujpoints wouldnt make it vibrate real bad would it? cause i cant feel any slack exept the transmission slightly rotating in gear but it is almost nothing

[EHardy1971]

Yes,a bad u joint could cause vibration,but you said it's only doing it in 5th gear,right?

[tayzoid1]

yea only really bad in 5th at 2400 rpm it is doing it a lil in the other gears but its hardly noticable

[EHardy1971]

Just for grins,have you checked it for any dents/dings? I'm with Qwksnke,and Qkjuiced on checking it to see if it's clocked properly,but just trying to think of other possible problems.

[tayzoid1]

i havent cheacked really close but now that you say something that very well might be it