Vibration in motor or tranny??

[AZCOWBO]

Finally got the "Billet-T" running good, but as they say, "It is never done". The last few days I've noticed a increasing vibration as rpm increase. I first thought it was the tranny, because when it up-shifted, it would go away. Then I noticed that it went away not because of shifting, but the drop in rpms and as rpms came back up it came back with a vengeance. If I put it in neutral or park rev the engine, I don't have it. I have checked the drive-shaft and u-joints and they are tight. It has to be the tranny, I think, ha!, or maybe the engine as rpm increase under power, vs sitting still and reving it up. IDEAS!!

 

[der Spieler]

Could the driveshaft have lost a counterweight and gotten out of balance?

 

[putz]

Same idea here check the drive shaft for balance. You can jack the car up put on jack stands and spin it up making sure car is stable on stands first .You should be able to see the driveshaft vibrating if out of balance.

 

[AZCOWBO]

I had the driveshaft checked for balance before it went on and it was perfect with no counter balance weights on it. It feels more like a bearing vibration, not wavy, but constant.

 

[Duke]

May want to check the flex=plate bolts for the converter.

 

[donsrods]

Flex plate was my thoughts too. Or the converter bolts in the flexplate might be loose. My Son had a vibration in his Buick wagon and he went on line and other people were saying their torque converters were loose. Sure enough, he tightened them up and no more vibration.

Don

 

[RPM]

It is not the driveshaft at changes sped with the mph of the car not with the engine rpm. Can you unbolt the converter from the engine and just rev the motor?

 

[donsrods]

Also check your harmonic balancer. I had one slip and rotate on a 5.0 Ford engine and it acted the same way as yours. Certain rpms were ok, some were shakey.

Don

 

[AZCOWBO]

Thanks, I will check flex-plate and converter this am.

 

[Brucer]

Check pinion angle.. Seems like you said under acceleration or deceleration, but not when sitting still

 

[Screaming Metal]

RPM is on the button!!!!!!

OK.......raise your car......block it up safely, pull your converter bolts and slide your converter toward the trans pump. Put somewire thru the bolt holes and tie it back so the flexplate can't hit it.

Now......start the engine and rev it and see how it acts.........if theres no vibes...........it isn't your engine,,,,,,,,,,

Now hook your converter back up and rev it with your engine in neuteral or park..............no vibe...........look after your mainshaft in your trans.......possibly yokes, ujoints, driveshafts, etc...........