ok so this whole calamity started about a month ago when i was putting a clutch and flywheel on my car. i had the driveshaft in the tranny turning it to line the splines up and i let go of it and it dropped feet and fell right on the u joints. now im pissed and i have a vibration. so i order a new drifveshaft from mazdatrix put it in and things were gravy. a week later i ordered some compition diff mounts from mazdatrix cause mine were shot and i wanted to replace them. i put them in and go for a drive i nail it in 2nd and at about 4500 or so i get a crazy vibration that feels like its comeing from right beside the tranny. so i figued i might not have all the bolt really tight but they were fine so now im here and not very happy.

 

check the drive shaft again where it hooks up to the diff in the back...the mounts themself being that there compition might play a roll in the vibration...but from reading your post something has to be lose...good luck bro

 

process of elimination man. start making sure everything is tight from the back of the driveshaft all the way to your new flywheel. at least thats what i would do.

 

yeah but it only vibrates in second or first. wont do it all the time like with a drive shaft related issue.

 

could this possibly just be clutch chatter?
did u use a light weight flywheel?
another thing u can try to eliminate the vibration is to slighty lift the tranny before tightening the bolts on the front end of the ppf. if u noticed the bolt holes @ the front end are slotted so there is a little room for adjustment there. some might say this is only for the ease of installation but i have been told different. possibly worth a shot.

 

counter weight?

 

got found it. its was the PPF like smitter113fd said. the trans wasnt at the right location. so took a impact a and a stiff knee and no more vibration!

 

Its possible that the bolts are not tight. Did you put some bolt tightener around the bolts? Always torque the bolts according to factory specs.

 

yeah loctite and torqued