7004r vibration

[VIN7]

This is in my daily driver 90' GMC S15 with 4.3. Around 1300 rpm there is a very bad vibration which goes away around 1700 rpm. It does it in park as well as in gear. I just had the torque converter replaced and it didn't help. I removed the serp belt and the vibration is still there. Someone suggested that it is common with the 7004r trannies to vibrate at that rpm range. Any tranny guys experience this? If so, is there a fix.

Thanks,
Mike

 

[chris718]

diagnosis of driveline vibrations can be extremely complicated even for a seasoned technician .HERE ARE SOME THINGS THAT WILL SIMPLIFY THIS .disconnect the convertor from the flywheel,pull it back and start the engine .is the vibration still there ? if it is not suspect a bent input shaft ,worn stator shaft bushings,trans mount ,loose crossmember.etc.Ifit is still there suspect a cracked flywheel,damaged vibration damper,loose or broke motor mounts ,grounded trans lines or grounded exhaust system .grounded means touching something.this info is based on what you have posted .i have seen this before with any one of these things being the cause. lets here what you find ckperformance.com