Insane vibrations!

1986.5supra_kid

Rice? No its Corn (E85)
86' poopra i swapped a sc300 2jzge and r154 with 3.91 lsd into it and i had the 2 piece DS balanced and i have a ford ranger carrier cuz the yoter one shit the bed. anyways there are high frequency vibrations at highway speeds. i cannot make out what is behind me in the rearview mirror it shakes so bad. so i bought a 1piece steel with deading materal inside. guess what i still have vibrations. i asked my old man and he started ranting about flywheels,fans and transmission angles and differential pitch. so please school me on the physics of power transmission without having vibrations
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
You would have to jack up the rear of the car and start inspecting. Look at the diff mounts and make sure the pinion bearing doesn't have play.
 

Maple191

Member
Mar 21, 2012
317
0
16
Toronto
First off is actually speed depenant or is RPM depenant.
If you sit at a light and free rev in if it does it in neutral its a rotating assembly issue (Harmonic Balancer, crankshaft, flywheel, clutch/PP) If doesnt do it in neutral you may have really worn out wheel bearing or a broken mount on the diff.
 

1986.5supra_kid

Rice? No its Corn (E85)
tires and rims are year old. mostly highway miles. vibration is speed dependent say 65-75mph and throw neutral and it stays there so rotating engine assembly is out. the differential looked intact when i bolted it up in and all nuts on cv shafts are accounted for. could a wheel bearing cause that kinda problem?
thanks for the in put!
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
Usually they start making noise when they go out unless something grenaded.

Jack up wheels and push and pull for play at 12/6 o clock positions.