'81 Z28 Driveline angles / Vibration

[81LM1]

I'm Having some Vibration Issues with my z, from 3800 RPM and up. Car has brand new tires and rims, I have redone complete front end suspension,

Today, I put the car on 4 ramps and checked my angles, do these number seem correct? There are no shims under the turbo 350 Trans mount.

Transmission: 2* Downwards (checked on the Turbo 350 output shaft)
Driveshaft Angle: 3* Downward (checked on the middle of the driveshaft)
Pinion : 2* downward (checked on the pinion yoke)

What do you think? anyone have factory numbers to compare?

 

[1978 Z/28]

try this app Driveline Angle Finder. https://www.tremec.com/menu/tremec-toolbox-app/

 

[Dave Nelson]

Where is the vibration in the steering wheel or in the your seat?

 

[81LM1]

Where is the vibration in the steering wheel or in the your seat?

More so from the seat, but I do have a little vibration from the dash/ steering wheel.

Like mentioned I have a brand new front suspension along with brand new rims and tires with a alignment done

 

[dave@ztech]

Can you move the tires to a diffrent spot, front to rear rear to front, just to help eliminate the wheel balance?

 

[81LM1]

Can you move the tires to a diffrent spot, front to rear rear to front, just to help eliminate the wheel balance?

I have brought the tires back to another shop to verify the balance, I can't move the tires around because they are directional and backs are a lot wider then the fronts

 

[dave@ztech]

What type of new front suspension? Moog ? or better? If you used original parts what did you use spec wise to set the camber caster and so on? and if you replaced the front rotor bearings ? Just trying to get a better feel, of the recent mods.

 

[81LM1]

What type of new front suspension? Moog ? or better? If you used original parts what did you use spec wise to set the camber caster and so on? and if you replaced the front rotor bearings ? Just trying to get a better feel, of the recent mods.

Before all this work, I had a lot more vibration, its a lot better now but still present, suspension feels a lot more tight and handles better


New Hotchkis - coil springs / shocks
New Moog- Inner / out tie rods, center link, idler arm, Upper and lower ball joints and offset control arm cross shaft with new upper and lower control arm bushings
New Wagner Rotors, Monroe Metallic pads, Cardone Rebuilt calipers


I took the old bearings (Timken) and cleaned them in varosol and inspected them, they looked fine and packed them with grease

Alignment specs

Casters +2.5
Camber +0.1
Toe in +0.10

 

[dave@ztech]

Good parts, I am not sure about the alinement numbers as I have aftermarket upper and lower control arms, sure someone will chime in about your numbers, the rotors when remounted had no play , or now if you jack up the front and grab a tire you can not rock it side to side , everything tight? Too bad they don't use thoose old wheel balancers that when under the tire then spun it on the car, to look for or eliminate to two front wheels .

 

[81LM1]

Good parts, I am not sure about the alinement numbers as I have aftermarket upper and lower control arms, sure someone will chime in about your numbers, the rotors when remounted had no play , or now if you jack up the front and grab a tire you can not rock it side to side , everything tight? Too bad they don't use thoose old wheel balancers that when under the tire then spun it on the car, to look for or eliminate to two front wheels .

there is a little bit of thrust play in the rotors, I set tapered bearings by torqueing the nut down to 12 ft lbs then back them off one flat.
every bolt on the front end has been double checked