1986 Pickup Vibration while driving and in neutral

[skidoo911]

Im looking for some help weather some thinks I have a tourque converter issue or u joint issue. It idols smooth. When i rev it up it vibrates. its at its worst about 80kms or 50mph. its an easy fix to replace u joints. Changed the ballancer on the front to no success. Let me know your thoughts.

[skidoo911]

anyone have any ideas?

[2018GMC]

Check your motor mounts and transmission mount to see if they are torn. Does the entire cab vibrate? Just the steering wheel?

 

Are you sure it is and engine vibration and not the wheels / tires?

[skidoo911]

I put a different sent of rims and tires on and it never changed. I haven't checked the mounts. I can fell it through out the truck.

[Squirrely]

I vibrates when sitting still?

[skidoo911]

it idols perfect and you cant feel anything. The engine doesnt miss.

[Squirrely]

my guess is u-joints then. If it only vibrates when the truck is rolling.

[matt123]

It does it reved up in neutral? That rules out ujoints.

 

What engine? is this a new problem?

 

Warped or cracked flexplate/flywheel?

[skidoo911]

It does vibrate when I rev it up. Thats why I thought possibiIy the torque converter. I have checked the flex plate and cant see any cracks. Its a 305 and I bought this truck thinking it was likely the tires.

[matt123]

You can undo the 3 or six bolts that hold the flex plate and torque coverter together, then wiggle the torque converter and you should be able to slip it back at least half an inch or more, then start the truck and rev it. That way you can rule out the converter.

 

Was your old balancer bad or you just replace it to see if it would help?

 

Maybe you have a ignition problem or fuel supply problem. I'm not much help with carbd trucks. Maybe replace the fuel filter, likely time for it anyways. check cap and rotor and timing?

[Squirrely]

Check harmonic balancer?

[txab]

Check harmonic balancer?

Op said he changed it already

[txab]

Check your motor mounts and transmission mount to see if they are torn. Does the entire cab vibrate? Just the steering wheel?

 

Are you sure it is and engine vibration and not the wheels / tires?

+1

[Squirrely]

Just to throw this out there. I had a hub go bad and it would vibrate like crazy. And it was loud.