Vibration problem driving me nuts!
Thread Starter
|
New User
Joined: Aug 2006
Posts: 6
Likes: 0
Vibration problem driving me nuts!
I swapped a newer 400 into my '78 F-250 and now have a vibration that I haven't been able to get rid of.
I can notice it at idle, but it's really bad when I am in a high (3rd) gear at low RPM, particularly climbing a hill. I get a lot of kicking in the accelerator pedal and a really hard vibration from the engine/tranny area.
I put a new flex plate in when I put the engine in. I have replaced the motor and tranny mounts. Put new torque converter nuts on. Replaced the U-Joints (shouldn't have an effect, since I can feel it at idle). Put new plugs, wires, cap and rotor in. New MSD ignition. Plugs gapped to MSD specs.
It's driving me nuts. Any ideas as to how to troubleshoot or if anyone has run into this problem before, advice would be greatly appreciated.
I can notice it at idle, but it's really bad when I am in a high (3rd) gear at low RPM, particularly climbing a hill. I get a lot of kicking in the accelerator pedal and a really hard vibration from the engine/tranny area.
I put a new flex plate in when I put the engine in. I have replaced the motor and tranny mounts. Put new torque converter nuts on. Replaced the U-Joints (shouldn't have an effect, since I can feel it at idle). Put new plugs, wires, cap and rotor in. New MSD ignition. Plugs gapped to MSD specs.
It's driving me nuts. Any ideas as to how to troubleshoot or if anyone has run into this problem before, advice would be greatly appreciated.
Post Fiend
Joined: Jul 2006
Posts: 6,948
Likes: 44
Have you installed the correct external balance flexplate on this engine?
If it vibrates at idle either the wrong flexplate has been installed, or the harmonic balancer is wrong or bad. Have seen on more than one occasion the balancer beginning to seperate and causing terrible vibrations.
If it vibrates at idle either the wrong flexplate has been installed, or the harmonic balancer is wrong or bad. Have seen on more than one occasion the balancer beginning to seperate and causing terrible vibrations.
Postmaster
Joined: Aug 2000
Posts: 3,312
Likes: 1
From: Eldorado Ca. USA
Originally Posted by huntingnt
I can watch the balancer and it seems to track straight (no visual wobble). The flex plate has weights welded to it. Is that externally balanced?
