Driveline Vibration after motor swap, need expert help.

Guys, I'm at a loss. Tried everything, about to send it off and get someone else to do it, but I like to do things myself.

Car:
1964 Galaxie. Had a 352. No issues, drove smooth. No vibrations.

Engine:
460 with C6 came from a 1977 Ford F-150. Truck drove fine, no issues, no vibrations.

Put complete motor and trans from truck into Galaxie. Got mounts from Dearborn Classics, made my own trans crossmember out of 3/16" wall boxed tube. Used stock driveshaft with the yoke from the truck and Spicer conversion u-joint to join them (1310 series to 1330).

Vibration Description:
Low pitch intermitent hum or rumble starting at about 55mph. As speed increases the duration of the rumble gets longer...i.e from brrr-brrr-brrr to brrrrrrrrr-brrrrrrrr-brrrrrrrr.

What I've done trying to fix it.

Have the Driveshaft Balanced and new u-joints $80. Driveshaft shop said it was out of balance and corrected it, but once put on car it made no difference.

Lenthen driveshaft 1" $125. Did this to better contact the tailshaft pilot bushing since it wasn't exactly the right size and I thought that this could be an issue. Made no difference.

Installed Pinion Angle Shims $40. I got in depth on driveline harmonics and determined that the new motor placement was a couple of degrees off stock so I added shims to bring the pinion angle in parallel with the transmission output shaft. This affected the vibration but only made the duration of the rumble shorter and quicker brr-brr-brr-brr-brr.

I would suspect the differential if I hadn't driven the car and knew that it was fine before the motor swap, so I know it must be something with the driveshaft or motor placement?

What if any suggestions do you seasoned hotrod builders have for me?

 

Did you install a new transmission mount? HRP

 

Pull the driveshaft and reinstall with it turned 180 degress from where it is now.

 

Brand new Transmission mount, and I have also tried the 180 degree flip trick. Thanks for the replies, keep em coming.

 

I'm confused. So the driveshaft shop was unable to completely balance the driveshaft???

 

Driveshaft shop confirmed it was out of balance, corrected it, but made no difference. Sorry for the confusion. Driveshaft is balanced.

 

Are you sure all the nuts and bolts are tight?HRP

 

Yes sir, I'm OCD about those things.

 

Also, I have run it in the air on jackstands and the vibration is present. So suspension and alignment isn't a factor... it's cleary happening between the trans and rearend.

 

Check your slip yoke . I have a buddy that had a similar issue . Turn out his yoke was out of round .

 

Double check the motor mounts and transmission mount to see if there is metal to metal contact someplace. Also check exhaust system to see if it is touching the body or frame somewhere. Is the trans. or engine touching the frame or trans. tunnel?

 

Did you replace the slip yoke bushing in the tail shaft. Tons of info on driveline angles. Start with the 101 course check all the fundamentals before loosing your mind. Get a good angle gague.

 

Check bellhousing bolts to make sure they are tight. Had a friend fight this for a year before he found it.

 

Tests where done with open pipes, so no exaust to touch anything.

I'm interested in the question about mounts. Would an engine create such a vibration under normal cruising conditions that could be tranferred to the frame? The mounts had a bolt running through them to keep the motor from ripping the rubber apart. Has anyone used the solid mounts sold these days? Do these create such a vibration?

 

Might also check if you have an angle side to side. Check the location of the crank snout to car centerline against the trans output to centerline. If the engine/trans isn't square to the car it will be similar to the pinion angle being off. Engines aren't always centered in the car, but they need to be parallel to the centerline.

 

I checked them when the motor was out, but will confirm. Thanks

 

Great suggestions, only reason I don't think it's that is because the engine and trans ran great when in the truck.

 

Raise rear transmission mount (shim), if it's worse go the other way, if it's better keep going (within reason)

 

My friend has a 55 sedan delivery on a Morrison chassis and a 502 Ramjet that he originally mounted with urethane mounts - lotsa transmitted vibrations - switched to "stock" rubber mounts and they went away.

 

I had thought about that too. I will check that this weekend. I see some plumb bobs and chalk lines in my future.

 

Open exhaust? Are you sure it is not a vibration being caused by the Open exhaust creating a Harmonic or Sympathetic vibration?

 

Great info, thanks. I'll consider this after checking that everything is square side to side as previously mentioned.

 

The only thing not previously proven to be good and running vibration free before the swap in either the truck or galaxy is the spicer conversion u joint - is that correct ?

 

I'm absoletely sure its in the driveline, it's hard to describe in words, but you would know it if you were touching the car.

 

Yes sir, that's the only oddball peice. But it was sent to the balancer installed, and everything balanced as an assembly, so I assume it is ok.

 

I would have never thought of this, Vibration may be due to worn shocks, also check the trany fluid lvl

 

Why not post some pictures of the driveshaft ,some of the crossmember and mount setup and the motor mounts.You did say you made changes on all three so one or more is causing your vibration.

 

Having read what you describe about your vibration, often overlooked, the pinion bearings. You have a 64 Galaxie with a 9" differential made for the 352. Now you've put a ton more power to it. It's possible you've broken the webbing that holds the back pinion bearing in the third member.
I had a 300-6 automatic break the webbing on a 9" Ford, it did the same brrrrbrrrr brrrr oscillation you feel.
Anytime I feel the brrrrrbrrrrr oscillation I look for something going round and round like bearings. Check wheel bearings and carrier bearings while you are checking things.

 

Am I reading it right that you have solid motor mounts? They will definitely add vibrations to your car!

 

Remove the modified motor mounts with the bolt through them and use stock or safety interlock mounts.