I'm hoping someone can give me some ideas here... this one's got me stumped. I have a '63 Fairlane Wagon, 260 V-8, originally had the BW T85 w/OD three on the tree. It has the original Ford 8" rear with original 3.80 gears. When I first got the car, driving it "as is", it had a vibration problem... well... it had multiple problems as it turns out. But the one I haven't been able to fix is this: The car had/has a fast oscillation vibration that's often times inconsistent (sometimes there, sometimes not there) at different speeds... except over 70 MPH where it's always consistently there. At 45 MPH it's often there... more often than other speeds... but still not all the time. I can push in the clutch and let the engine RPMs drop to idle, and it has no effect on the vibration. Now here's the part that's got me pulling my hair out... since then, I've done all of the following: - New (not rebuilt) T5, moving the shifter to the floor, mounted to the 260 via Quicktime bellhousing, with custom crossmember (modified original) using original trans mount - New RAM clutch, new flywheel, new throwout bearing and hydraulic pedal setup - New driveshaft with new U-joints, built, assembled and balanced by Inland Empire Driveline - New tires all the way around, mounted and balanced on the original 14" wheels - New Yukon rear axles, both sides, new Timken bearings - New Detroit leaf springs, all new bushings, new shocks all around - Adjusted pinion angle to match (just shy... less than 1 degree) of being parallel with the trans output shaft .....and I STILL have the vibration! WTF?? What else could it be possibly be? As I said, I can drop the engine to idle with no effect, so it's not the engine. Could the third member possibly cause a vibration like this? It doesn't howl, gears look good, pinon is tight, and I just changed out the oil in it. I've also tried multiple pinion angles... up to a 3 degree difference (to allow the rear to rise under acceleration), and it made no difference good or bad. I don't know what else to try... anyone have any ideas what I might be missing? Thanks!
Brake drum out of balance? But that doesn't explain being intermittent problem. My dad had a vibration and turned out the park brake was dragging just a little causing a vibration.
try changing tires and rims out . the web ( center ) of the rim can be bent out of shape from over the years , you can check this out by putting it on a spin balancer and slowly rotating it by hand and watching , it doesn't take much to do it the rim should be straight and true with no side wobbles also a bad lughole not seating flat on a brake drum or rotor can do this , I doubt its the third member or the driveshaft (IE builds good stuff) also check your U joints to make sure they are seated properly in the saddles as that can do it also . and use a torque wrench when tightening them u joint bolts ! you can over torque the caps and flatten the needle bearings and that can make a balance issue , but it will ussually make a noise too ..
I have has the sameish issue with needle bearings not all being in the U-joint, or one falling over and the knob just put it together anyway.
Had a similar issue with my Fairlane, 63, Check the drive shaft yolk and see how far out of the transmission the yolk is sticking. If you see more than about an inch of shinny yolk that is your problem. While the factory yolk is about 7 inches long only about half of it is splined.
Look harder at the pinion bearings in the rear end. The early 8" had issues with these, and if they're going bad you can get a vibration. Had just this issue on a '64 Comet, replacing the pumpkin cured the problem.
Since everything in the drivetrain has been replaced with no change, except the third member, the hubs/brakes, and wheels, it seems I'd look at the third member, the hubs/brakes, and the wheels. I always look for scrapes and rust as signs of something out of whack. Do you have a dial indicator to check hubs and wheels for runout? If nothing obvious, then start taking apart the easiest things. Still nothing obvious, then start replacing the cheapest things.
Bumper to bumper in no particular order of probability and not mentioned... 1.Harmonic Balancer... is it in good shape and is it correct? 2. Thrust bearings...bad thrust bearings will cause a small block Ford to do strange things. 3. Flywheel... Is it in correct balance/imbalance for the engine? Is it a correct mate for the front balancer? 4. Motor and transmission mounts 5. Shackles 6. Shackle mounts 7. Rear uni body/rear subframe interface....In good condition? Any damage rust, poor repair? 8. Front tourque box to front suspension....same comments as 7
Thanks all... this has given me some great ideas! I can try the rims by swapping front to back to see if anything changes (wouldn't go away, but should certainly feel different). I can't imagine that wouldn't have already happened, given how many times the wheels have been off... but one never knows! I can also put the back up on jacks and pull the wheels AND drums off, then run it up to vibration speeds and see what I get... rule out the drums out of balance... and the wheels, for that matter. And I'll definitely give a closer look at the pinion bearings and the other items mentioned here. It's got to be one of these!
If you have lowered the car, or altered the engine/trans sitting angle, or altered the rear suspension/pinion angle; watch this:
run it on jack stands (rear) and see if anything obviously bend, vibrating. If not, problem is in front. With driveshaft turning, see if runout in front or rear of d/s
If you lowered the back of the trans to get it under the floor support,you need to trim/remove the support and get the trans up higher!! We had a similar issue on a customer car with a T-5 transplant,he did not believe us,took it to another shop,they told him the same thing.They trimmed the support,redid the mount to raise the tail,vibration was gone!! ROY.
I had the same problem at 70 mph. One Rear Brake Drum was cast off-center/out of round. Had the drums turned also, and even though brand new, they were all bad.
Grab your driveshaft in your hand, try to move it up or down or side to side... any play in it will tell you right there is the issue.
I had a similar problem on a "68" Camaro. After replacing and balancing pieces it turned out the problem was as simple as replacing the pilot bushing.
I vote pinion angle issue--gets you every time 1 degree nah...NAPA chassis catalog for trucks and 4wd has pinion adjustment shims like a cheese wedge goes between rear pad and spring--cheap and effective avaivable in 2, 3, 4, degree etc and you can use in either direction--I do not think it is right--had similar issues myself--also agree get that yoke up in the back of that trans all the way--pull it back one inch and there is where it needs to be shaft length wise
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