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4/05/2013 2:23 AM  #1


1964 Falcon Sprint HT Vibration Issue

So I have a 1964 Falcon Sprint HT. I bought it in November 2012 and drive it daily. It has an original Warner T-10 four speed with power steering and A/C. The 260 had been replaced with a 289 from a Fairlane. It also appears to have a post 67 pumpkin, 8 in rear open diff with 3.25 gears and traction bars.

Here is a list of things I've done to the car since acquiring it:
-Replaced 14" Magnum 500 wheels with 15" American Racing Torque Thrusts running Pirelli 205/60 tires (think I'm gonna switch to Radial T/As. Pirellis came with the wheels from a friend who put less than a 1000 miles on them with his 66 Mustang before switching to 17" wheels.)
-Replaced V8 front drums and spindles with Granada disc brakes and spindles. Also added dual bowl master cylinder and per-portioning valve.

These improvements were great and I had no vibration issues with the car until a couple of weeks ago. I was getting onto the freeway and shifted from 3rd to 4th around 4K RPM. When I got into 4th the entire car started vibrating violently like never before. I immediately got off the freeway and checked the drive shaft and U-Joints. Nothing seemed out of the ordinary and It was late at night so viability was poor. I started her back up and proceeded to drive around slowly. The strong vibration was still there. Think of a sub woofer cranked at 40-60 HZ and you will begin to understand the type of vibration I was experiencing. Parked it and towed it home.

I took the car over to a 60's era ford mechanic in the city. We got the car up on some jack stands and had me shift through the gears. The vibration was present in all gears. He dropped the tranny and discovered in the process that the drive shaft had zero front to back play. Also, the transmission extension housing bushing and rear crankshaft bushing were out of round. He replaced them and the rear tranny seal. I decided to replace the clutch with a Zoom branded one and resurface the flywheel while he was in there. I also replaced drive shaft, U Joints and slip yoke which all showed signs of wear.

The motor mounts were cracked and also got replaced. When he was removing the bell housing my mechanic saw that the bottom two bolts were stripped. He tapped with 3/4" threads and replaced the bolts. As we were testing the car through out all of these changes I told him that the shifter lever was pulling to the left when releasing the clutch pedal. Also my accelerator pedal was pulsing like mad. It made low RPM acceleration extremely difficult because the pedal would be jumping up and down causing the car to lunge on every pulse as it hit the bottom of my foot. The new bell housing bolts and motor mounts seemed to have cured that issue.

We took the car for a spin and the vibration was greatly reduced but still there. It is particularly noticeable at freeway speeds while in 3rd and 4th gears above 2K RPMs. I also want to note that the car never seems out of control. The steering seems fine and I don't notice any sort of hop or wobble. I had an alignment done when I did the front brake conversion.

I'm getting some clutch scrubbing as well. It seems to come and go. When it does happen I notice it in neutral at a stop and feel it through clutch and brake pedals. The release bearing was replaced when the clutch was installed. It appears to need an adjustment but thought it was worth noting.

I then took the car to my tire guy and had the wheels rebalanced. I figured it was time to make sure they weren't adding to the madness. They were off by an once or so on 2 out of the four wheels. Crazy thing is I feel like the vibration may be worse after the wheels were balanced. I may be psyching myself out though and its exactly the same as before the balancing.

So I drove the car one day (same day I got the wheels balanced) after getting it back from my mechanic until we decide the next move. I was going over the car when I noticed a fairly large puddle of transmission fluid under the car. The new rear tranny seal sheared off and was freely rotating on the slip yoke causing the tranny to leak.

One of the reasons that I was looking under the car was because the old bird had been leaking motor oil from the rear crank shaft seal before all of the vibration issues I've been having to top of the motor oil frequently. Now that leak seams to be gone and the puddle of fluid was from the tranny. My power steering control valve leaks but that's another topic all together.

I'm new to the classic car hobby and enjoy the great information you all make available. Any assistance would be greatly appreciated. I looked at countless posts on here and have found similar issues but not close enough to get me pointed in the right direction.

I'd like to give a shout out to Bill of the Falcon Club in Virginia. I contacted him when I was buying the car from a seller in Virginia. He was extremely helpful and responsive to me when I contacted him out of the blue through the falcon club website. Thanks again Bill!

Adam

 

4/05/2013 6:04 AM  #2


Re: 1964 Falcon Sprint HT Vibration Issue

There are many possibilities but I would look carefully at the driveshaft - u-joints and balance.  You may have had a balance weight extract itself.  In some cases what you can "feel" in a u-joint by moving it by hand is not what it does under load.  I have a co-worker that lost a u-joint at greater than highway speeds and the carnage included breaking the tailhousing off the transmission and ripping the front out of the bellhousing - so this is not something I would wait and see on.  Replace them both and have it balanced.  If its cured you are in good shape if not, you have eliminated one possiblility.

 

4/05/2013 8:30 AM  #3


Re: 1964 Falcon Sprint HT Vibration Issue

Had an experience like that when I was in college in 1970. Fraternity brothers 67 Mustang had very bad vibration at speed and worse with load. Tranny started leaking and all. Ended up being the layshaft in the tranny. He even had the clutch act up since the layshaft bearing had long departed and the input shaft bearings had followed suit. We ended up trashing the gearbox and found a usable one at a local scrap yard. Nowdays I have a battery owered wireless little camera that I have mounted under several cars to help trouble shoot lots of stuff, it would be my first thing to do in your case. I set it up to record on my laptop and go for a ride. Then look at what is going on under the car when it vibrates. Anyway, I would look closely at the gearbox.

 

4/05/2013 8:35 AM  #4


Re: 1964 Falcon Sprint HT Vibration Issue

Also, since you ran with no slide in the tranny yoke, you may have trashed the input shaft to main shaft bearing in the tranny which could do the same things you are seeing.

 

4/05/2013 8:46 AM  #5


Re: 1964 Falcon Sprint HT Vibration Issue

Did you shorten D/S as you said no end play? As GPatrick mentioned, make sure Ujoints  move freely....
Howard

Last edited by hmartin025 (4/05/2013 8:47 AM)

 

4/05/2013 12:03 PM  #6


Re: 1964 Falcon Sprint HT Vibration Issue

Adam's a buddy of mine so I can report that the driveshaft has been replaced with a new correct length unit (presumably properly balanced), u-joints are new, slip yoke is new, clutch is new with new pilot bushing and the tailshaft bushing has been replaced as he noted. Here's a pic he sent of the new output shaft seal that came apart within a couple days of being replaced. Might be a little hard to see but the seal flange and some of the seal separated and are riding at the front of the yoke.

http://i49.tinypic.com/dww7qt.jpg


I think DC may be on the right track (unfortunately) and the tranny might need some internal attention, makes sense that a drive shaft with no freeplay would hammer pretty hard on the tranny bearings. The guy working on the car said that both the pilot bushing and the tailshaft bushing were out of round and a couple of the bellhousing bolts (I think the bottom two tranny to bellhousing) were stripped out.

Another thought, with bad motor mounts and the two lower bolts not really holding the tranny to the bellhousing tightly seems like you'd have kind a pivotpoint at the top two tranny bolts constantly messing with tranny to crankshaft centerline relationship which could partly explain some of the damage seen so far. Just thinking out loud here, don't really have a lot of experience with this kind of problem.

Last edited by McStang (4/05/2013 12:12 PM)


(Pinto!)
 

4/05/2013 3:47 PM  #7


Re: 1964 Falcon Sprint HT Vibration Issue

If not the tranny...  I did not see anything noting if this happens with the engine in neutral at idle.  A busted or slipped harmonic balancer can make the type of vibration you described,  but it would also do it sitting still with the clutch pushed in.

If that is not it, then I would vote transmission.  But balancer is easier to fix!


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

4/05/2013 4:12 PM  #8


Re: 1964 Falcon Sprint HT Vibration Issue

Thanks for the ideas guys. My mechanic is stopping by my place tomorrow to put a new seal on. I'd like to remove the transmission extension and check for free play.

I'll also check the motor mounts, fan and harmonic balancer. Not sure about the tranny mount.

The drive shaft, U Joints and slip yoke are all new as of last week.

I'll keep you guys posted.

Thanks

Adam

     Thread Starter
 

4/05/2013 4:14 PM  #9


Re: 1964 Falcon Sprint HT Vibration Issue

Steve,
I now only feel the vibration at freeway speeds.  In neutral I get intermitent clutch scrubbing but I think that just needs an adjustment.

Adam

     Thread Starter
 

4/05/2013 4:31 PM  #10


Re: 1964 Falcon Sprint HT Vibration Issue

The guy working on the car said that both the pilot bushing and the tailshaft bushing were out of round and a couple of the bellhousing bolts (I think the bottom two tranny to bellhousing) were stripped out.

, with bad motor mounts and the two lower bolts not really holding the tranny to the bellhousing tightly seems like you'd have kind a pivotpoint at the top two tranny bolts constantly messing with tranny to crankshaft centerline relationship

 That alone would be enough to "tear up" a tranny,in my book.
Bet that's causing the problem!!
6sally6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

4/05/2013 6:35 PM  #11


Re: 1964 Falcon Sprint HT Vibration Issue

I'm with you 6sally6, thinkin' about it and chewing it around with the1stman it would make sense that the too-long driveshaft is probably the reason the two lower tranny to bellhousing bolts were stripped out. The DS would have been banging the tailshaft over and over and trying to lift the tranny up at that end, working over the input shaft bearing and everything in the tranny at the same time. Bad motor mounts would just pitch in to help with the mayhem.


(Pinto!)
 

4/05/2013 6:50 PM  #12


Re: 1964 Falcon Sprint HT Vibration Issue

Not 100% sure yet but I'm thinking its the transmission. If I do end up replacing the T-10 I'm interested in putting in a T-5.  What should I look out for when sourcing a replacement and what sort of modifications if any would be needed for the swap?

With all of the posts I've received and doing some other research I feel like the drive shaft being too long caused a chain reaction. Since the drive shaft was pushing into the tail of the transmission it wore out the bushing and has proceeded to beat the hell out of the gearbox.  Also, since the drive shaft was pushing into the transmission extension it caused the bottom two bolts on the bell housing to strip out. Seams to make sense.

McStang and I have been wrapping about it for a minute and I think its time for a replacement.

Let me know what you guys recommend for a replacement.

     Thread Starter
 

4/05/2013 7:16 PM  #13


Re: 1964 Falcon Sprint HT Vibration Issue

I cannot see how the bellhousing bolts would have gotten stripped put.  The bell would have cracked long before that occurred.  Totally unrelated...  Plus, the rear driveshaft mount would have had to be ripped completely loose for anything like that to occur.

Your choice to change to a T5 is better idea.  Might have to mod the hole where the shifter comes up on a Falcon.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

4/05/2013 9:21 PM  #14


Re: 1964 Falcon Sprint HT Vibration Issue

Any recommendations on t-5 models, bell housings and first gear ratios for a 289 with 3.25 rear? A reasonable first and second gear are needed. Reality of living in the hills of San Francisco. Also my 289 seems to have a mild cam but not putting out more the 300 hp. Thinking about putting hi-po exhaust manifolds for my dual exhaust setup and cable clutch while I'm at it. 

     Thread Starter
 

4/07/2013 5:07 PM  #15


Re: 1964 Falcon Sprint HT Vibration Issue

So we replaced the seal at the tail end of the tranny yesterday.  Doesn't appear to be leaking anymore. I'll keep an eye on it.

Also I adjusted the clutch linkage and it seems to have taken away the scubbing feeling through the pedals.

I tried going down hill and put her in neutral.  Same vibration.

One thing I did notice today is the car will behave differently if I'm cruising down hill or going up hill at the same speed. The car appears to vibrate significantly less if I'm accelerating up hill.  Cruising down hill or on the flats with little or no pressure on the accelerator at 45 MPH or more causes the vibration to start up.  Also, if I'm in 3rd accelerating up to 45 -55MPH or more the vibration is less than if I was cruising in 4th at 45 MPH or faster.

It always starts to shake around 2K RPM in 4th above 40 MPH if I'm not going up hill. If I'm going up hill the vibration is still there but less until I get around 3K RPM.  

Debating getting the old T-10 rebuilt or doing a T-5 conversion with the current bell housing and using an adapter plate.

I also tried a brand new set of 15" wheels (Torque Thrusts same as mine) and same sized tires that have never been on the road.  The symptoms where exactly the same.

I check the harmonic balancer and seems to be solid.

I'd like to know the best way to check for bent spindles and axles.  How do you go about checking them?

     Thread Starter
 

4/07/2013 6:24 PM  #16


Re: 1964 Falcon Sprint HT Vibration Issue

Along with your driveshaft and u-joints that can change under load versus coast, up-hill, etc., it also sounds like it could be a shift in driveline angle.  I can't see how that would happen suddenly unless you dropped a shim or broke a perch/mount on the rear.  Can you measure your driveline angle and pinion angle to make sure you are about 3 degrees on the engine/transmission and perhaps 2 degrees up on the pinion?  If the pinion is rotating up excessively it could cause the vibration you describe if it does it under load and not while coasting.  I love to spend other people's money but I would change the u-joints just to make sure you are not fighting a problem that you can't feel when twisting them by hand.

 

4/07/2013 10:32 PM  #17


Re: 1964 Falcon Sprint HT Vibration Issue

I had this happen once with a pick up . It ended up being the pinion bearing in the rear end.

 

4/16/2013 1:01 AM  #18


Re: 1964 Falcon Sprint HT Vibration Issue

So I had some help and pulled the transmission out over the weekend.  My new slip yoke is showing extensive wear for being less than two weeks old. Also the output shaft isn't balanced.  Its easy to see the output shaft is bent if you manual spin the input shaft.

Looks like I found the cause of the vibration.  Long driveshaft really did a number on the old bird. All that banging against the extension ruined a perfectly good T-10.  Luckily the rest of the tranny seems to be in really good shape. 

I'm on the hunt for another T-10 output shaft and slip yoke.  Let me know if you guys know of any sources for the output shaft.  Yoke seems to be readily available.

Thanks

     Thread Starter
 

4/16/2013 5:31 PM  #19


Re: 1964 Falcon Sprint HT Vibration Issue

I usta have a 64 Sprint,yeeeears ago. Sweeet little ride. I'd swing for the T-5 instead of a rebuild on the T-10.Pick up some MPG and the T-10 isn't that strong of a tranny to begin with(I think!)  Check the junk years. With a 3.25 gear a T-5 1st gear will REALLY pull good. I would be very happy with that set-up!
6sally6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

4/16/2013 8:27 PM  #20


Re: 1964 Falcon Sprint HT Vibration Issue

the1stman wrote:

.....My new slip yoke is showing extensive wear for being less than two weeks old. Also the output shaft isn't balanced.  Its easy to see the output shaft is bent if you manual spin the input shaft.

Had this happen with my T5 in less than a month of driving as well. Had an extra 3/4" taken out of the Aerostar aluminum driveshaft and rebalanced at the company's cost that did it the first time. http://i45.tinypic.com/29moe38.jpg

 

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