There's no way I know of to change that bushing in the car, other than to pull the tailshaft housing off. 

OReilly catalog shows the T5 and TKO use the same bushing. I replaced mine on my TKO600 in the car using the proper tool. Pretty easy. It made no difference, though.

In my recent studies on T5 transmission rebuilding, I found info that stated the T5 bushing is not replaceable because it is a factory honed fit that cannot be duplicated after use. I don't know if that is true, but that is what a transmission expert said.  Maybe Glen's 65 5.0, one of the resident T5 experts, knows more about that.

From my experience on chasing the five speed vibration issues, unless you have really excessive looseness at the driveshaft, like 1/16" of play, I would look elsewhere for the problem.   Some looseness is normal.

thanks guys,i talked with glenn yesterday,he thinks I should start with the pinion angle first as the tailshaft bushing and driveshaft only have 1k on them.i will start there this week.the only old part on the driveshaft is the old slip yoke 

One other to check is to clock the bell housing. There's a write up in the mustang manual (red for mine) under the chapter for clutches. Very important when using new components.

You don't have to pull the trans.  You can drop the crossmember, pull the speedo cable, and take the tailshaft housing off with the trans in the vehicle. 

a quick update.i've installed 4 degree wedges to get the correct pinion angle.i got a new tailshaft bushing and seal.I've installed the seal(holding off on the bushing for now).bought a new slip yoke and ujoints.took the driveshaft back to the company that made it last year to have it balanced they called and said it was bent and needed to be replaced.they went good for all but $50.i will install tonight and road test.when I installed the t5 last year I was trying it out and on a hard launch I got a lot of wheel hop for which the next weekend I installed traction masters,could this wheel hop have caused the driveshaft to warp?

Last edited by gordon43 (9/22/2016 11:43 AM)

Michael H. wrote:

TKOPerformance wrote:

You don't have to pull the trans.  You can drop the crossmember, pull the speedo cable, and take the tailshaft housing off with the trans in the vehicle. 

Yes, BUT.... On a T5 there's a roll pin in the shifter opening that has to be driven out before the tailshaft will come off.  It's pretty tough to get to with the transmission still in the vehicle.  On a fox body mustang it's doable because the shifter opening in the floor board is bigger so you can access it from inside the car with the trasmission still in the car.
 

That is true, you will have to pull the shifter and drive the roll pin down through the shift cup.  If you remove the shift handle and drop the crossmember and trans down you should be able to unbolt the shifter from under the car, and you should have enough clearance to pick the shifter up and move it rearward to get it off the trans.  You can then drive the roll pin down from inside the car.  In the end its probably easier to just pull the trans.  A T5 isn't that heavy, and this task is all a lot easier on the bench.

FYI, I couldn't get the shifter off the trans in my Fox body just by pulling the boots from inside.  The front two bolts were tucked up under the sheetmetal and are too long to get out without dropping the crossmember.  The floor opening in the Fox cars for some crazy reason was cut by hand and they are all over the place.  Sometimes they're square, sometimes they're a trapezoid, they vary as to where they're cut by several inches car to car.  On other cars I've been able to swap the shifter from inside the car just by pulling the boots and unbolting the shifter.  I guess my car was a Monday car and the line guys were a bit hungover when they built it.  That would explain one of the rear quarter panel braces not being welded in right too I suppose. 

In our 66 HT, 5.0, AOD, 8" open w/3.55 gears...I chased a 70 mph vib for 15k miles.  It wasn't terrible but it was there and really annoying.  I had the DS balanced twice, wheels balanced three times at two different shops, checked wheels for run-out with a dial indicator, checked tires for OOR, checked for bent axles, hell, I even made a tool to balance the brake drums, checked the tail shaft bushing, and checked the DS ends for true center, double checked pinion angle.  Nothing showed up or helped.  Then one day a friend and I got a wild hair and since I had a open rear axle, I jacked up the left side, and with the car facing OUT of the garage, ran it up to an indicated 70 mph....no vib, no bounce.  Then I did the same thing with the right side raised and the vib was there and my friend said he could see visible bounce. 
At that point I decided it had to be a bent axle housing and started making plans for the 8.8.   No more vib at any speed that I have the guts to take it.  FIXED!! Smooth as a baby's bo-hiney.

Just saying,  You may want to check that housing for straight. 

BB

Last edited by Bullet Bob (9/22/2016 8:04 PM)

I had to remove it for clerance. Also had to cut off the mounting tabs. If you can leave it. I would. I did go back and put the the one back on the t5.

What I read seemed to indicate that the origination of the issue was the gears themselves due to the fact that all gears have minor surface imperfections and "hum" at a certain frequency.  Now, whether that frequency translates into a harmonic certainly has to do with what's around it and different materials and suspension styles would have different resonant frequencies. 

Some people speculate that the frequency of the hum has something to do with the ratio of the gears and that with the stock 2.73s found in most 5.0s it was an issue, but when swapping to say 3.73s the frequency changed enough to no longer need the cancelation of the dogbone. 

It is interesting that Ford doesn't seem to have used the dogbone on leaf sprung vehicles.  BUT, I wonder if this also has to do with the fact that leaf sprung vehicles are trucks and never have 2.73 gears. 

Just for info.

My 66 has had the same vibration at speeds above 72 mph with 3.0, 3.89, 3.50 and 3.70 gears in the 9" and with a T5 and a TKO600 five speed. 

I am beginning to think that only a vibration or frequency canceling device like the ones on the Fox transmission and rear end will ever cure my car's problem.

There must be SOMETHING to do with the five speed increasing the speed of the output shaft so it spins faster than the input shaft.  Gary Patrick is pretty much my only hope in resolving the problem.

Unfortunately, I do not have the advantage of all the smart engineers and their testing equipment at Ford.

TKOPerformance wrote:

Michael H. wrote:

TKOPerformance wrote:

It is interesting that Ford doesn't seem to have used the dogbone on leaf sprung vehicles.  BUT, I wonder if this also has to do with the fact that leaf sprung vehicles are trucks and never have 2.73 gears. 

I know of at least one truck that came with 2.73 gears.  My '91 F150 Daily Driver has an 8.8 rear with no dogbone and it came from the factory with 2.73 gears... changed to 3.27 gears now.

Wow, that's really low for a truck.  Usually trucks got at least 3.08s.  Most I've seen were in the 3.55-3.73 range, and the 1st gen Lightnings had 4.10s.  I guess "never" is a dangerous word...

Lol... yeah.  Never is a dangerous word... but I've gotta think it was pretty rare for a truck to get gears that tall.
When I swapped to the 3.27 gears I got better all around acceleration and kept the same city mpg.  Oddly enough I actually picked up about 2mpg on the highway!... I guess because the truck was cruising much closer to it's peak torque RPM instead of lugging.