Still vibrating but better
 

I put the new S-10 5 spd with a new open driveshaft and had a vibe from 32 to 49 mph. then it would go away above that. Checked alignment, rebalanced shaft and all new universals again. Now it only vibrates from 51 to 58. If not moving and rev the engine in neutral there are no vibes. Clutch in or out. Driving at 58mph and hold in the clutch, it will vibrate all the way down to 20 mph. in neutral or in 5 th gear. I have balanced the fly wheel, checked bearings and universals. WHAT AM I MISSING. The truck is my 37 ford pickup with a 53 8BA and a 84 S-10 trans
and open drive shaft.

Re: Still vibrating but better
 

Have you checked your operating angles? There's lots of youtube videos on the subject and playing with a inclinometer (angle finder) is kinda' fun.
Just do a search on "Driveshaft operating angles".

Re: Still vibrating but better
 

The driveshaft needs to have some angle (not totally straight line) between the output shaft on the transmission and the input shaft on the pinion. And the angles for both need to match as close as possible. Also the u-joints have to be in phase with each other.

Re: Still vibrating but better
 

I was going to say have you checked the transmission to engine alignment. I'm not sure if that would be relevant though.

As above, motor/trans and pinion should be close to parallel but not directly in line and UJs should be in phase. Wheel and tyre balance is also important.

Mart.

Re: Still vibrating but better
 

I agree on that. The tires & wheels are worth checking too. Any rotating component can cause vibration. A bent wheel or axle shaft can also vibrate.

Re: Still vibrating but better
 

Not trying to hijack but......is having the u-joints in phase only taken into account when a drive shaft has been altered....change in length or in-put yoke.....if you just change u-joints do you have to consider “phasing”.....again, not trying to hijack but this thread has brought up some questions.....Thanks....Mark

Re: Still vibrating but better
 

U-joints always have to be in phases. That is normally built into OEM driveshafts.

Re: Still vibrating but better
 

What rear end are you using?
Find the Tremec app "TREMEC TOOL BOX". Load it on your i-phone and use the driveline angle finder.

Need to know about the rear end.

Re: Still vibrating but better
 

Ok...thanks. I did some work on my ‘50 Fordor (u-joints/tuneup) and have developed a vibration. I’ve checked everything I touched and haven’t found the issue.
I’m putting a T-5 in my ‘51 Tudor and will be paying close attention to u-joint phasing.
Thanks....Mark

Re: Still vibrating but better
 

Is it a vibration only in overdrive? How much u-joint yoke is hanging out of the trans ?
When od automatics first became common place , it was very important to have a good bushing in the trans tail shaft . Any slop or excessive driveshaft yoke protrusion would create a vibration , usually worse in od . If you can accelerate past the current vibrating speed in a lower gear then shift into od and it starts vibrating , it'll continue to vibrate till almost stopped .
Good luck

Re: Still vibrating but better
 

Google the Spicer drive line operating angle calculator. you will need the output yoke angle ,the driveline tube angle and the pinion yoke angle, I sometimes use the crankshaft snout as a reference angle point in lieu of the transmission output yoke and a good flat surface on the differential yoke to find pinion angle.

Re: Still vibrating but better
 

Take the tires off and run it on good, jack stands and see if it's still vibrating.

If it still vibrates, check out the trans and rear end, with a stethoscope.

Re: Still vibrating but better
 

If the driveline was shortened or lengthened, the U-joints could be slightly out of phase but balance OK. As mentioned above, check all 4 wheels and tires for being bent or out of balance.

Re: Still vibrating but better
 

Fordestes nailed it ! Many guys believe there are 2 angles that have to be right , but there are really 3 . The vibration started after he went to a different transmission .
With all due respect, that will not affect tire balance . The vibration is in the driveline .

Re: Still vibrating but better
 

Check to see if the driveline shop got the u-joint cap eyes in a perfect alignment or (shaft could be damaged or twisted) on the tube, if not aligned this is an out of phase condition ,being out of phase will cause what is known as a secondary order vibration, if there are multiple drive shafts or a slip yoke they must be phased or timed centers with the u-joint caps aligned horizontally to avoid each shaft or yoke binding against one another. if all is in order rather than try to explain how to calculate the working angle, use of the Spicer calculator will be easier, If you don't have an inclinometer ( another word for a fancy type protractor), get a cheap school supply protractor with a center hole on the flat surface and tie an 8" string through the hole and tie a small weight on the other end ( I use a 5/16 nut ) place the flat side of the protractor against the drive line tube bottom side and read the degrees where the string lays across the numbers, record the reading, then use the same method to measure the pinion yoke, in the event the protractor wont clear the yoke ,grab a deep socket and place it vertically flat against the u-joint trunnion/ bearing cap surface as to extend the bearing cap surface , sometimes the bearing retainer clip will need to be removed in order to have a flat surface ,then read the protractor and record , do the same with the front transmission u-joint, this will give you the numbers to plug into the calculator .

Re: Still vibrating but better
 

Check that the rear spline adapter is tight ,some have the spline not machined as a tight press fit .I have heard A lock tight product can be used as a fix ,

Re: Still vibrating but better
 

Had the same type of problem when I put a T-5 trans on my 50 8-BA. Trans was set at 2 degrees down and rear was set at degrees up. Still had same problem. Finally compared the input shaft yoke into the trans with an input shaft yoke for a T-5 and there was a considerable difference in length and how far it went into the trans. Swapped out the trans yokes and problem solved. You might also check the tail shaft bushing for slop.

Re: Still vibrating but better
 

Just an insurance point, we're checking these set up angles, with the weight on the suspension.

Re: Still vibrating but better
 

Original rearend

Re: Still vibrating but better
 

So how is it mounted?