np203 vibrating after 55mph!

[MrMarty51]

Are the ujoints "centered",in other words when You have the drive shaft removed do the ujoints pivot freely without any binding?
When installing ujoints they have to be centered,after installing into the shaft and yoke the joints have to be "pounded" so that the caps are firmly against the retainer snap rings or clips,other wise the joints will bind and cause vibrations as what You describe.

 

[Kapdin]

yea the are deff free, they are out to the snaprings but thats were my slop is, the u joint has a tish of play when pushed cap to cap.

 

[MrMarty51]

yea the are deff free, they are out to the snaprings but thats were my slop is, the u joint has a tish of play when pushed cap to cap.

That tish of play could be the cause.
I think I would try an auto salvage for a different shaft that has good u joints in it and see how that affects the vibes.

 

[crazy4offroad]

With the u-joint and clips in place this is what I would try, it's pretty much the same thing a driveline shop does. Place the yoke in question on a solid piece of wood, like a 4x4 or 6x6. Kind of angle it up so the ear is contacting the wood. Then with a brass mallet lightly smack the opposite ear and after each smack check it to see if you've taken the slack out of it. U-joints can be a little tight when brand new, just not binding or feel like they have a "drag" spot along it's path of travel. If you don't have a brass hammer but have someone to help by holding the driveshaft at the correct angle, you can place a 2x4 on the top ear and use a regular steel 2# hammer. Just be careful to not pop a clip, because then it will be too tight to seat.

 

[MrMarty51]

There are times when installing a new U joint that the "Ears" that the caps slide into are not spread far enough apart to get the clips seated,rather inside or outside,and I use a punch and a hammer to pound the "Ears" out far enough to get the clips to snap into their grooves.
Then,the U Joints still have to be centered and if there is any binding then either the caps did`nt pound out to the end or else the "Ears" need a bit more nudging outwards to get the yoke to shaft joint to rotate freely,without any binding.

 

[Kapdin]

well, i got bigger problems at the moment... my front left tire blew apart. looks like the blets let loose, wonder if thats part my problem also.

 

[MrMarty51]

Might be,just might be.thats alllll

 

[Kapdin]

SCORE! lol stole this freebie, wish had 2.

You must be registered for see images attach

 

[77 K20]

I've had exactly the same viberation you have described on my '77. It was there when I first bought it. Now that it is 7 years or so later I have changed (for other reasons other than chasing the viberation)

-transfer case with another part time 203
- rebuilt the rear drive shaft with new U-joints
- new tires/wheels
- had those tires rebalanced
- added new shocks
- new body mounts.

Still is there. Being that I don't drive it on the highway very much, I just don't care what it is anymore.

 

[Kapdin]

Well gents, took the truck yesturday to work and that tire was the biggest part of my problem, so im assuming the other front (which has the same age and millage) could be the last bit of my vibration. But really i don't "Feel" the vibration now but i hear it in the 4x4 shifter. Still maybe swap my yolk 180?

 

[Wildjoe330]

Do all of these trucks with the 50 65 mph pulsating vibration problem have the NP 203 Transfer Case??? All Dodge, Ford, Chevrolet, have these put into them. And I have seen a dodge online with the same issue. Does the NP203 have need for a new bearing on the front of the output Shaft???

I was just told by a long time sales person that they used to knock off or even grind off the drum balance weights so new rims would go on.

77 K20, 50 to 65 pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22

 

[Wildjoe330]

Even 1/32 can cause vibration. Inspect the yokes and make sure the "ears" that retain the u-joint caps aren't excessively worn. This is a good place to order parts if you don't have a good driveline shop nearby
http://www.dennysdriveshaft.com/c258_cv_parts_yokes_u_joints_hardware.html

Have you replaced a 203 output yoke that has taken out the 50 to 65 mph vibration?

I am thinking about changing this front output bearing for mine to see what it will do.
look at the video at 3.55 this is showing a 205 rather than a 203.

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77 K20, 50 to 65 pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22