Jackstands + no wheels = heavy vibration?

[bob8619]

Originally Posted by jeffahart

I see something new, I see something new! Did it vibrate before that new yoke? Did you turn the shaft? See if that changes anything. I always put my shaft back in the way it came out.


j

Yeah the yoke was replaced in attempt to fix this vibration issue. I was able to wiggle one of the u joint caps inside the yoke while it was fully installed so figured it needs to be replaced anyway so just swapped it.

I haven't rotated the shaft 180 since installing it yet no. But as I mentioned in my last post, the raising of the rear end seems to be fixing it or at least masking it.

[Popcorn W]

Have you changed the driveshaft recently? It doesn't look like that yoke is far enough up in the trans to me.

[jeffahart]

OK, ya. It's a tough one. I like the idea of the wood blocks for a test to see if there is change. What's your angles before and after. Turn the shaft to shut me up! It's possible the yoke fixed the problem and caused another one. I've seen more annoying stuff. Do the shaft twice. Once 180. And once only turning the rear yoke 180. See what happens. Will only take less than a half hour maybe fifteen minutes. It's free! That's what I would do next. I am cheap and lazy. I do the easy stuff and free stuff first. Plus these exercises get you to thinking. Then keep on going.


j

[bob8619]

Originally Posted by Popcorn W

Have you changed the driveshaft recently? It doesn't look like that yoke is far enough up in the trans to me.

No I haven't but there's no telling what the previous owner did to it.

[bob8619]

My guess would be that stiffer springs (like my wood blocks) would amplify an imbalance as there would be less absorption by the springs so I'm inclined to think that the changing of my angles are what's causing me to not feel any vibrations anymore. I could be wrong though.

[jeffahart]

Originally Posted by bob8619

My guess would be that stiffer springs (like my wood blocks) would amplify an imbalance as there would be less absorption by the springs so I'm inclined to think that the changing of my angles are what's causing me to not feel any vibrations anymore. I could be wrong though.

Get the new springs you want to run. Then correct pinion angle. Or have a shop do it. Setup needs to be correct first. Else, other stuff gets destroyed!



j

[bob8619]

I've been thinking about it and putting the wood in my springs would only be increasing the driveshaft angle right? Can too little angle even cause vibrations? Oh and is it possible to install a one piece drive shaft backwards?

[bob8619]

Also this is my transmission mount which looks worn but not sure if that can lend to the underlying problem or not.

[hjewell2]

I spy my little eye,,,input shaft not in far enough on trans

[bob8619]

Originally Posted by hjewell2

I spy my little eye,,,input shaft not in far enough on trans

You have a long bed with th350 and one piece drive shaft and the yoke goes in further?

[bob8619]

There is 2-3/8" that goes inside into the housing. Thats not sufficient? Thats a whole new can of worms if not.

EDIT: And thats not taking into consideration that the tail shaft actually sticks out 1/2'' beyond the hosing so thats just short of 3'' of spline contact vs the 1.25'' of exposed yoke on the outside.

[bob8619]

I went and bought an angle finder and the different between the two angles is 2 degrees. Isn't it ok to be within 3?

[Popcorn W]

Originally Posted by hjewell2

I spy my little eye,,,input shaft not in far enough on trans

Yea, that's what I told him earlier.

[Popcorn W]

Originally Posted by bob8619

There is 2-3/8" that goes inside into the housing. Thats not sufficient?

Should only be roughly 1/2" showing. You may have 2-3/8" inside, but too much outside makes it unbalanced.

[bob8619]

Originally Posted by Popcorn W

Should only be roughly 1/2" showing. You may have 2-3/8" inside, but too much outside makes it unbalanced.

How could that be? That section of yoke spins regardless, if it's unbalanced outside then it would be unbalanced inside too.

[bob8619]

Error post. removed.

[bob8619]

Removed

[Mike_The_Grad]

I'm having similar vibrations in my 72 lwb c10 with 2 piece driveshaft. New carrier bearing, all three u joints new. Haven't thought to check out the slip joint between the front and rear driveshaft, or the pinion nut.
Were you able to get the vibration figured out?

[AussieinNC]

Couple of observations...

The yoke, as mentioned by a couple of others, appears to be way too far out of the trans...I have always been told by driveshaft guys when ordering a new shaft...

"Push the yoke all the way into the trans then pull it out 3/4"...this yoke appears to be out at least two and half inches...

If the truck has been run with the yoke out this far, it is possible the bush in the extension housing has been chopped up...

Can you move the yoke up and down inside the end of the trans extension housing?

The trans can be damaged if that rear bush is damaged...I have personally witnessed the rear bush actually walk out of the housing and end up sitting on the output shaft...

That trans mount is TOAST ! and it looks like the metal part of the mount is touching the cross member...