Ujoints

[Cant Write]

Let’s talk about vibes, the one I’m trying to cure is a high frequency vibe felt above 70 (although I felt it much less pronounced around 57mph then went away).

It’s felt in the low back/seat above 70.
It’s more intense on acceleration but still felt on coasting

Thing to try: flip the rear yoke to the diff 180.
Swap front to rear tires (I don’t think it’s tires)
Replace front joint
Is the damper on the front yoke replaceable? Rubber is dry, and starting to chip away.
Finally take it into a driveline shop and check run-out?

Thoughts?

 

[Cant Write]

I had such bad luck with those lubed for life spicers when they first came out that they were giving me a couple to take on a trip before I would leave. Hopefully they're better. Spicer used to be the Cadillac of u-joints. I'm having much better luck with SKF brand from Napa.
Oh and I always use greaseable.
They built the driveline with the sealed ones in it when I had it done that's the only reason they were in there I use hydrox paint grease to grease my u-joints and wheel bearings front wheel bearings are 14 years old 130,000 mi and the Grease still looks new

I use SKF for my sealed unit bearings on my GM products. I’m a fan, thanks! ...as the guy behind the NAPA counter never mentioned SKF and I prolly would not have hunted Spicer down.

Now about that grease, when I Google-machined “hydrox paint grease” a whole lot of not-what-I-wanted came up. Do you have more info please!

Also, what grease do you use for ball joints ..... er ...... steering/suspension?

 

[Cant Write]

I tried to cure high speed vibrations for years. It might not be the U-joints - I replaced the U-joints, steel wheels, tires, and Centramatic dynamic wheel balancers (beads contained in a circular tube that mounts between the wheel and the hub) - all with little improvement. Finally heavy 10 ply Michelin tires did the trick. The rotating mass of those heavy tires. I've noticed that when removing and replacing a wheel can upset the balance and set up vibration - clocking the wheel on the hub (removing and replacing the wheel in a different position on the same corner) can either induce or reduce vibration.
U-joint wear can be judged by taking the weight off the rear wheels, transmission in neutral, and checking for play. The front U-joint usually has a little more play because of the output seal.

I sure would appreciate it when you have the time to read through and help me where I’ve failed!!

 

[Black dawg]

I would try flipping it 180, but most likely this is a balance issue.

 

[Rdnck84_03]

Is the damper on the front yoke replaceable? Rubber is dry, and starting to chip away.

I believe you would probably have to replace the yoke and damper as a unit. It looks to be assembled same as an engine harmonic damper.

James

 

[Cant Write]

@Black dawg @Rdnck84_03

Thanks for hanging with me fellas. I will swap it 180 and see if I get a change.

I also read that some driveline shops will remove that damper on the yoke and rebalance the whole shaft for a reasonable price.

I could also swap wheels, or slowly clock them, or take them to a shop to check run-out/wobble on them, but it sure doesn’t feel like tires to me. But I’ve been wrong many times before.

And the tires are 10-ply, 8k miles, I will get make and look at weights.

On shift through Thursday.

 

[Black dawg]

As far as the life series spicers and problems, there was a time frame when the amount of grease that was in them was inconsistent, then guys would add grease (possibly non compatible grease) and usually too much. If you add grease to them and they already have enough, I am not sure what takes place, but they will not last. When you pull them apart the grease would be black and burnt up. I had a few fail to this, even after using spicers grease, until I learned they only need some grease lightly coating the rollers and a dab in the end of the cross. But most of the time they do have the correct amount of grease in them.

As far as SKF joints....I only use those when I have no choice. I refuse to use a part that is dimensionally inconsistent. And they only last if you love greasing stuff.



Does this vibration feel like a shake, or a buzz?

 

[typ4]

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This grease for everything.

 

[Cant Write]

Does this vibration feel like a shake, or a buzz?

Definitely more of a high frequency buzz.

 

[Rdnck84_03]

Could it possibly be engine harmonics? Like maybe a couple injectors popping a little early.

James

 

[Cant Write]

Maybe, the “buzz” which would be a lower frequency buzz but not low enough to qualify as a shake comes through the seat and low back of the chair.

It does not buzz in 3rd (direct) or 1st/2nd if I am accelerating hard from a stop or dropping to 3rd to prepare for a grade pull.

At 75, I actually thought, man the engine is quiet and smooth.

I should take the doghouse off and video the shaft at 75 if I can see it.

 

[Black dawg]

Really just sounds like shaft balance to me. Really hard to deal with that stuff around here, with d shaft shops being hit and miss for balancing.

On my own stuff I have reverted to the hose clamp trick.

 

[Rdnck84_03]

Only reason I threw that out is because I have an injector that maybe once every 3 or 4 months will act up and it feels like a driveline vibration. I know mine is an injector because I can hear the sound change when it does it, just never do it long enough to be able to crack lines to isolate it

James

 

[Rdnck84_03]

I agree with black dawg on the shaft balance though, especially since the rubber in that damper really doesn't look healthy.

James

 

[Cant Write]

On my own stuff I have reverted to the hose clamp trick.

Tell me more, do you put the clamp more in the middle or towards one end?

Then I will happily turn it a 1/4 at a time until I find the least vibes. Then take it in to a driveline shop. (2-hrs drive)