Driveshaft vibration video

[Vegasmarc21]

Here is a video I took today. 1 year driving it like this. Ready to get it fixed. The video is dim, but you'll be able to hear the clunk metal knocking sound...I'm thinking the slip yoke is making that sound...it happens 3rd gear on up at a constant speed like 35 on up. Some days it doesn't happen, but that's is rare...anyone know what that sound Is? I honk a couple of seconds after I feel the shudder/vibration while I'm driving.

Here is the link

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Here is a link I found on YouTube that sounds like mine...what do you guys think?

 

[Big Mama]

I’d think it’s in the rear end. Can you move the yoke side to side by hand when stopped? If you’re under way you’ve got tension on the yoke unless you see your rpm go up suddenly due to slipping. Others with more rear diff experience will chime in.

 

[Vegasmarc21]

I’d think it’s in the rear end. Can you move the yoke side to side by hand when stopped? If you’re under way you’ve got tension on the yoke unless you see your rpm go up suddenly due to slipping. Others with more rear diff experience will chime in.

But if you watched the 2nd video, it's the same sound the slip yoke makes in the second video...kind of a knocking sound....i notice your Yukon is lowered, I want to lower my Tahoe too and im thinking it will line up the rear diff better. When you lowered yours, no extra work for your pinion angles?

 

[swathdiver]

Seems to me that your truck made those sounds when changing lanes or after a turn. Not so sure that is drive line. Sounds like a heat shield fluttering. Cool video btw.

Have you pulled the driveshaft and greased the slip yoke's splines?

The second video, that old driveshaft appears to be too short and he probably needed greasing as well. It's woefully out of round.

 

[Boatguy272]

Call me silly, but I think the second video clearly shows the driveshaft wobble,,,, that should be your vibration

 

[swathdiver]

Call me silly, but I think the second video clearly shows the driveshaft wobble,,,, that should be your vibration

That's not his truck, just a comparison.

 

[Boatguy272]

Ahhhhh,, thanks

 

[Vegasmarc21]

Seems to me that your truck made those sounds when changing lanes or after a turn. Not so sure that is drive line. Sounds like a heat shield fluttering. Cool video btw.

Have you pulled the driveshaft and greased the slip yoke's splines?

The second video, that old driveshaft appears to be too short and he probably needed greasing as well. It's woefully out of round.

Wow, you are very observant. Yes the heat shield does make a fluttering sound, usually on the highway making sweeping curve to the left...I have not greased my slip yoke, I can and will do so if it won't get grease in the transfer case like some people say.

 

[swathdiver]

Wow, you are very observant. Yes the heat shield does make a fluttering sound, usually on the highway making sweeping curve to the left...I have not greased my slip yoke, I can and will do so if it won't get grease in the transfer case like some people say.

Well, don't use too much and use the synthetic stuff called for in the owner's manual.

 

[Big Mama]

Sounds like Chris may have it if you’ve noticed the heat sheiks rattling before. About lowering I didn’t need to address pinion angle

 

[Vegasmarc21]

Sounds like Chris may have it if you’ve noticed the heat sheiks rattling before. About lowering I didn’t need to address pinion angle

Ok, but the heat shield vibrating I'm thinking is because of something making it vibrate, like u joints, slip yoke, unbalanced driveshaft, pinion angle, driveline phasing, and tires, wheel bearings, out out of alignment ring and pinion,

 

[Vegasmarc21]

Here is what I have observed after a year of driving:

1.Drives great first 5 to 8 minutes until reached operating temperature with no vibrations.

2. Someone installed new u joints before I purchased it, don't know how new, I bought it from a ford dealership.

3. Changed rear diff fluid (Mobil 1 syn with Lsd additive) and transfer case fluid (Mobil 1 and dexron vi syn blend)
>>>>drove really smooth for about 3 days after changing thinking problem solved <<<<<

4. Does not vibrate in 1 or 2nd gear.

5. Tires are 265/65/18 Goodyear ar-s 50% worn

6. Runs great wot 1 thru 6 gears

7. Runs pretty smooth with heavy cooler for camping and weighted down rear with passengers....(That's why I'm thinking lowering it would help and I like that look anyway....

8. No trouble codes over a year except showed running lean once

9. I try to wiggle driveshaft but there is no play....

 

[swathdiver]

Ok, but the heat shield vibrating I'm thinking is because of something making it vibrate, like u joints, slip yoke, unbalanced driveshaft, pinion angle, driveline phasing, and tires, wheel bearings, out out of alignment ring and pinion,

You forgot wind...

 

[Vegasmarc21]

You forgot wind...

Oh ya drives great with oncoming wind where I have to keep rpm's above 3k....

 

[swathdiver]

3. Changed rear diff fluid (Mobil 1 syn with Lsd additive) and transfer case fluid (Mobil 1 and dexron vi syn blend)
>>>>drove really smooth for about 3 days after changing thinking problem solved <<<<<

Mobil 1 and Dex VI in your transfer case???

 

[Vegasmarc21]

Mobil 1 and Dex VI in your transfer case???

Rear differential-
Mobil 1 75w90 synthetic with (limited slip additive included)

For transfer case-
Mobil atf dexron vi fluid

 

[thompsoj22]

imo, pull the drive shaft and you will find your problem. someone installing new u joins could have absolutely messed up pressing them in. slip joint dry, trans extension bushing shot.

 

[Big Mama]

Kinda goes back to it not happening under load of higher rpms keeping things tight. I agree with j22 pull the drive shaft and you’ll find it. You’re correct that it might be something causing the shield to rattle but see if you can secure it or remove it to see if any noise is there.

 

[Vegasmarc21]

Kinda goes back to it not happening under load of higher rpms keeping things tight. I agree with j22 pull the drive shaft and you’ll find it. You’re correct that it might be something causing the shield to rattle but see if you can secure it or remove it to see if any noise is there.

Keeping a tight spin under high rpms is right, that's what a driveline shop told me. Like spinning a top, when it loses speed, it wobbles. A guy working at advanced auto parts told me also when I'm accelerating hard, the vehicle will squat down and that's enough to correct a small pinion angle that's off. I have decided to drop it. I went to Auto Zone last night and bought Lucas Red N Tacky #2 heavy duty grease. It says it's good for sliding parts, but am scared as some say don't use grease as it will get inside the transfer case and mess up clutches???? What Do You think? Also, someone on offer up is selling a 2-4 drop kit (drop spindles and coil springs in back). Im thinking since i loaded up the rear with a heavy cooler and camping gear with passengers in back where the rear end was dropped down, it road really smooth that time.

 

[thompsoj22]

Transfer case? the video is of the rear shaft correct? imo, a moly paste/grease is better suited for your ap. The drive shaft spline really should need only a "light" application on install. it does exist in a wet environment as the tail housing bushing and the spline are lubricated by the trans fluid. Just be aware depending on the incline that you are parked when you pull the drive shaft there is a possibility of some auto trans fluid coming out. That much racket should have some slop evident even without removing the shaft. park the car level and chock the rear wheel so the driveline is "unloaded", Get underneath and see if you can see the yokes are worn by twisting the driveline cw/ccw. im guessing Its a u joint!

Also im a 59 year old "factory purist" so your venture into lowering is against my principals. But they do look cool when done right.