Driveshaft vibration video

[Vegasmarc21]

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.

Yes it's the rear driveshaft. So basically I should not use the Lucas heavy duty red n tacky grease to lube the splines? I have tried to move the driveshaft on level ground, and it won't budge, not even a little. The u joints seem to be new, but don't know how new since I bought it from a dealer used 1 year ago. Going to take it to a driveline shop today. One last thought or comment, when my tires are low like 30 to 31 pounds, it seems to not vibrate or chugged or much or not at all....it's wired because I'd bet the farm it's not tire related....I like all factory and keeping factory, but the rear is jacked up so high, maybe I'll drop it like the police vehicles are.

 

[swathdiver]

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.

Don't be skeered. Your owner's manual tells you to grease the slip yoke splines. These are trucks that are built for towing. They ride better by design with weight on the rear. It's not so much about being lowered as having weight in the back.

 

[Vegasmarc21]

Ha ha lol "Don't be skewered" is Lucas Red n Tacky #2 grade ok. It says it's good for sliding components okay to use? Or should I buy the motorcraft grease made for slip yokes. Link below is for fords but....https://www.google.com/shopping/pro...&ved=0ahUKEwjSgquMmbvdAhXD1IMKHVNtDJMQgjYI7wE

 

[swathdiver]

Ha ha lol "Don't be skewered" is Lucas Red n Tacky #2 grade ok. It says it's good for sliding components okay to use? Or should I buy the motorcraft grease made for slip yokes. Link below is for fords but....https://www.google.com/shopping/pro...&ved=0ahUKEwjSgquMmbvdAhXD1IMKHVNtDJMQgjYI7wE

No Ford grease! LOL

Red-N-Tacky is fine. GM calls for synthetic grease but plenty of folks use the Lucas with no ill effects. I have both.

 

[thompsoj22]

The second video is much more visible. That driveshaft has issues, remove it and inspect the inner splines, somthing is wrong there. Replace the drive yoke to shaft, they are cheap. Have new universal installed on both ends or do it yourself, but i think you should have the shaft checked for trusness/balance before install. These are simply guesses/opinions of how i would fix my own vehicle. Your shaft spline also seems to be "excessively extended under acceleration. Your ride height may actually have somthing to do with it, is it all stock in the rear?

 

[BeenChevy]

Funny. I noticed the same issue in one of my vehicles after the U-joints were replaced. Vibration at 30mph and again at 55mph. Haven't thought TOO much of it since I use that truck as a secondary but have put at least 20k on it like that and it hasn't gotten any worse. I hope you reveal the culprit as I won't have time to tear mine down anytime soon. Best of luck.

 

[Vegasmarc21]

I know it's been weeks since I started this post, but here is a new video of the slip yoke at the transfer case. Slip to the 4:52 Mark and 7:09 Mark is were you can see the vibrations I'm feeling. Anybody that knows what's going on chime in...

 

[BeenChevy]

The sound alone doesn't match what i'd expect to hear when looking at the vibration of the shaft. Pull your rear rotors and have a look at your parking brake components. This isn't too far fetched as I recently had a very similar vibration/sound in an 05 Tahoe and it was because the rear parking brake components where coming apart.

 

[Vegasmarc21]

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.

You are right! Finally pulled driveshaft yesterday and found the problem. I bought the Tahoe 1 year ago and u joints looked new but like you said someone pressed them in wrong because the rear ujoint was so tight(binding) and the slip yoke dry. So I tried to relieve some pressure on the rear ujoint, and could not really fix it to where it was any use....but I did grease the slip yoke, and removed the small layer of rust on exposed part of slip yoke, put back on and made sure to center the rear ujoint on to the rear diff (noticed that the driveshaft wanted to center itself a tad towards the drivers side rear wheel) so I bolted it back on making sure to guide the shaft on center....drove it and even though I need to still change rear ujoint for a new one, the Tahoe drove and felt so much smoother and actually seemed to shift better and felt only a very little soft vibration 1 time which I know when I get my new ujoint today will take care of any vibes on the driveline. But thanks to all comments, because they were all pretty much correct. "Pull the driveshaft and you will find your problem".

 

[bottomline2000]

View attachment 208280
You are right! Finally pulled driveshaft yesterday and found the problem. I bought the Tahoe 1 year ago and u joints looked new but like you said someone pressed them in wrong because the rear ujoint was so tight(binding) and the slip yoke dry. So I tried to relieve some pressure on the rear ujoint, and could not really fix it to where it was any use....but I did grease the slip yoke, and removed the small layer of rust on exposed part of slip yoke, put back on and made sure to center the rear ujoint on to the rear diff (noticed that the driveshaft wanted to center itself a tad towards the drivers side rear wheel) so I bolted it back on making sure to guide the shaft on center....drove it and even though I need to still change rear ujoint for a new one, the Tahoe drove and felt so much smoother and actually seemed to shift better and felt only a very little soft vibration 1 time which I know when I get my new ujoint today will take care of any vibes on the driveline. But thanks to all comments, because they were all pretty much correct. "Pull the driveshaft and you will find your problem".

If you hit the rear flat spots of the driveshaft with a dead blow hammer it will relieve the tension on the joint. U will feel it free up. Also, make sure you use new joint straps and torque bolts to spec..

You can do the same for the front yoke if the joint is stiff as well.

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[Vegasmarc21]

If you hit the rear flat spots of the driveshaft with a dead blow hammer it will relieve the tension on the joint. U will feel it free up. Also, make sure you use new joint straps and torque bolts to spec..

You can do the same for the front yoke if the joint is stiff as well.

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I tried to tap the spot you are talking about with a small hammer, but was scared to tweek the driveshaft. I think the retaining clips are too thick on that Spicer ujoint. Can I just remove the clips and sand them down a little to relive the tight binding? I guess I should try before getting a new one wouldn't hurt. The front ujoint on the slip yoke feels ok. I went to Napa and got new bolts because one of the bolts got rounded by who ever put those u joints in before and the Napa guy hands me a box with new bolts and straps, so I used the new straps.....

 

[bottomline2000]

I tried to tap the spot you are talking about with a small hammer, but was scared to tweek the driveshaft. I think the retaining clips are too thick on that Spicer ujoint. Can I just remove the clips and sand them down a little to relive the tight binding? I guess I should try before getting a new one wouldn't hurt. The front ujoint on the slip yoke feels ok. I went to Napa and got new bolts because one of the bolts got rounded by who ever put those u joints in before and the Napa guy hands me a box with new bolts and straps, so I used the new straps.....

I used a dead blow hammer on mine and it didn't tweak it. It takes a certain amount of force to move that joint. I'm not gonna tell u to do it, but I filed down my clips in my yoke because they were too tight. I would make sure the clips are the problem and not just tension on the joint needs to be relieved. I have a hybrid ujoint due to my 4l80 trans with a 1350 yoke that uses the same clips. I tried different sizes and everything. Only fix was to sand them down slightly. Been running like this for about a year.

The torque specs are not that high for the straps so I wouldn't be surprised if they were on too tight if the bolt was rounded. I would not reuse them if you take them or the bolts off..they are stretch fit.

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[Vegasmarc21]

I don't have a torque wrench, I know I need to get one, but I torqued them down tight....maybe I should back off a little. The damn bolts that cam with the straps Are about 1/4 inch longer than what was on there before and had to really crank down on the bolts to get it tight....i need maybe to put a washer to take the space up....i should go back to Napa and tell them the bolts are too long. But thanks, good info, because I probably might have over tightened....its the first time doing this for me....infact my driveway has a very small incline, before my wife left for work I told her to step on the e brake...when I dropped the driveshaft the Tahoe started rolling and had to grab the rear swaybar to hold it. Luckily a neighbor's friend pulled up and I called him over to step on the e brake....kinda scary....

 

[Vegasmarc21]

I used a dead blow hammer on mine and it didn't tweak it. It takes a certain amount of force to move that joint. I'm not gonna tell u to do it, but I filed down my clips in my yoke because they were too tight. I would make sure the clips are the problem and not just tension on the joint needs to be relieved. I have a hybrid ujoint due to my 4l80 trans with a 1350 yoke that uses the same clips. I tried different sizes and everything. Only fix was to sand them down slightly. Been running like this for about a year.

The torque specs are not that high for the straps so I wouldn't be surprised if they were on too tight if the bolt was rounded. I would not reuse them if you take them or the bolts off..they are stretch fit.

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That looks so clean and a precision set up...btw, can I remove the clips on the vehicle to sand them down?

 

[bottomline2000]

That looks so clean and a precision set up...btw, can I remove the clips on the vehicle to sand them down?

It would be a lot harder determine if the yoke was free or bound up with the driveshaft installed. I used a press to move the yoke from side to side and carefully sanded down both clips to equally free up the space needed. I've taken my truck on road trips and upwards of 130mph so I didn't take this mod lightly. If you don't feel comfortable doing it take it to a driveshaft shop and let them do the install.

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[Vegasmarc21]

It would be a lot harder determine if the yoke was free or bound up with the driveshaft installed. I used a press to move the yoke from side to side and carefully sanded down both clips to equally free up the space needed. I've taken my truck on road trips and upwards of 130mph so I didn't take this mod lightly. If you don't feel comfortable doing it take it to a driveshaft shop and let them do the install.

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I guess I'll drop the driveline again. If I have to buy a new ujoint, do I have to match the u joint on the slip yoke side? The ones I have now are Spicer with the zerk fitting.

 

[bottomline2000]

I guess I'll drop the driveline again. If I have to buy a new ujoint, do I have to match the u joint on the slip yoke side? The ones I have now are Spicer with the zerk fitting.

U shouldn't have to buy a new joint. U just need to figure out why it's binding. You can buy just the clips because they have a fatigue point where they should be replaced if you flex them too much. Mine are different because of my drivetrain change. Your clips should be the same on both sides unless you factory joint is a hybrid joint. A couple of heavy taps on the yoke and flat spots on driveshaft may free up the joint and you are good. No need to mess with the clips.

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[Vegasmarc21]

I went to my father in laws auto repair shop and took the drive shaft out. Showed how binded and tight the rear u joint was. He told me to rest the u joint on the clamp and tap the bottom of the ears and it was a smooth rotation. Put the clips back on which looked like they were wedged to one side in the grooved when I took them out, and then installed driveshaft back on...45 min job because I took my time.

 

[bottomline2000]

I went to my father in laws auto repair shop and took the drive shaft out. Showed how binded and tight the rear u joint was. He told me to rest the u joint on the clamp and tap the bottom of the ears and it was a smooth rotation. Put the clips back on which looked like they were wedged to one side in the grooved when I took them out, and then installed driveshaft back on...45 min job because I took my time.

Yessir! That's what I meant. Glad to see it worked out.

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