Just had Driveshaft Balanced... (((Chevy Shakes Vibriation)))

FL335i · December 20, 2017

And a good afternoon to all! I finally got around to finding a local drive shaft shop in Tampa and decided to pull my rear shaft for a balance. I bought my truck brand-new in late 2014 and have had a slight 75-80mph rear-end vibration on the highway. Compare to others with the Chevy shakes mine is mild. I got a hold of the vibration TSB about 1yr ago and went through and measured my shaft per the TSB. Per the TSB, my shaft met spec for run-out. Well I pulled the shaft, took it to Driveshaft Specialist. Picked it up about 2hrs later. It was out of balance. On the front section the one stock weight was removed and nothing added. On the rear the one stock weight was removed. A larger weight was placed roughly 45 degrees from the OEM location. I have pictures of all this, and will post them. I put the shaft back in and need to take it out for a test drive tomorrow. I also had them replace the U-joints while the shaft was out and being I have 75k miles on my truck. Funny thing is mine was not the only K2XX driveshaft in their shop. I saw another one on the rack ready for pick up. The shop guys spotted me walking in and knew it was 'another Chevy shake shaft'. They had one on the floor was so out of spec they could not repair or balance it. I guess I got lucky mine was just out of balance. Can't wait to take it out for a highway ride! I will definitely post an update ASAP. Pics should be uploaded tonight. If this corrects or makes a noticeable improvement to my vibration these guys just made my Christmas.

Edited December 20, 2017 by FL335i

1badtie · December 21, 2017

pics.

FL335i · December 21, 2017

Pics....

Edited December 21, 2017 by FL335i

hirdlej · December 21, 2017

Why not try it tonight? C'mon man, we want to know how it worked out.

FL335i · December 21, 2017

Ok results... I took the truck out on the highway today for a bit. It's a lot better, but I still have a slight 75-80 vibration. It helped enough to where I can now cruise at 77 and live with it. The vibration at 75-80 has changed though now since the balance. The truck feels like it's running smooth and maybe a wheel is out of balance now. Before it felt like the entire truck was shaking like a paint shaker. the vibration still feels like it's coming from the rear axle. If AAM makes their axles like they balance their driveshafts, that probably explains it. I'm not sure this is ever going to be fully corrected. That's probably why Gm only ran the K2XX platform for 4yrs, lets be honest. it's probably inherent in the frame design. So there you have it. yes it helped. Is it a silver bullet fix? No.

Edited December 21, 2017 by FL335i

hirdlej · December 22, 2017

It's probably only one of the compounding issues. If the driveshaft is perfectly balanced now, it's down to differential or tires/wheels. Let me ask you this, have you put the truck on jackstands, taken the wheels off, reinstall lugnuts and run it up to 75-80 on jackstands? It should be perfectly smooth. If not, you have something in the differential out of balance or possibly even the transmission. Put it on jackstands, remove tires, reinstall lugs and run it up to speed and tell us what it's like.

FL335i · December 22, 2017

Have not done that. I'm not doing that from a safety perspective. I witnessed my tires get balanced on a Hunter 9700. My tires had 20k on them when RF balanced the day after thanksgiving last month. I have E load, heavy 10 ply tires, 65lbs each IIRC. My RF numbers were up there, but we could not get them any lower. 25 Lbs of road force was about average for my tires at 40psi. I'm sure if I had a P rated OEM type tire that weighs 35lbs, and road forced to the GM spec of 15 Lbs of road force or less i'd be even better. But my BFG's are super smooth at all speeds except 75-80. And we've balanced them twice, once when new by shop A, on a regular spin machine and then 20k miles later on the Hunter 9700. So both balances on the BFG's and the factory SRA's all had a 75-80mph vibration.... think not. It's probably a rubbish axle. Hell, the RR axle is 'sweating' gear oil and had the seal replaced at 16k when it dumped gear oil out. I'm betting it's garbage axle shafts. But yes, you are correct we are dealing with a 'compound issue'. GM's manufacturing and supply houses are not up to the level of precision required for the level of truck they tried to build. I'd be curious if we put a 14 bolt rear axle in, would it do the same thing. I'm going to pull my shocks and see if they are worn out or if they have any dead band. Heck, i'm begining to wonder if it's the leaf spring bushings. Would a Energy Suspension bushing kit do anything?

I found a few you tube vids showing the axle flanges ans how out of round they are. Some of the comments state that they replaced their stock shafts with Yukon shaft and it corrected the vibration issues for them.

Edited December 22, 2017 by FL335i

Rukus · December 22, 2017

I had a 2015 LT 1500 and was smooth as can be. Midnight edition. Stock everything... 18" Duratrac... No issues 70-80 MPH. That ws until I had lost a weight on a tire. Then it shook like it was its job!!! WOW. Of course a little weight will give SOME vibration. But, this was CRAZY. I had re balanced... and I still had some vibrations... this was caused to tire wear. I contribute this to the frame "amplifying" the vibration. It was certainly for the rear. Acts like a tuning fork. I now have a 2017 and the vibration was there from day 1. Came with 2" lift and 20" rims. Horrible vibrations... I swapped shocks. No luck. Maybe 10% better. I then got a set of stock 17" for a friends WT that had about 800 miles on it. Ran it all the way to 90. (speedo of course off a little) 90%+ of vibration gone. I then grabbed a set of 18" with SRAs from dealer to test out theory. Defiantly had some vibration but a lot less than the 20". I RF'd the 20" and confirmed alignment dead on. I drove a payed extra attention to road service. I am good @ 75 until I hit a little groove or rough patch. Then vibration is there until I stop. Again, like a tuning fork. Summery: I think the frame amp up any outside forced vibration it comes across. Wider tires cause more vibration, heavy tires etc... then the frame Amps up those vibrations. OR... its all in my head.

20165.3Eco · December 22, 2017

How loose does your driveshaft yoke feel when it comes to lateral movement in the transfer case tail shaft? My Ram had a vibration at that speed that was the sort of rummm rummm rummmm type of pulsating vibration. I checked several other trucks which had minimal to no movement up down or side to side in the trans yoke 2 and 4wd alike. I checked everything possibility on my truck and that was the only spot I could pinpoint anything out of spec. I traded before I fixed it. I have a similar vibration in my 67 Plymouth and have also had everything replace/balanced/checked besides that output bushing. I am thinking that is my source for both vehicles being that it's the only point that appears to be out of spec.

I think I wore that out in the Ram because the drive-line spent a considerable amount of its life out of alignment (suspension compressed with loads/trailers)(they squat a lot when loaded). No other truck I checked no matter the miles had any play in the shaft yoke. Earlier in its life the truck was smooth as silk at all speeds so it was a wear related issue.

My 16' Silverado is smooth as silk. When it had the stock junk Goodyears on it I got a lot of bouncing over bumps and lots of road vibration through the steering wheel. Swapped out to new Bridgestone Alenza HL Plus and it's like a completely different vehicle. No more bounce over bumps, rides smoother, silky smooth as far as vibration goes, no longer terrifying in the rain. I was a little frustrated with the steering wheel vibrations but I accepted it. Immediate change when the new tires were installed.

Edited December 22, 2017 by 20165.3Eco

FL335i · December 23, 2017

I'll check the T-Case output shaft for any kind of play. When I re-installed the shaft I did not notice anything out of the ordinary though.

FL335i · December 24, 2017

Did a 200 mile highway trip today with the family. I got to vary my speeds all over the map. The vibration is considerably better with the shaft balanced. My wife was very happy today on the ride. In the lower 70's it's like glass. 75+ is when you start to feel it, but it's still way better than before. The truck is usable now. I'm not done tinkering with the vibration.... I think I'm going to forgo doing the Detroit locker and just do the Yukon shafts so it's a simple in and out type job vs setting up gears and switching the gears to the Detroit carrier. I already have the G80 and it works fine. I have no plans on running bigger tires.

Grumpy Bear · December 24, 2017

The guy the welded these weights on needs a beating.

Edited December 24, 2017 by Grumpy Bear

FL335i · December 26, 2017

Grumpy bear, I was questing the positioning and welding of this also. I'm not a driveshaft expert, but the weight has a contour. I thought it would be positioned to contour the shaft. Care to elaborate your comment please?

Edited December 26, 2017 by FL335i

Grumpy Bear · December 26, 2017

56 minutes ago, FL335i said:

Grumpy bear, I was questing the positioning and welding of this also. I'm not a driveshaft expert, but the weight has a contour. I thought it would be positioned to contour the shaft. Care to elaborate your comment please?

Me either but I do weld and I have had shafts balanced. Your instinct is correct. Should follow the curvature. Balance isn't just about getting the right weight. It's also about getting the right distance. In addition there is a reason they are 'buttonhole' welded. The weld has mass that has to be accounted for before it's welded on. Find a place that builds shafts for "V-drive" competition boats. Those boys will tell you that a shaft that is straight rarely needs to be balanced. So first they straighten them, then they balance them. They are all less than straight.

This guy looks like he believes MIG is the only welder on the planet and he hasn't learned to use it yet. Makes me wonder what other skills he's selling that he hasn't mastered yet. Just because the factory cobbled on the yokes with a MIG doesn't make it the right tool for the job. Just the fastest, easiest and cheapest. It the reason they need rework straight away.

You just can't buy good help these days.

Edited December 26, 2017 by Grumpy Bear

FL335i · December 28, 2017

Agreed grumpy bear. I find it very hard to find good skilled shops in Tampa. As you can see... The last time I had a Toyota shaft balanced by another shop in town, back in 2007. They did a crap job also. I'm 0 for 2 to find a good shaft shop in Tampa.