I come here bc ive not recieved any logical assistance from the silverado/sierra forum, but my question is, how tight should the tolerances be on the front cv axles? I know on most it should so minimal you shouldn't visually see it or feel it let alone hear it... I drive an 07 nnbs sierra z71, so how sloppy are the tolerances on the CV axles for these trucks?
Question, how much should I be able to rotate my front cv axles on my 07.5 nnbs z71 sierra? That's with it in park, on flat ground, with the emergency brake set. How much should I be able to rotate the shaft back and forth?
I know this is an older post. But I was curious as to the vibration you had that the struts fixed. I'm having a vibe in my 07.5 nnbs and I've replaced the u joints, upper control arms, front end alignment, had the driveshaft checked and new u joints installed, also have brand new 265 70 17 all terrain tires. And I'm getting a vibe that starts around 55ish and doesn't go away. Doesn't get worse just persists... smoother roads its not as bad, but older roads it's pretty rough. Almost feels like driving down a gravel road constantly...
I've been seeing and hearing alot about the oem axles that gm uses being junk due to the flange actually being out of round to the point of being more of an oval. My question is how many people have experienced this and it actually be causing a vibration that doesn't go away?
Yeah, I've changed everything that was loose or needed to be changed except the drums, but I got new ones on the way, bendix brand and machined and balanced perfectly. New tires, they are all within specs, 2 new u joints installed when I had the driveshaft checked(he said it was perfect) new moog upper control arms, front end alignment. Driveline angle seems to be in spec if I measured right. New engine mounts bc they were destroyed. But everything changed when I clocked the drum 1 stud.
Another update, I jacked up the rear of the truck the other day and removed the right rear wheel and ran it in gear and watched the drum itself. I know the drum isn't perfectly machined so I didn't pay a whole lot of attention to the out of round on the rear part of the drum and the crappy castings causing it not to be true all the way around, I removed the drum and clocked it one stud hole to the right and reinstalled, the vibration is now better at higher speeds but still tho, also it's now way more noticeable at low speeds, plus while running it in gear up in the air you can hear the pads catching a low spot on the drum. Also, the low speed vibration that more noticeable its ONLY when I first drive it... like when everything is cooled off...
Did you ever figure out your vibration? I have a level kit on my truck and im getting a mild vibration at highway speeds as well... with brand new 265 70 17 tires.
So took the driveshaft to the driveline shop today, he said the driveshaft was fine, only had .010 run out and wasnt out of balance. But he did install 2 new Spicer greaseable u joints for me. So if that doesnt fix it then I'm back to the drawing board... Could the level kit up front be enough to disturb the driveline angle on the slip yoke u joint??
I've replaced the engine mount already, done that this past weekend. And there wasnt any signs of any fluid leaking from then either. I figured it got worse with the load due to changing the angles of the u joints slightly combined with the already existing issues. But... then again that's why I'm here. Bc I dont know.
A little bit of an update, yesterday after work I hauled a complete 4.8 engine block for a buddy at work and with the wieght of that engine in the bed of the truck it made my vibration worse. Didnt seem to change the frequency, just made it worse. So I'm figuring with that it may be something in the driveline...
So after work I got home and jacked up all 4 corners of the truck spun and checked for any out of round on the wheels. One wheel seemed to have a little bit on the outer edge but nothing to extreme, even swapped my spare with that rim and went for a drive, no difference. So I jacked up the rear of the truck and let it idle in gear and watched as my driveshaft spun, towards the front where it slips into the transmission I could actually see a small amount of run out and could even feel if I let my fingers lightly rest on it as it rotated, if I slid my fingers down to around the center of the driveshaft the feeling almost went away. Being that maximum driveshaft run out is .005 to .010 one would think you couldn't see that with the naked eye. So my next step is to set up an appointment at a driveline shop about an hour from me and have the run out checked and balanced as well as new u joints. Sure hope that's the issue, I do love this truck.
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