Shake or Vibration Issues

14silverado4.3 · September 18, 2015

http://wjla.com/news/local/owners-of-best-selling-2015-honda-cr-v-complain-of-vibration-problems-111800

Anyone close to this news agency? Sheesh they only have 600 comments and 83,000 views... our forum would kick their ass!

abominable z71 · September 18, 2015

OK, GM gurus, engineers, mechanics:

What changes when going up inclines or declines at highway speed?

If running cruise, the engine is going to dump gas into it to maintain speed.

What other things change on not level?

Weight distribution from the front to rear wheels will change with the slope you're on. On flat ground all of the vehicles force (weight) is vertical. The normal force which is the force perpendicular to the road and the vertical force are the same and the vehicles weight contributes no force in the horizontal direction. As you tip it up on an angle the vehicles weight creates two forces one vertical and one horizontal and the normal force is reduced in relation to the angle of the grade (vehicles weight x cos(angle of the hill)). The steeper the grade the lower the normal force, this is why the steeper the hill is, the easier it is to slide down (friction coefficient times normal force, no normal force, no friction). In order for your truck to not slide backwards due to this new horizontal force it creates a moment about the rear. What this has done is effectively moved more force into the rear springs causing them to compress further add acceleration into the mix and some axle wrap and your pinion flange rotates up. Get on the brakes going down hill and you will have the reverse case but even more exaggerated because the truck is already front heavy.

14silverado4.3 · September 18, 2015

OK not a mechanic but what in the pinion flange would vibrate as it rotates up or down?

14silverado4.3 · September 18, 2015

How would I know if I have a worn transmission mount?

Transmission mounts give off many possible signs that they are weak or wearing. The first may be an awkward "clunk" or metal creaking sound when you change gears. This may or may not be accompanied by a jolt or what feels like a transmission slip when you switch gears, especially from park or reverse to drive and vice versa. While driving, a worn transmission mount can also cause what is known as "chatter" which is similar to a rumble or shaking in your drive train. Some drivers also experience body roll or shifting of the vehicle weight going around corners. Finally, you'll want to look out for a tweaking or twisting of your frame under strong torque or with high rpm's. Your frame will most likely not be twisting, but it may feel that way and would typically be accompanied by creaking noises.

Read more: http://www.redlinemotive.com/replacement/transmissionmount.asp#ixzz3m7N6XbvS

abominable z71 · September 18, 2015

OK not a mechanic but what in the pinion flange would vibrate as it rotates up or down?

Improper working angle causes the drive line to speed up and slowdown 4 times per revolution to account for the u joint angles not cancelling each other out on both ends, out of phase drive shafts will cause the exact same problem even without the pinion shaft rotating up or down.

This video is worth a thousand posts:

SinisteRR · September 18, 2015

RESOLUTION:

I got my truck back today from the dealership after they had it for two days. They road force balanced the tires, and found that a front one had too much weight on it, 5oz too much from the factory. They also found a bent rim. Now, I am fairly confident that i did not bend the rim. At this point, it seems as if the vibration is gone, but i need to drive it on the highway more, which i haven't had a chance to do very much.

He did mention that this is the first time they have seen this and would be looking for another truck to do these tests to. They also talked about this new road force balance machine that took a lot of skill to use correctly. in fact they trained a lot of techs on it with my truck. The truck feels better than it did when i got it. Hopefully this helps someone, however it seems that people are having bigger issues than simple tire balance.

My dealer is Lafferty Chevrolet in Warminster PA. The service manger is Johnny and he is spectacular. I got the impression that alot of the equipment he used to diagnose it was new and just getting in use. I can't say enough good about this dealer, they dove head first into this issue and at this point, did a great job.

Jesse Davidson · September 19, 2015

RESOLUTION:

I got my truck back today from the dealership after they had it for two days. They road force balanced the tires, and found that a front one had too much weight on it, 5oz too much from the factory. They also found a bent rim. Now, I am fairly confident that i did not bend the rim. At this point, it seems as if the vibration is gone, but i need to drive it on the highway more, which i haven't had a chance to do very much.

He did mention that this is the first time they have seen this and would be looking for another truck to do these tests to. They also talked about this new road force balance machine that took a lot of skill to use correctly. in fact they trained a lot of techs on it with my truck. The truck feels better than it did when i got it. Hopefully this helps someone, however it seems that people are having bigger issues than simple tire balance.

My dealer is Lafferty Chevrolet in Warminster PA. The service manger is Johnny and he is spectacular. I got the impression that alot of the equipment he used to diagnose it was new and just getting in use. I can't say enough good about this dealer, they dove head first into this issue and at this point, did a great job.

you're lucky

pm26 · September 19, 2015

RESOLUTION:

I got my truck back today from the dealership after they had it for two days. They road force balanced the tires, and found that a front one had too much weight on it, 5oz too much from the factory. They also found a bent rim. Now, I am fairly confident that i did not bend the rim. At this point, it seems as if the vibration is gone, but i need to drive it on the highway more, which i haven't had a chance to do very much.

He did mention that this is the first time they have seen this and would be looking for another truck to do these tests to. They also talked about this new road force balance machine that took a lot of skill to use correctly. in fact they trained a lot of techs on it with my truck. The truck feels better than it did when i got it. Hopefully this helps someone, however it seems that people are having bigger issues than simple tire balance.

My dealer is Lafferty Chevrolet in Warminster PA. The service manger is Johnny and he is spectacular. I got the impression that alot of the equipment he used to diagnose it was new and just getting in use. I can't say enough good about this dealer, they dove head first into this issue and at this point, did a great job.

5 ounces too much from the factory on one wheel? Are you kidding me? Even 1 ounce out total will cause very noticeable vibration at high speeds. Who balances the wheels at that factory? Looks like someone just slapped on 3 oz worth of weights in the wrong position on the wheel to give it that much imbalance. But I wonder if they balanced those wheels right at the dealership too.

If I saw that a passenger car/truck wheel is out by 5 ounces I would immediately suspect that the tire or the rim is junk or someone really just slapped on some weights to make it look like they balanced the wheels.

Is this a chrome clad wheel? If yes, you should never cone the wheel in the front on the balancer, otherwise the cone will catch the cladding first and not center the wheel properly. Rear cone of collet, plus rubber protected pressure cup wing nut is the least acceptable. Rear mounted spacer, collet plus a flange plate in the front would give the best results. Collets are simply short centering sleeves with very low taper, and they are frequently used on high end cars like Mercedes and BNMW for proper balancing, together with Haweka flange plates that hold the wheel by the lug nut holes.

Here is a COUPLE OF short videos showing use of Haweka flange plates to achieve the best balancing results:

As you may have noticed, the balancers in the video do not have road force variation measurement capability. Zeroing on only on reducing road force variation numbers and using inferior mounting techniques will not produce good balancing results. On the other hands, using good quality tires and properly balancing them will more than likely produce very good results without measuring the road force variation. Unfortunately many techs out there simply think that there is some magic in measuring road force that will be a cure-all for all vibration problems. There is no substitute for proper mounting technique and high quality components used with the balancers. BTW, Haweka products are German made. I do not have any affiliation with that company and I do not sell any wheel balancing products. I am merely recommending what is the best on the market in my opinion. Because of high cost of high end products like these, not too many tire shops carry them. A set of adjustable Haweka plates alone costs about $ 3000. Then about $ 1000 for a decent set of collets. For comparison, a regular cone set is about $ 250 per set of four, plus about $ 250 for a good quality pressure cup wing nut and most tire shops will therefore use the traditional cones only.

Edited September 19, 2015 by pm26

fireaxxe · September 19, 2015

Balanced the tires, replaced entire exhaust, slight vibration still there. The vibration had an oscillating character mostly going uphill slightly and slowing down from 50-40mph. A sure sign that I had driveline misalingment issues was the grease leaking at the front u-joints. I started experimenting with pinion/transmission output shaft angles. I notice there is alot of tolerance through the frame and attachment points. I adjusted the transmission by backing off the four bolts that attach the trasmission crossmember to the frame and was able to raise this with a jack by 1/4". This decreased the working angle of the front u-joint by .2 degrees. I then bought 2* degree wedges for the rear axle and rotated the pinion up. This made the vibration worse and gave me a bad vibration when accelerating. I removed the wedges and bolted everything back up set the u-bolts to 75 lb ft. torque and went to get the alingment checked because the thrust angle had changed. To my surprise on the way to the shop I noticed all vibrations were totally gone.

When I got it on the alingment rack my thrust angle had gone from +.20 to -.09. This effectively changed the pinion angle and must have put it in the sweet spot putting the rear u-joint in phase with the front u-joint. I am very happy now that this is figured out. I think this issue is a collective issue like I said. But I think the majority of what is causing these vibration issues is drive line misalingment. I hope this helps.

20L8TSierra24 · September 19, 2015

RESOLUTION:

I got my truck back today from the dealership after they had it for two days. They road force balanced the tires, and found that a front one had too much weight on it, 5oz too much from the factory. They also found a bent rim. Now, I am fairly confident that i did not bend the rim. At this point, it seems as if the vibration is gone, but i need to drive it on the highway more, which i haven't had a chance to do very much.

He did mention that this is the first time they have seen this and would be looking for another truck to do these tests to. They also talked about this new road force balance machine that took a lot of skill to use correctly. in fact they trained a lot of techs on it with my truck. The truck feels better than it did when i got it. Hopefully this helps someone, however it seems that people are having bigger issues than simple tire balance.

My dealer is Lafferty Chevrolet in Warminster PA. The service manger is Johnny and he is spectacular. I got the impression that alot of the equipment he used to diagnose it was new and just getting in use. I can't say enough good about this dealer, they dove head first into this issue and at this point, did a great job.

Glad to hear

Sent from my SM-G920V using Tapatalk

abominable z71 · September 19, 2015

Balanced the tires, replaced entire exhaust, slight vibration still there. The vibration had an oscillating character mostly going uphill slightly and slowing down from 50-40mph. A sure sign that I had driveline misalingment issues was the grease leaking at the front u-joints. I started experimenting with pinion/transmission output shaft angles. I notice there is alot of tolerance through the frame and attachment points. I adjusted the transmission by backing off the four bolts that attach the trasmission crossmember to the frame and was able to raise this with a jack by 1/4". This decreased the working angle of the front u-joint by .2 degrees. I then bought 2* degree wedges for the rear axle and rotated the pinion up. This made the vibration worse and gave me a bad vibration when accelerating. I removed the wedges and bolted everything back up set the u-bolts to 75 lb ft. torque and went to get the alingment checked because the thrust angle had changed. To my surprise on the way to the shop I noticed all vibrations were totally gone.

When I got it on the alingment rack my thrust angle had gone from +.20 to -.09. This effectively changed the pinion angle and must have put it in the sweet spot putting the rear u-joint in phase with the front u-joint. I am very happy now that this is figured out. I think this issue is a collective issue like I said. But I think the majority of what is causing these vibration issues is drive line misalingment. I hope this helps.

Fire,

Did you measure the working angles for the rear drive shaft before making the adjustments to the transmission and adding the wedges? If so what were they, I'd like to compare them to mine. My working angles were 1.6 down in the front and .6 down in the rear. I added 2 degree shims in theory that should roll the pinion up to have a working angle of 1.4 up almost zeroing out but it didn't seem to affect the vibration much, I still need to measure the angles to see what affect they actually had. Thrust angle might still have the u joints out of wack, something to look at, I also got grease leaking from every cup on both u joints, the underside of the body is speckled with grease. Time to make an appointment with the alignment shop and check the thrust angle. Glad I sprung for the lifetime alignment.

peejaykay · September 19, 2015

Got mine in the shop yesterday. They determined that it's not the wheels/tires, and instead somewhere in the driveline (using some vibration sensors). They looked at the propshaft and said it seems like I have some scratches, so they think that's causing the vibes. I called BS because I brought the truck in with 1100 miles on it with the vibe issue, same problem. So I'm concerned that they will charge me for a new driveshaft even if the old one is out of spec. I'll ask them to prove to me that my my owner caused "scratches" are causing the vibes. Because they're not. It's probably just a tumbleweed or something that superficially scratched the driveshaft and not anything significant.

The tech said more than like likely its the pinion gear though. So more to come.

fireaxxe · September 19, 2015

Fire,

Did you measure the working angles for the rear drive shaft before making the adjustments to the transmission and adding the wedges? If so what were they, I'd like to compare them to mine. My working angles were 1.6 down in the front and .6 down in the rear. I added 2 degree shims in theory that should roll the pinion up to have a working angle of 1.4 up almost zeroing out but it didn't seem to affect the vibration much, I still need to measure the angles to see what affect they actually had. Thrust angle might still have the u joints out of wack, something to look at, I also got grease leaking from every cup on both u joints, the underside of the body is speckled with grease. Time to make an appointment with the alignment shop and check the thrust angle. Glad I sprung for the lifetime alignment.

Engine/Trans angle +4.5 degrees, driveshaft +3.5, and pinion angle was -2.6 degrees. The 2 degree put the angles amost exactly the same but this increased the vibration during the acceleration due to the fact that the pinion rotates up when you hit the gas. I did not expect it would be that much. So rotating the pinion angle up to a +0.0 angle will not help at all.

pm26 · September 19, 2015

Are you checking the pinion shaft nut for proper torque? If not tightened properly, this will cause improper preload on the pinion shaft bearings, lateral movement of the shaft under load, and all kinds of issues with pinion and ring gears in your rear differential.

JasonSilverado · September 19, 2015

I too have the issue on my 2015 LTZ Crewcab. Had it for a couple of weeks. First time it went in they rotated and balanced the tires. Picked it and noticed not much changed. Took it back last week they road force balanced the wheels and tires and replaced three of the tires as a result. Condition is improved but not gone by any means. Started to think it was just me as I've only had cars for quite awhile. Took it back this week after chatting with my sales guy and and he took it for a drive and confirmed it wasn't just me. He spoke to the Service Manager on my behalf and it will go back in on Tuesday when he said they will get the GM engineers involved. I'm cautiously optimistic since they seem to be truly concerned with getting the issue resolved.