Spring Clamps Reduce Rear Vibration

[oneandzero]

I had a look at mine today and found the same as others around 40 ft/lbs so I re-torqued to 85. I can't say if it helps or not. I almost want to say it made the ride worse but I still have snow tires on and the weathers warming up so hard to tell.

Thought I would add a link for u-bolt torque specification because I was curious what it was supposed to be.

https://www.autoandtrucksprings.com/pages/U-Bolt_Torque.html

After driving to work this morning I have verified this has made it worse.

[Ron.s]

I agree, don't understand it but tightening the U bolts make the ride worse. So I removed my spring clamps and think it may be more normal now. Will test for a while and post again. Could it be that the U bolts being loose are some or all of the problem? In my case I don't believe my Magneride shocks are working properly.

[oneandzero]

I agree, don't understand it but tightening the U bolts make the ride worse. So I removed my spring clamps and think it may be more normal now. Will test for a while and post again. Could it be that the U bolts being loose are some or all of the problem? In my case I don't believe my Magneride shocks are working properly.

I've been contemplating putting mine back to 45ish but I guess you are supposed to replace u-bolts after tightening them once. I'm getting the 22s back on today so I'll see how it rides and go from there.

[Ron.s]

I've been contemplating putting mine back to 45ish but I guess you are supposed to replace u-bolts after tightening them once. I'm getting the 22s back on today so I'll see how it rides and go from there.

You might check but it's my understanding that it's the threads on the nuts that can stretch, so maybe just need new nuts. Also depends on how close to maximum torque-if you are 10-20 lbs under max then you probably didn't stretch the threads. A compromise to be 100% safe would be to double nut.

Edited March 22, 2016 by Ron.s

[DanY]

You might check but it's my understanding that it's the threads on the nuts that can stretch, so maybe just need new nuts. Also depends on how close to maximum torque-if you are 10-20 lbs under max then you probably didn't stretch the threads. A compromise to be 100% safe would be to double nut.

When doing the TSB for rear end clunk on my truck, the dealer replaced both the U-bolts and nuts. I have the part numbers if anyone needs them.

 

BTW, this did not fix my clunk, which seems to be getting better as the weather warms up. It seems that lifting the truck, ie unloading the springs, tends to help with the clunk.

[Ron.s]

OK, just completed a long trip retracing a route I took in February. I removed my spring clamps after finding the ride was worse after tightening the U bolts on leafs. Now my truck is almost normal, thinking that the loose U bolts were most of the issue. The vibration on rough roads is gone but now I can tell that the Magneride shocks aren't working correctly. There is little damping if any on small bumps and rollers I get some sway that I didn't have on my 14. I'm going in to the dealer and will see what they find.

[GMCSierra4x4]

I am less inclined to believe that the leaf springs are influencing the vibration since shocks are the primary method of dampening. It may be possible that the pinion angles are off which is somewhat corrected by clamping the leaf springs. Most of the posts favor clamping the springs in the front of the axle which would increase the pinion angle.

[hotrodz37]

I just completed a 400 mile trip this weekend with the clamps in front of the axle. Softened the ride some which is nice but definitely did not do anything for the vibration. If anything maybe slightly but certainly not enough that it's acceptable. My next step is going to be ordering shims to see if it is perhaps the pinion angle. Will keep y'all posted!

 

 

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[KLRV6]

I just completed a 400 mile trip this weekend with the clamps in front of the axle. Softened the ride some which is nice but definitely did not do anything for the vibration. If anything maybe slightly but certainly not enough that it's acceptable. My next step is going to be ordering shims to see if it is perhaps the pinion angle. Will keep y'all posted!

 

 

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I ordered shims which should be delivered this week. My truck is going on it's third week now and they aren't any closer to identifying the vibe problem. I tolerate delays, but the slowness between the dealer and GM is maddening. They take some measurements and send them to GM a few days later, GM responds with next steps and so on. Minus the transmission making a whining noise, failed weld on one of the converters, the remaining issues are small. The Vibration and trans problems are enough to start talking to their toyota friends down the street who would be more than happy to sell me a Tacoma. The funny thing is i am the only person who has hope about the vibe going away. My wife wants the Silverado gone and replaced with something comfortable which is what I thought I bought, but 1500 miles later things changed for the worse.

 

I too think the clamps are adjusting the angle as well as preventing some resonance within the spring set.

 

I'll make a vid and post of the shims driving post install. I already have one as it is now. Spicer has an online angle calculator http://spicerparts.com/calculators/driveline-operating-angle-calculator that helps with specific numbers. I used my digital angle gauge and put them in the web site. The shim information is located in GM document number 4072382 PI1354B Feb 5, 2015 starting on page 8. I am attaching my numbers.

 

well poo, not sure I am allowed to post files yet:( I'll put some things up on youtube.

 

Driving member 5.97 down

Driveshaft 2.88 down

Driven member 2.12 down

 

Operating angle 3.09 for Driving member to driveshaft (transfer case to driveshaft)

Operating angle .76 for driveshaft to Driven member (driveshaft to pinon)

= 2.33 degrees difference.

 

"Allowable range of difference between cancelling U-Joint working angles: 0.25 to 1.0 degrees." With a two degree shim, I will be within spec.

[ic3man5]

I ordered shims which should be delivered this week. My truck is going on it's third week now and they aren't any closer to identifying the vibe problem. I tolerate delays, but the slowness between the dealer and GM is maddening. They take some measurements and send them to GM a few days later, GM responds with next steps and so on. Minus the transmission making a whining noise, failed weld on one of the converters, the remaining issues are small. The Vibration and trans problems are enough to start talking to their toyota friends down the street who would be more than happy to sell me a Tacoma. The funny thing is i am the only person who has hope about the vibe going away. My wife wants the Silverado gone and replaced with something comfortable which is what I thought I bought, but 1500 miles later things changed for the worse.

 

I too think the clamps are adjusting the angle as well as preventing some resonance within the spring set.

 

I'll make a vid and post of the shims driving post install. I already have one as it is now. Spicer has an online angle calculator http://spicerparts.com/calculators/driveline-operating-angle-calculator that helps with specific numbers. I used my digital angle gauge and put them in the web site. The shim information is located in GM document number 4072382 PI1354B Feb 5, 2015 starting on page 8. I am attaching my numbers.

 

well poo, not sure I am allowed to post files yet:( I'll put some things up on youtube.

 

Driving member 5.97 down

Driveshaft 2.88 down

Driven member 2.12 down

 

Operating angle 3.09 for Driving member to driveshaft (transfer case to driveshaft)

Operating angle .76 for driveshaft to Driven member (driveshaft to pinon)

= 2.33 degrees difference.

 

"Allowable range of difference between cancelling U-Joint working angles: 0.25 to 1.0 degrees." With a two degree shim, I will be within spec.

 

I'm interested in doing this, any recommendations on an angle gauge?

[KLRV6]

 

I'm interested in doing this, any recommendations on an angle gauge?

I picked up a digital one off amazon. DXL360s http://amzn.com/B00IKDQHWO

 

There are several types available. I will post some of my findings if the dealership doesn't want to put the shims in. I sent them my reading and the service manager said he "eye balled it" and it looked ok. I wonder how accurate using the "eye ball" method is? Did he calibrate his eye before looking at it?

[hotrodz37]

I ordered shims which should be delivered this week. My truck is going on it's third week now and they aren't any closer to identifying the vibe problem. I tolerate delays, but the slowness between the dealer and GM is maddening. They take some measurements and send them to GM a few days later, GM responds with next steps and so on. Minus the transmission making a whining noise, failed weld on one of the converters, the remaining issues are small. The Vibration and trans problems are enough to start talking to their toyota friends down the street who would be more than happy to sell me a Tacoma. The funny thing is i am the only person who has hope about the vibe going away. My wife wants the Silverado gone and replaced with something comfortable which is what I thought I bought, but 1500 miles later things changed for the worse.

 

I too think the clamps are adjusting the angle as well as preventing some resonance within the spring set.

 

I'll make a vid and post of the shims driving post install. I already have one as it is now. Spicer has an online angle calculator http://spicerparts.com/calculators/driveline-operating-angle-calculator that helps with specific numbers. I used my digital angle gauge and put them in the web site. The shim information is located in GM document number 4072382 PI1354B Feb 5, 2015 starting on page 8. I am attaching my numbers.

 

well poo, not sure I am allowed to post files yet:( I'll put some things up on youtube.

 

Driving member 5.97 down

Driveshaft 2.88 down

Driven member 2.12 down

 

Operating angle 3.09 for Driving member to driveshaft (transfer case to driveshaft)

Operating angle .76 for driveshaft to Driven member (driveshaft to pinon)

= 2.33 degrees difference.

 

"Allowable range of difference between cancelling U-Joint working angles: 0.25 to 1.0 degrees." With a two degree shim, I will be within spec.

 

I have always read 2 degrees is the ideal operating angle, which you're not far off, but obviously the closer to 0 the better. Please keep us posted as I am going to order a set of shims today as well. Thanks for taking this on!

[LongrangeLauber]

 

I have always read 2 degrees is the ideal operating angle, which you're not far off, but obviously the closer to 0 the better. Please keep us posted as I am going to order a set of shims today as well. Thanks for taking this on!

Wouldn't you want it at a slight negative angle due to the pinion turning up when torque is applied? If it were -2 degrees then it would rotate to 0 degrees.

 

On my 02 I replaced the rear axle housing. Well the one I put in there was sort of rotted away due to the climate it was in (didn't notice until almost a year after replacement). The leaf spring pads rotted through the tube on the front so when torque was applied the pinion went real high and actually collided with the driveshaft. Had to replace the axle housing, get the gears reset in the new housing (had 4.88's in it) and also a new driveshaft cause it caused the u- joint strap bolts to mash into the driveshaft and damaged it pretty good.

 

Little off topic and I'm just rambling now, loved that truck, shouldn't have sold it lol

[KLRV6]

 

I have always read 2 degrees is the ideal operating angle, which you're not far off, but obviously the closer to 0 the better. Please keep us posted as I am going to order a set of shims today as well. Thanks for taking this on!

 

Pinion side shot posted. Looking at it, there is little pointing up which is where it needs to be.

 

 

[hotrodz37]

 

Pinion side shot posted. Looking at it, there is little pointing up which is where it needs to be.

 

 

Is this your truck KLRV6?

 

Are you saying the pinion angle is correct and yet you still have the vibe? Just trying to decipher this. Thanks!