What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Doubeleive

Wes
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Hey I thought the same thing on my bagged Silverado when I got my new $6000 billet wheels that had a slightly different offset than what I ordered. I pushed and shook and had all kinds of room. Then I went for a drive and promptly scraped both lips on the fenders after going around a couple corners. Believe me, there’s no way you can simulate 4000 lbs ( or whatever our rigs weigh) of force being tossed sideways from g forces.

Edit: if you look at what keeps the suspension centered side to side you’ll see it can move. That’s where (anti) sway bars help but even the biggest can’t stop it completely.
ya, I was already looking for "heavy duty" rear control arms and maybe the panhard bar earlier, not sure how much help those would be though
 

Doubeleive

Wes
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anybody ever use these or something like them
https://www.ebay.com/itm/Boxed-Rear...r:2012&hash=item27e53d899c:g:uZwAAOxyrx5Tj2u6

spohn.JPG
 
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I run something similar on my mustang. They flex less because they're boxed (stock ones are open along the bottom), and have tougher/harder poly bushings. Because of the stiffer bushings there is a bit more road noise transferred into the cabin, but loud exhaust or stereo easily covers it.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
 

Rocket Man

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Bigkevschopshop

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Rebuilt my drivers side blend door actuator. Caked with grease everywhere it shouldn’t. I swear a 5 year old greased this. Grease all over circuit board and copper contacts. Moved grease to gear faces and lubricated the shafts they ride on then cleaned the grease off circuitry and position contacts. Cleaned it up and so far it’s colder. 45 minute job. Even with console in place and 20 minuets cleaning and lubing actuator.
 

iamdub

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I just drive hard is all, hence the hellwig sway bars and anything else I can upgrade to heavy duty

The panhard is what locates the rear. The control arms do virtually nothing for sideways (lateral) support. I looked at mine earlier and saw the same rub marks on the plastic. They're not quite as bad as yours, but my Tahoe's not quite as heavy as your XL and I may not huck it quite as hard as you do yours. I have the same tires with what looks to be the same amount of wear. I noticed what may have been some slight rubbing marks on the control arms, too.

The rear isn't exactly centered and it does shift sideways slightly as it travels up and down since the panhard swings in an arc. Here's a little video that shows it in action on a drawing:

The pivot points are opposite of how they are on our trucks (ours has the frame mount on the RH side), but it's all the same. You can see how the rear moves laterally just a hair. The axle moving inward, plus the body leaning, plus the tire sidewall rolling inward all lead to the tire contacting the inboard areas. Beefing up the control arms wouldn't do much at all for this. Beefing up the panhard is about all that could make the only real difference.
 

Doubeleive

Wes
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The panhard is what locates the rear. The control arms do virtually nothing for sideways (lateral) support. I looked at mine earlier and saw the same rub marks on the plastic. They're not quite as bad as yours, but my Tahoe's not quite as heavy as your XL and I may not huck it quite as hard as you do yours. I have the same tires with what looks to be the same amount of wear. I noticed what may have been some slight rubbing marks on the control arms, too.

The rear isn't exactly centered and it does shift sideways slightly as it travels up and down since the panhard swings in an arc. Here's a little video that shows it in action on a drawing:

The pivot points are opposite of how they are on our trucks (ours has the frame mount on the RH side), but it's all the same. You can see how the rear moves laterally just a hair. The axle moving inward, plus the body leaning, plus the tire sidewall rolling inward all lead to the tire contacting the inboard areas. Beefing up the control arms wouldn't do much at all for this. Beefing up the panhard is about all that could make the only real difference.
ya I kinda figured that the panhard was the more critical part here, I was trying to look around at other ones besides just the spohn, I figure I can get that and adjust it to the same length as the stock one set it and forget it, maybe the poly bushings will be more snug than the stock rubber bushings, my thought is to replace the upper & lower control arms and the panhard bar all in one shot.
 

Doubeleive

Wes
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Doubie, hows your air pressure on the tires? Maybe they dropped enough to bulge and just rub a bit, plus running hard around turns? Just a thought
I generally run them about 40 psi, just had a mobile 1 service done couple days ago at the dealer with rotation and asked them to make sure they were set to 40
 

Rocket Man

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The panhard is what locates the rear. The control arms do virtually nothing for sideways (lateral) support. I looked at mine earlier and saw the same rub marks on the plastic. They're not quite as bad as yours, but my Tahoe's not quite as heavy as your XL and I may not huck it quite as hard as you do yours. I have the same tires with what looks to be the same amount of wear. I noticed what may have been some slight rubbing marks on the control arms, too.

The rear isn't exactly centered and it does shift sideways slightly as it travels up and down since the panhard swings in an arc. Here's a little video that shows it in action on a drawing:

The pivot points are opposite of how they are on our trucks (ours has the frame mount on the RH side), but it's all the same. You can see how the rear moves laterally just a hair. The axle moving inward, plus the body leaning, plus the tire sidewall rolling inward all lead to the tire contacting the inboard areas. Beefing up the control arms wouldn't do much at all for this. Beefing up the panhard is about all that could make the only real difference.
And sway bar and sway bar end links. The beefed up control arms keep the axle from twisting under high hp applications, that’s why I use the Spohn ones. As far as panhard, I run the QA1 which has a bend that curves around the diff, allowing me to run a girdle on my G80 to keep it together, and it’s beefier than the adjustable or stock ones. So it all depends on how hard you drive, what kind of HP you’re running and how low or high you are as to what components you need to decide on. We also need to keep in mind everything works together so if there’s a weak point it might affect the other components even if they’re not directly related, like if I get axle twist as I’m punching it going around a corner it will affect the suspension by changing the angle of the panhard bar and the end links. At least in my mind it does lol. Which affects the truck....
 

Rocket Man

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ya I kinda figured that the panhard was the more critical part here, I was trying to look around at other ones besides just the spohn, I figure I can get that and adjust it to the same length as the stock one set it and forget it, maybe the poly bushings will be more snug than the stock rubber bushings, my thought is to replace the upper & lower control arms and the panhard bar all in one shot.
If you want stiffer, don’t get an adjustable. I’ve seen the Spohn adjustable control arms ripped apart by superchargers because although it’s cool that you can adjust the forward/ rear position of the axle for lowered/ lifted applications, they’re weaker. Get a QA1 or Spohn non-adjustable .
 

Doubeleive

Wes
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If you want stiffer, don’t get an adjustable. I’ve seen the Spohn adjustable control arms ripped apart by superchargers because although it’s cool that you can adjust the forward/ rear position of the axle for lowered/ lifted applications, they’re weaker. Get a QA1 or Spohn non-adjustable .
looks like they don't sell a non adjustable one, I may go with the mevotech, any suggestions?
 

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