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

[Doubeleive]

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

 

[PG01]

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

Yeah but, did YOU check them??

Lol

 

[Doubeleive]

I guess it doesn't help that I drive the thing like it's a corvette

 

[Doubeleive]

Yeah but, did YOU check them??

Lol

 

[PG01]

View attachment 228938

Not 40.... lol

 

[Rocket Man]

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]

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 .

 

[Rocket Man]

which upper ones are you using? those ones I see on there website all look round and have a divot in them mine are straight

My uppers are ACDelco Professional. I couldn’t find any better ones.

 

[Doubeleive]

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?

 

[Rocket Man]

looks like they don't sell a non adjustable one, I may go with the mevotech, any suggestions?

I don’t see much for the nnbs , weird. I guess just find the best one you can.