Any & all help/suggestions welcome

[Jeremy4601]

So, I have been working through a few “ride” issues with my Tahoe for some time now. I am down to just a couple things that I can’t seem to satisfy on my own. My two remaining problems as of now are:

1. While driving I am noticing a “scrubbing” noise from the truck. It sounds like a sanding block being worked back and forth. I can only hear it when my window is down and I pass alongside other vehicles or fence lines allowing the sound to be redirected back at me. I assume it’s something to do with either axle on the drivers side, but I have been thru both and not noticed anything jumping out at me. That isn’t saying much tho as my mechanical knowledge is... well, let’s just call it “limited”.

2. Much to my dismay and despite my best efforts, my rig tends to “float” down the road. The steering is tight, it takes bumps pretty well, and I have done quite a bit of work to correct this (list of such is coming up next). I have made significant progress, however I still find myself working harder than I should have to to keep this thing between the lines.

In the past few months I have replaced brake pads, rotors, and calipers all the way around. I replaced the steering gearbox, pitman arm, and idler arm. I had the front end aligned. Also have had two different shops go thru the front end and have been given a clean bill of health from both.

I also replaced all four struts. Not knowing much about these, I went to O’Reilly’s and bought what they said would fit. I tried to look back to be able to say exactly what I put on there but I was not able to find that info. I definitely did not spend more than $50 on each, so I may have gotten exactly what I paid for. The struts I took off looked about the same size as what I was putting back on so I had no reason to question anything. They also appeared to be OE as they definitely looked like they had been on there for a long long time.

I am running aftermarket wheels. Ballistic 20’s along with 275/55/20 tires.

Sorry for the long-winded post, but I’m struggling to sort this out on my own... so I wanted to be thorough with my info. I’ve just turned 240k on the odometer, so I certainly don’t expect her to ride like a brand new truck. But it’s gotta be able to get better than it is. Any thoughts, experiences, or suggestions would be greatly appreciated.

 

[Jeremy4601]

I actually sat and created a signature before making the above post and it apparently didn’t attach. So my rig info is : 2002 Tahoe, 4WD, 5.3, 4L60e, LS Positraction rear end

 

[Fless]

I assume that the sway bar links and bushings have been replaced and are tight.

Your Hoe shipped with the "Premium Smooth Ride" suspension (RPO code ZW7). The rear shocks are self-leveling using Nivomat technology and, for the smooth ride the rear springs are softer than Z71 springs. (EDIT: the parts catalogs sometimes call this Self Leveling Suspension and may not mention the ZW7 RPO code.)

Although you said you replaced the struts, I think you mean the shocks. If you have the O'Reilly part numbers, tell us what they are.

The rear shocks should be pretty huge in comparison to a regular shock if they're still the Nivomats, but would have cost a lot more than the $50 you quoted. If the rear springs are original and the shocks are NOT Nivomats, then your truck will not ride correctly. The shocks and springs are a technology "set" and are designed to be used together.


For the scrubbing noise, does it happen when moving forward, reverse, and standing still? Or just one or two of those?

 

[Jeremy4601]

I assume that the sway bar links and bushings have been replaced and are tight.

Your Hoe shipped with the "Premium Smooth Ride" suspension (RPO code ZW7). The rear shocks are self-leveling using Nivomat technology and, for the smooth ride the rear springs are softer than Z71 springs. (EDIT: the parts catalogs sometimes call this Self Leveling Suspension and may not mention the ZW7 RPO code.)

Although you said you replaced the struts, I think you mean the shocks. If you have the O'Reilly part numbers, tell us what they are.

The rear shocks should be pretty huge in comparison to a regular shock if they're still the Nivomats, but would have cost a lot more than the $50 you quoted. If the rear springs are original and the shocks are NOT Nivomats, then your truck will not ride correctly. The shocks and springs are a technology "set" and are designed to be used together.


For the scrubbing noise, does it happen when moving forward, reverse, and standing still? Or just one or two of those?

Sway bar links and bushings have NOT been replaced as long as I have had the truck.

As far as the shocks go, I’m not able to get the part numbers. I tried, but they can’t seem to find the transaction for me. Also, the springs were not replaced. Based on your comment, it seems I may have messed myself up a bit by replacing the shock with something incompatible with that existing spring.

Any recommendations on a shock/spring replacement for my truck? I’m happy to spend what is necessary for a good ride, but I don’t need to break the bank. My truck rarely even sees a dirt road and I don’t pull anything over a small utility trailer, so I have no use for any high-end gear.

Regarding the scrubbing noise, I only notice it when driving forward, at pretty much any speed. As I said, I can only hear it when I’m close to other traffic or fence lines / shrub lines where the sound can bounce back at me. When I’m driving with nothing there to bounce it back at me I can’t hear it at all.

 

[Fless]

To be clear, one can convert from the Nivomat system on the rears if a combo like Rock Auto shows is used. Springs must be replaced with firmer ones at the same time as the shocks in order to maintain stability.



You can go either way, though. Get the Nivomat shocks or replace the springs and keep your shocks. Just so the technology is matched. Can't go wrong with Bilstein, but there are other choices. You could get the Z71 springs from a junkyard or UPull.

 

[Fless]

For the scrubbing noise, check the rear axle backing plates behind the e-brake shoes. Those are usually rusted out or deformed and the rotor may be scraping on it.

Others may have some good suggestions.

 

[GreyStone]

have you tried increasing the air pressure in your tires - what load range are they?

 

[Jeremy4601]

To be clear, one can convert from the Nivomat system on the rears if a combo like Rock Auto shows is used. Springs must be replaced with firmer ones at the same time as the shocks in order to maintain stability.


View attachment 251796

You can go either way, though. Get the Nivomat shocks or replace the springs and keep your shocks. Just so the technology is matched. Can't go wrong with Bilstein, but there are other choices. You could get the Z71 springs from a junkyard or UPull.

It seems I may have really stepped in it when I changed those shocks. Not knowing any better, I trashed the OE shocks. I guess I was just throwing mud at the wall and hoping some of it would stick. Just look at me now! Lol

Those Nivomat shocks look to be $300-$400 a piece.

I found a Bilstein kit for $285 that has the 4600 shocks and the 9021 springs. This seems like a better solution to me.

Any potential pitfalls regarding my replacement of the front shocks? Other than the fact that I opted for the low-end option? I may go ahead and order another set of the 4600’s for the front. Would these require the spring replacements as well?

And thanks also for the info about that scrubbing noise. I’m definitely going to check that out next chance I get.

Would the swaybar links and bushings be something I should be concerned about even tho two different places have looked at the front end and said it was good?
BBC

 

[Luie]

Wheel bearings?

 

[Fless]

The front suspension is torsion bar style, so no coil springs, and likely that's not been changed unless the keys have been cranked (front end "leveled"). Your jounce stops -- the front ones are not "bump" stops -- play an integral role in the handling and act as a fulcrum point of the suspension. They should be in good shape and, at ride height, be contacting the lower control arm right near the shock. This shows you where they are:

Absolutely check all of the front swaybar links/connections for tightness, and make sure the bushings are in good shape. They're not expensive and do end up deteriorating over the miles and years.

After checking the easy stuff on the front end, I'd probably concentrate on the rear suspension first, since replacing the OE shocks with standard ones is known to make the handling bad. I think that the front OE shocks for the Premium Smooth Ride are smaller Nivomats but I could be wrong. I think just a good heavy duty shock up there would work fine, and yours might be okay after the rear end work. Maybe someone with more experience on the fronts could chime in.