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Discussion Starter · #1 ·
2500 hd. I just switched stock tires for Ko2 (stock size on 18” wheels). I drove some light to moderate off-road trails yesterday and today. In the rockier sections, I noticed a “clunk” feel as the wheel moved back and forth. The steering seemed a bit looser after the clunk developed. It seems like something loosened in the steering column or connectors? Anyway, back on pavement it drives straight with no vibration but it doesn’t seem as smooth and the steering seems loose. Anyone have any suggestions as to what might be wrong?

thanks in advance!
1079077
 

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It's one of two issues: a bad upper ishaft or hydraulic hammer in power steering cooler. To check the ishaft, put the truck is accessory mode so the steering wheel is locked. Turn the wheel back and forth and listen for any clunking. If it does not clunk, it is likely hydraulic hammer. Hydraulic hammer sounds like something is rattling in column but it is a hydraulic resonance in power steering system.
 

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Discussion Starter · #4 ·
It's one of two issues: a bad upper ishaft or hydraulic hammer in power steering cooler. To check the ishaft, put the truck is accessory mode so the steering wheel is locked. Turn the wheel back and forth and listen for any clunking. If it does not clunk, it is likely hydraulic hammer. Hydraulic hammer sounds like something is rattling in column but it is a hydraulic resonance in power steering system.
You nailed it...it was a bad ishaft!
 

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Discussion Starter · #6 ·
No bulletin that I know of. I am waiting for dealer to get the replacement and it will be replaced under warranty. Hope it was just a defective part rather than something more pervasive.
 

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2020 Silverado 4WD LTZ Duramax Crew Cab
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I have a 2020 Silverado 2500 LTZ and my truck is in the dealer shop for the 4th time for the same issue, they keep saying there is nothing wrong. When driving once everything gets warmed up I feel every crack in the road through the steering wheel, when taking a corner there is almost a clunking I feel, when hitting bumps in the road at 65mph the steering will shake back and forth until the road smooths out. I spoke to the tech today he said everything checks out OK, all the front suspension and steering components. My truck only has 7700 miles on it. Anyone have a suggestion?
 

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I have a 2020 Silverado 2500 LTZ and my truck is in the dealer shop for the 4th time for the same issue, they keep saying there is nothing wrong. When driving once everything gets warmed up I feel every crack in the road through the steering wheel, when taking a corner there is almost a clunking I feel, when hitting bumps in the road at 65mph the steering will shake back and forth until the road smooths out. I spoke to the tech today he said everything checks out OK, all the front suspension and steering components. My truck only has 7700 miles on it. Anyone have a suggestion?
Make sure to check the sway bar end links to ensure they are tight (squish those rubber bushings to where they bulge out).

I previously had a very annoying rattle which I could feel through the steering wheel, and that ended up being the culprit.

Also remember that GM‘s idler arm design on the steering linkage is drastically undersized for the larger and higher grip tires put on today’s larger trucks.

It truly irritates me that I have to replace most of the steering linkage on a brand new truck just to increase the tire size because the manufacturer’s are too cheap to upsize the steering components for today’s bigger trucks.

I put on heavy duty tie rods, heavy duty pitman & idler arms, bigger sway bars w/ better end links, etc ... and I have had not one issue in 18 months and 20,000 miles since upgrading these components ... and my steering is more solid and tighter than the day I purchased it new off the lot.

Thankfully there are good aftermarket companies who offer heavy duty components to replace those weak factory components ...
 

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@2149USMC If you truck was built before November, there is a steering calibration update if your truck is a higher trim with digital assist steering.

#iworkforGM
 

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2020 Silverado 4WD LTZ Duramax Crew Cab
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Make sure to check the sway bar end links to ensure they are tight (squish those rubber bushings to where they bulge out).

I previously had a very annoying rattle which I could feel through the steering wheel, and that ended up being the culprit.

Also remember that GM‘s idler arm design on the steering linkage is drastically undersized for the larger and higher grip tires put on today’s larger trucks.

It truly irritates me that I have to replace most of the steering linkage on a brand new truck just to increase the tire size because the manufacturer’s are too cheap to upsize the steering components for today’s bigger trucks.

I put on heavy duty tie rods, heavy duty pitman & idler arms, bigger sway bars w/ better end links, etc ... and I have had not one issue in 18 months and 20,000 miles since upgrading these components ... and my steering is more solid and tighter than the day I purchased it new off the lot.

Thankfully there are good aftermarket companies who offer heavy duty components to replace those weak factory components ...
I just went and looked at the sway bar links, the ones on my truck are a new design they are a side mount not an end to end mount. But I did notice something, the LCA bump stops are not even a 1/4" off of the LCA, which to me means that on a bumpy road the LCA is pounding the bump stops. Do you know what the specs are on these?
2020 Silverado 2500HD LTZ duramax.
 

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I just went and looked at the sway bar links, the ones on my truck are a new design they are a side mount not an end to end mount. But I did notice something, the LCA bump stops are not even a 1/4" off of the LCA, which to me means that on a bumpy road the LCA is pounding the bump stops. Do you know what the specs are on these?
2020 Silverado 2500HD LTZ duramax.
GM IFS trucks have been that way forever. Not a big deal and there is no specific factory “spec” for that specific measurement.
 

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I've seen a few bad I-shafts on the new bodies.. The slip splines are loose.. I know that they are wanting the failed ones back to look into it.. Who knows what they will do about it.
 

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I have a 2020 Silverado 2500 LTZ and my truck is in the dealer shop for the 4th time for the same issue, they keep saying there is nothing wrong. When driving once everything gets warmed up I feel every crack in the road through the steering wheel, when taking a corner there is almost a clunking I feel, when hitting bumps in the road at 65mph the steering will shake back and forth until the road smooths out. I spoke to the tech today he said everything checks out OK, all the front suspension and steering components. My truck only has 7700 miles on it. Anyone have a suggestion?
What size wheels and tires? Worn I-shaft shouldn’t cause a shake in the steering wheel over bumps. Has the dealer attempted any repairs at all? If it’s been in 4 times now, they are truly missing the point if they haven’t tried to do anything for you at all. Even if that means showing you that your truck is “the same” by taking you for a drive in an identical truck.
 

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Make sure to check the sway bar end links to ensure they are tight (squish those rubber bushings to where they bulge out).

I previously had a very annoying rattle which I could feel through the steering wheel, and that ended up being the culprit.

Also remember that GM‘s idler arm design on the steering linkage is drastically undersized for the larger and higher grip tires put on today’s larger trucks.

It truly irritates me that I have to replace most of the steering linkage on a brand new truck just to increase the tire size because the manufacturer’s are too cheap to upsize the steering components for today’s bigger trucks.

I put on heavy duty tie rods, heavy duty pitman & idler arms, bigger sway bars w/ better end links, etc ... and I have had not one issue in 18 months and 20,000 miles since upgrading these components ... and my steering is more solid and tighter than the day I purchased it new off the lot.

Thankfully there are good aftermarket companies who offer heavy duty components to replace those weak factory components ...
Yes. Shame on the manufacture for not making a truck that can handle larger than factory tires. T1’s can be optioned with a 34” tire from the factory. I don’t believe the steering or suspension components lack structural integrity for a stock or even mildly modified set up since 2011, personally.
 

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I just went and looked at the sway bar links, the ones on my truck are a new design they are a side mount not an end to end mount. But I did notice something, the LCA bump stops are not even a 1/4" off of the LCA, which to me means that on a bumpy road the LCA is pounding the bump stops. Do you know what the specs are on these?
2020 Silverado 2500HD LTZ duramax.
Those are actually called jounce bumpers ... not to be confused with the old bump stops.

They are part of the suspension system providing a progressive resistance as the control arm movement “squishes” them.

Once they “squish” to a certain point they will then act as a bump stop.

The spec is to adjust the torsion bars to where the jounce bumpers are just touching the stops.

Hopefully that answers your question.
 

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2020 Silverado 4WD LTZ Duramax Crew Cab
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Those are actually called jounce bumpers ... not to be confused with the old bump stops.

They are part of the suspension system providing a progressive resistance as the control arm movement “squishes” them.

Once they “squish” to a certain point they will then act as a bump stop.

The spec is to adjust the torsion bars to where the jounce bumpers are just touching the stops.

Hopefully that answers your question.
I picked my truck again from the dealership yestardy, they finally identified the issue. They road force balanced all foour tires and three of them are bad. I have asked the dealership to replace all four and not with the OEM goodyear trailrunners. From my research on these tires they are a good riding tire as a 8ply or less but not a 10ply. Waht are your thoughts?
 

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Yes. Shame on the manufacture for not making a truck that can handle larger than factory tires. T1’s can be optioned with a 34” tire from the factory. I don’t believe the steering or suspension components lack structural integrity for a stock or even mildly modified set up since 2011, personally.
Broke the passenger side factory tie rod (inner) backing out of my driveway within a few days of installing a Tuff Country leveling kit and 35 inch tires (285/75R18).

Since the Tuff Country leveling kit did not include aftermarket knuckles to return the tie rods to factory angles, I likely incorrectly blamed it on the leveling kit.

So I removed the Tuff Country leveling kit, replaced both factory tie rods with Moog’s (Federal Mogul) “problem solver” tie rods, and installed a high quality Fabtech leveling kit with aftermarket knuckles that corrected the tie rods angles back to factory ... and this high quality leveling kit also corrected upper and lower ball joint angles, and some of the cv joint angle ... which almost no other leveling kit does all this.

Then a week later I broke the idler arm inside the main housing that mounts to the frame.

Hmmm ? ... started to think it was not the leveling kits, so I replaced the factory idler arm with a Moog “problem solver and thought I would give this ongoing problem one more chance before I made some drastic changes.

Within a few weeks I broke the passenger side Moog tie rod ... and this point I was f-cking pissed ! 😡

So I ordered a high quality FabTech 4 inch differential drop lift kit, Fabtech heavy duty tie rods, Kryptonite heavy duty pitman & idler arms, and a Cognito PISK (which I later took off because it was not needed and it was in the way for my BDS steering stabilizer).

That was over a year and 25,000 miles ago. Not one problem since and my steering is tighter than the day I bought the truck new off the lot.

So you can’t blame it on the leveling kit(s x 2).

Why is it that the heavy duty aftermarket parts have stood up to worse abuse over a much longer time period with the same larger tires and the same knuckle design Fabtech puts on their leveling and lift kits ?

Oh ... and I forgot to mention that Fabtech tech support told me they use most of the GM knuckle design to make the casting mold for their knuckles. They literally cut off a few connection points to recast so they can machine their connections. So you can’t even blame it on steering component geometry because it is GM, knuckle design / angles / measurements.
 

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Broke the passenger side factory tie rod (inner) backing out of my driveway within a few days of installing a Tuff Country leveling kit and 35 inch tires (285/75R18).

Since the Tuff Country leveling kit did not include aftermarket knuckles to return the tie rods to factory angles, I likely incorrectly blamed it on the leveling kit.

So I removed the Tuff Country leveling kit, replaced both factory tie rods with Moog’s (Federal Mogul) “problem solver” tie rods, and installed a high quality Fabtech leveling kit with aftermarket knuckles that corrected the tie rods angles back to factory ... and this high quality leveling kit also corrected upper and lower ball joint angles, and some of the cv joint angle ... which almost no other leveling kit does all this.

Then a week later I broke the idler arm inside the main housing that mounts to the frame.

Hmmm ? ... started to think it was not the leveling kits, so I replaced the factory idler arm with a Moog “problem solver and thought I would give this ongoing problem one more chance before I made some drastic changes.

Within a few weeks I broke the passenger side Moog tie rod ... and this point I was f-cking pissed ! 😡

So I ordered a high quality FabTech 4 inch differential drop lift kit, Fabtech heavy duty tie rods, Kryptonite heavy duty pitman & idler arms, and a Cognito PISK (which I later took off because it was not needed and it was in the way for my BDS steering stabilizer).

That was over a year and 25,000 miles ago. Not one problem since and my steering is tighter than the day I bought the truck new off the lot.

So you can’t blame it on the leveling kit(s x 2).

Why is it that the heavy duty aftermarket parts have stood up to worse abuse over a much longer time period with the same larger tires and the same knuckle design Fabtech puts on their leveling and lift kits ?

Oh ... and I forgot to mention that Fabtech tech support told me they use most of the GM knuckle design to make the casting mold for their knuckles. They literally cut off a few connection points to recast so they can machine their connections. So you can’t even blame it on steering component geometry because it is GM, knuckle design / angles / measurements.
Well, I have certainly not seen it all and I’ll be one of the first people to say that nothing is perfect. However, I’ve spent 24 years wrenching on GM vehicles and a good portion of that specifically doing just steering, suspension and brake work at a large Chevy dealer in rural Michigan. I’ve never seen a tie rod end or idler arm break under the same conditions that yours did. That’s all I’m going to try to say. I’ve actually seen stock components last through more things than I would have ever put their through or thought they would last through. The 2001-2010 HD GM truck chassis set was certainly not as robust as it should have been, no doubt. Since then, GM has really stepped up their game. Again, nothing is perfect but my years of experience is certainly the opposite way of what your truck has done to you.
 
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