Steering Rack Noise (w/Video)

[Chris_Lum]

Update: Fixed as of 3/31/22 (Steering Knock Bushing fixed the high speed steering wheel shaking)

Background: I've been trying to track down a steering wheel vibration at high speed. I know it's usually caused by wheel imbalance, but I thought I'd get your opinions on the rack first.

Car: 1991 w/126K miles w/Manual Rack

Symptoms: *Intermittent* Steering Wheel vibration at moderate to high speed (50+ mph)

Relevant info:

-Wheel Bearings - Original (seem good, smooth and no abnormal noise)
-Upper & Lower front control arms - Original (bushings are old, minor cracking, but are not severely worn or deteriorated)
-Steering Rack - original
-Steering rack bushings - (I see some cracking, but I don't see any movement of the rack itself during the video, so it seems the sound is inside the rack itself)
-New OEM inner and outer tie rods installed
-New Carbon6 ball joints installed (upper and lower on both front knuckles)
-New KW V3 suspension installed
-Everything torqued appropriately, steering U joint, inner/outer tie rods, wheel hubs
-Brake rotors and pads are brand new stoptech rotors w/hawk HPS pads
-TE37 w/6 yr old Falken RT615K (TE are not bent as they are in mint condition, but I have no idea how old tires can behave--old in age but 70% tread life left)

Questions:

1) Would you say the noise in the video requires a rack rebuild?
2) Do you think the rack condition is causing the steering wheel vibration?

My Plan: If the opinion is that the vibration is NOT being caused by the steering rack then I will move on to the wheels:
-Rebalance Wheels
-Try hub centric rings
-Get new tires


My final thoughts: the part that confuses me the most is that the steering wheel vibration is intermittent. This is my first manual steering rack car and I thought maybe I'm not used to how the steering wheel relays every bump in the road. However, I came to the conclusion that the vibration/shaking is not normal since it goes away sometimes and steering is perfectly steady. I thought maybe it has to do with the road, but I've driven on completely smooth tarmac highways and it still vibrates at times. I'm mainly looking for your expertise opinions to lead me one way or the other. Obviously a new rack is the most expensive choice, but if it will fix the steering wheel shaking, then I will gladly do it. If you all think it's most likely the wheels/tires, then I will move up my timeline for new tires (I know 6 yr old tires are not ideal, but I kept them for now since they have a lot of tread life left and I'm just driving around town, nothing spirited).

 

[Creasian21]

i had vibrations at 50+ mph, try road force balance.

 

[dablackgoku1234]

I have been tracking down similar symptoms on my car, but with much more miles (150k+ miles)

My observations: intermittent vibration. It comes and goes especially when going around a bend on the highway.

I’ve done the following so far without success of eliminating the problem:

1) new wheels
2) new tires
3) road force balanced new wheels and tires
4) hub centric rings
5) newish steering rack bushings from SOS (10 years ago)

Things still needed to be done:

1) add steering rack bushing (from Les in Australia)
2) change wheel hub/bearing

 

[Chris_Lum]

Thanks for your responses. I just realized I mistyped my milage. I have 126k, not 12k lol

I'm currently waiting for my new tires to come in next month, which I hope will fix the problem...however I'm not certain it will. I had set of BBS LM with new front tires on them that I took off and I remember having the shaking back then as well (at that time, I thought it was bad rotors though because I had vibrations on braking as well--this was before I installed brand new pads and rotors and why I'm able to rule them out right now).

I posted this issue up on the prime FB page and Charles Brown from the NSX rack repair company said in regards to the steering rack being the cause of the shaking: "shaking the wheel is not common unless the car has been in an accident." which I don't think mine has (as far as I can tell). I just hope it's wheel/tire or wheel bearing related since those are all fairly easy to remedy.

I do have the common passenger side clunk on bumps, which I know the steering rack bushing from Les will fix, but as far as I have learned, it will just fix that up/down clunk noise, not any left/right play or shaking in the steering.

My greatest fear is if something "invisible" is causing the shaking, like an old/worn chassis. I was chasing this issue on a past 00 Integra I had with 350K miles on the chassis and the chassis itself was the problem. I changed out every single possible part it could be (wheel bearings, brakes, knuckles, steering rack, engine mounts, wheels, tires, suspension, etc.) Once I swapped all my parts to a new low mileage chassis, the shaking went away.

 

[dablackgoku1234]

Just watched the video, the “knock bush” will eliminate that noise. I had a local company rebuild my steering rack and the noise came back after a year or so. So I hope Les’s bushing will be a more permanent fix.

I *don’t think* it is related to the vibration, but I’m grasping at straws in my situation. I’ve had this intermittent vibration for the longest time and just trying everything in short of replacing the whole front suspension. I’m in favour of trying solutions in increasing cost. I was at the point of new wheels and tires road force balanced and still didn’t solve the issue. Perhaps it may be different for you. My next trial and error will be bushing and wheel bearing.

 

[NSX-SA]

Hi Chris, sorry I'm late to this thread.

Shaking of the steering wheel at speed is not common in the NSX however can be attributed to wheel balancing or old tyres.

Depending on the age and condition of your front tyres i would change them first, second as mentioned previously fit a rack end knock bush to remove the slow speed knock.

If you don't want to change your front tyres see if you can borrow a set from another NSX.

From your video if you have play in the wheel the rack and pinion may need to be adjusted this again is uncommon your rack may need a full rebuild.

 

[Chris_Lum]

Hi Chris, sorry I'm late to this thread.

Shaking of the steering wheel at speed is not common in the NSX however can be attributed to wheel balancing or old tyres.

Depending on the age and condition of your front tyres i would change them first, second as mentioned previously fit a rack end knock bush to remove the slow speed knock.

If you don't want to change your front tyres see if you can borrow a set from another NSX.

From your video if you have play in the wheel the rack and pinion may need to be adjusted this again is uncommon your rack may need a full rebuild.

Thanks for your response!

Coincidentally, the steering shake was fixed this week. I finally got my new tires after a couple months wait time and it solved the steering shake.

Interestingly though, I've discovered that the steering shake symptoms I was experiencing was partly due to the tires but also partly due to road surface or inherent to the car (manual steering or otherwise). What do I mean by that? The city recently repaved SB Interstate 5 next to my house and did not yet pave the NB side so I was able to have a control environment. I noticed that there is still some slight steering movement on the NB side, but on the newly paved SB side, the steering is rock solid. I would say my previous steering shake problems were probably 75% the 6 yr old tires and 25% road surface feedback (and my unfamiliarity with how sensitive or how much normal feedback a manual steering rack gives).

Anyhow, I'm glad this has been fixed with relatively little hassle. Thanks for the help everyone!

 

[MexiRicer]

Glad to see you sorted your issue Chris! Those falken 615 get very hard after only a few years! Your new rt660 look like a great improvement so far.

 

[Old Guy]

A bit late to the party and it already looks like you have fast tracked to my suggestion. In your initial post you mentioned that the vibration was intermittent and I was going to post that the vibration may be a combination of the road surface, the particular tire and temperature. Around here, some years ago the Dept. of Highways experimented with something called popcorn asphalt mix. I think it was designed to shed water faster. In my NSX it is immediately obvious when you encounter a patch of this stuff because the road / tire nose increases to a dull roar (drowns out the wind noise from the door glass). Under the right conditions it can set up a noticeable vibration in the steering wheel. The vibration seems to vary with temperature which may be affecting the compliance of the tire sidewalls and possibly the damping in the suspension.

 

[Chris_Lum]

Glad to see you sorted your issue Chris! Those falken 615 get very hard after only a few years! Your new rt660 look like a great improvement so far.

thanks Robert!

A bit late to the party and it already looks like you have fast tracked to my suggestion. In your initial post you mentioned that the vibration was intermittent and I was going to post that the vibration may be a combination of the road surface, the particular tire and temperature. Around here, some years ago the Dept. of Highways experimented with something called popcorn asphalt mix. I think it was designed to shed water faster. In my NSX it is immediately obvious when you encounter a patch of this stuff because the road / tire nose increases to a dull roar (drowns out the wind noise from the door glass). Under the right conditions it can set up a noticeable vibration in the steering wheel. The vibration seems to vary with temperature which may be affecting the compliance of the tire sidewalls and possibly the damping in the suspension.

yeah after driving around with the new tires more, I would have to adjust my assessment and flip flop the percentages. I'd say my shaking was 75% due to road surface conditions and 25% due to tires. It really helps that I have a "control" surface now due to the freshly paved highway. Previously I couldn't tell why my steering wheel would vibrate on certain roads and not others. But because my steering wheel is dead solid on the newly paved highway, I'm able to confidently say that my car doesn't have anything wrong with it causing the steering shake. On the other hand, that just means I need to get used to the "natural" steering shake/vibration I get on not-so-nice road surfaces.

 

[Chris_Lum]

Update: 9/19/21

Finally fixed the high speed steering shake for real this time. Turns out it was the brake calipers. I cleaned and lubed the caliper guide pins and also the pad mounting clips/anti-rattle clips and the shaking went away. Drove it around the usual spots for the past week and confirmed the shaking at 60+ mph has disappeared. The solid steering was actually noticeable even as low as 20mph.

Background: I've only had this car since Dec 2020 and put 2K miles on it so far. The car had steering shake on braking when I first bought it. It sat on jack stands for a few months, then I eventually changed the front rotors to barely used OEM rotors from a friend paired with new stoptech sport pads. Shaky steering on braking came back around 500 miles later so I figured the used rotors must need to be resurfaced (I didn't resurface them originally because they looked barely used with no "lip" on them). Instead of resurfacing them, I purchased a new set of stoptech slotted rotors and PMU pads. Fast forward 1500 miles and I noticed the return of my steering pulsating/shaking on braking. At this point I knew something had to be up with the braking system because that's way too early for rotors and pads to start developing these types of issues with the way I was driving the car (no spirited driving or any way to embed pad material unevenly on the rotor--just driving around town so far). I removed the guide pins, which *surprise* were somewhat dry, to clean and lube them. Took the pad clips out and cleaned them with a wire brush Dremel bit.

What a difference this bit of maintenance has made. As I mentioned above, I even noticed a smoother steering wheel while driving around at slow speed 10-20mph. I didn't even realize my steering wasn't perfectly smooth at low speed before. I've driven probably 100 miles since, on all road surfaces and the steering is as smooth as can be. I ONLY feel the road imperfections, which I can finally tell the difference of now. (I previously mentioned how this was my first manual steering rack car so I wasn't sure how much road feeling I was supposed to be having). I can see now how the steering shake I had at high speed was definitely attributed to a rotational issue on the car being that it was cyclical (for lack of a better word) vs. simply feeling the road imperfections, which are not cyclical whatsoever.

In retrospect, I'm guessing this is why my steering shake felt intermittent. Since the calipers slide back and forth and, in my case, may have NOT sliding smoothly, the caliper must have affected the steering based on what position the caliper was stuck in--which would vary since I use the brakes at many different points while driving.

 

[Chris_Lum]

Update 3/31/2022

Short Answer: Fixed the steering shake FOR REAL REAL. Turns out the steering rack knock bushing fixed my shaking.

Long Answer: I thought it was the brake calipers as of 9/19/21 but the shaking came back. After that, I ended up rebuilding the calipers (didn't fix it) then I purchased Spoon Calipers (didn't fix it). Then I replaced the front wheel bearings and installed Prothane bushings on the front uprights (didn't fix it). Another NSX member sent me a DM on IG saying that he had the same problem and installed the knock bushing and it made a world of difference, so I had to try it. I hit up Les from Australia to purchase his knock bushing and it was a night and day difference. 100% of shaking is gone and I've driven the car a few hundred miles. I'm confident it's finally fixed now. I ended up making a ton of DIY videos for my YouTube channel on everything I tried along the way, so I'll just drop them here in case others go down the same path I did.

 

[dablackgoku1234]

Chris, your videos made me go all out this winter. I’ve replaced all 4 wheel bearings, longer front wheel studs, steering rack bushing fix and more. Turns out one of my front wheel bearings had very minor play. Not sure if that was the culprit to my intermittent vibration. It’s still winter here, so in a week or 2, I’ll be able to drive the car and see if this issue is put to bed once and for all.

 

[Chris_Lum]

Chris, your videos made me go all out this winter. I’ve replaced all 4 wheel bearings, longer front wheel studs, steering rack bushing fix and more. Turns out one of my front wheel bearings had very minor play. Not sure if that was the culprit to my intermittent vibration. It’s still winter here, so in a week or 2, I’ll be able to drive the car and see if this issue is put to bed once and for all.

Crossing my fingers for you! Most everything I tried oddly had some type of temporary improvement to the steering shake, but it was never gone 100%. Most things I tried made the shaking go way maybe 85-90% at most, but would eventually come back completely. With the knock bushing, the steering wheel immediately felt rock solid at all times. It's a bit weird that the knock bushing fixing steering shake isn't a well documented thing on prime...I can't imagine it's a unique issue seeing as how many of us have/had the passenger knock noise along with steering shake. Even the nsx rack repair guys didn't think getting a knock bushing would solve my steering shake (which is why I didn't try it earlier). Feel free to post up in this thread if your car is fixed so we can know at least one of those things may have worked for you.

 

[dablackgoku1234]

So I finally took my car out for a lengthy drive. The steering wheel shake has been eliminated.

Things I did over the winter:
- changed all 4 wheel bearings
- steering rack bushing
- still using the same wheels and tires from before

With the steering rack bushing in place however, the steering is really stiff. I did lube the shaft before assembling everything back together, but still stiff when trying to turn. Will it loosen up over time?

 

[Chris_Lum]

So I finally took my car out for a lengthy drive. The steering wheel shake has been eliminated.

Things I did over the winter:
- changed all 4 wheel bearings
- steering rack bushing
- still using the same wheels and tires from before

With the steering rack bushing in place however, the steering is really stiff. I did lube the shaft before assembling everything back together, but still stiff when trying to turn. Will it loosen up over time?

Yes it will loosen up. Mine did within 100-200 miles.

 

[MrHugo]

Yes it will loosen up. Mine did within 100-200 miles.

First. Thanks for sharing all the valuable experience. I am sure these information will save other with same issues a lot of headache and money.

is the knock bushing same as what the steering rack bushing that someone else had mentioned ?

how is this bushing same as the NSX rack repair service provides ?

 

[Chris_Lum]

is the knock bushing same as what the steering rack bushing that someone else had mentioned ?

I'm not sure who mentioned it, but i would say "probably yes" they are the same. The proper distinction would be to call it a knock bushing though because there are actually other steering rack bushings that are completely different (rubber insulator pieces that mount between the rack and the chassis). So just depends on context...if they're talking about an alloy ring installed on the rack guide, then it's a "knock bushing."

how is this bushing same as the NSX rack repair service provides ?

It should be the same that they offer, although I'm sure they would say theirs is equal or superior at the least. I truly have no idea though because i haven't seen theirs as they don't sell it separately--only with their full rebuild.

 

[MrHugo]

I'm not sure who mentioned it, but i would say "probably yes" they are the same. The proper distinction would be to call it a knock bushing though because there are actually other steering rack bushings that are completely different (rubber insulator pieces that mount between the rack and the chassis). So just depends on context...if they're talking about an alloy ring installed on the rack guide, then it's a "knock bushing."


It should be the same that they offer, although I'm sure they would say theirs is equal or superior at the least. I truly have no idea though because i haven't seen theirs as they don't sell it separately--only with their full rebuild.

Thanks, I just watched your video to install the bushing. Great video btw! The only part I am afraid of tackling it myself is the ball joint. Which tool would you recommend to use to pop the ball joint? I know Honda makes one but that one is expensive.

Also, do i need an alignment after the installation?

 

[Chris_Lum]

Thanks, I just watched your video to install the bushing. Great video btw! The only part I am afraid of tackling it myself is the ball joint. Which tool would you recommend to use to pop the ball joint? I know Honda makes one but that one is expensive.

Also, do i need an alignment after the installation?

The ball joint tool i'm using is "OEM Tools" brand, linked in the description of my video. If you do it the way i did in my video and pop the ball joint on the tie rod end and leave it attached to the inner tie rod, then you will not need to get an alignment when done because all the adjustment is done between the outer and inner tie rods.

 

[RYU]

Sorry, this is a going to be a little OT for this thread but this time I can say I didn't start it! lol
[MENTION=23169]MrHugo[/MENTION] - I'm going through a full suspension overhaul now. It's taking me weeks since i'm taking my time. I'm installing all of the prothane parts because of a lack of options. [MENTION=36904]Chris_Lum[/MENTION] has been super generous with his time time in helping me press out the front bushings (thanks heaps Chris!). I'm already going through modifications required to make the prothane bushings work properly (I hope) which I will post here on prime. The Prothane kit definitely is not a plug and play affair but if the modifications are made i'm guessing it ought to work properly even for a high abuse track car. Thanks to Chris and [MENTION=18194]Honcho[/MENTION] and AJ for sheding some light into their challenges.

Here's part 1 of my Prothane bushing modifications. I had to mill off a tapered shoulder on the front bushings. More lathe work to do later this week for the rears.

https://youtube.com/shorts/3jHaACQcrwY?feature=share

In terms of alignment if you're removing the inner camber bolts of the front and/or rear lower control arms you will probably need an alignment unless you're really good with making marks on the cam bolts. However, if you have new bushings there's a tiny chance that the stiffness of the new bushings might also yield slightly different alignment specs once the car is on the ground under it's own weight (old rubber vs new urethane bushing deflection or what not).

On the ball joints I'm having to get creative with the tools I use. The standard ball joint you can buy on Amazon can't always fit in the tight places. For example, this one shown in the video for the rear lowers.

FYI: I'm having a set of AS Motorsports ball joints shipped to me. I had found my lower rears were nearly worn past acceptable.

https://youtube.com/shorts/4ahjX6Kv2qA

 

[MrHugo]

Sorry, this is a going to be a little OT for this thread but this time I can say I didn't start it! lol
@MrHugo - I'm going through a full suspension overhaul now. It's taking me weeks since i'm taking my time. I'm installing all of the prothane parts because of a lack of options. @Chris_Lum has been super generous with his time time in helping me press out the front bushings (thanks heaps Chris!). I'm already going through modifications required to make the prothane bushings work properly (I hope) which I will post here on prime. The Prothane kit definitely is not a plug and play affair but if the modifications are made i'm guessing it ought to work properly even for a high abuse track car. Thanks to Chris and @Honcho and AJ for sheding some light into their challenges.

Here's part 1 of my Prothane bushing modifications. I had to mill off a tapered shoulder on the front bushings. More lathe work to do later this week for the rears.

https://youtube.com/shorts/3jHaACQcrwY?feature=share

In terms of alignment if you're removing the inner camber bolts of the front and/or rear lower control arms you will probably need an alignment unless you're really good with making marks on the cam bolts. However, if you have new bushings there's a tiny chance that the stiffness of the new bushings might also yield slightly different alignment specs once the car is on the ground under it's own weight (old rubber vs new urethane bushing deflection or what not).

On the ball joints I'm having to get creative with the tools I use. The standard ball joint you can buy on Amazon can't always fit in the tight places. For example, this one shown in the video for the rear lowers.

FYI: I'm having a set of AS Motorsports ball joints shipped to me. I had found my lower rears were nearly worn past acceptable.

https://youtube.com/shorts/4ahjX6Kv2qA

Thanks Chris and Regan for the insights. I think it will be safer just to get another alignment after the bushing is installed. It will be a good time for me to adjust my ride height.