45
votes
Accepted
Why do the brakes "freeze" the suspension?
I made a crude sketch illustrating the relevant points of the shown image.
Brakes engaged:
The center of gravity is above ground, the brakes "try" to slow down the car, the car itself "...
- 8,448
27
votes
Broken Coil Spring - How urgent is the repair?
That spring can rotate and rip out the tire - catastrophic loss when entering a bend could mean driver, occupants, other drivers, and/or bystanders could be singing with the angels...
Ground the car ...
- 34.7k
21
votes
Accepted
Discovered disconnected part when removing wheels
I agree with @resident_heretic that these are the link arms for your stabilizer bars. The bar acts as a torsion spring that tends to keep the car level during cornering.
With the links broken on the ...
- 14.4k
16
votes
Accepted
Motorcycle Speed Wobble - How do I figure out the problem?
Motorcycle Speed Wobble Troubleshooting
Troubleshooting speed wobbles can entail looking at quite a bit. Here are some bullet points on components you need to check on your bike for integrity and ...
- 33k
16
votes
Broken Coil Spring - How urgent is the repair?
My biggest concern with issues like this is causing additional damage since the spring is no longer being supported the way it was designed to be.
Also, the rear suspension is (obviously) compromised,...
- 12.1k
15
votes
Accepted
Reusing self locking nuts
I'll make a couple of cogent points, but I doubt I'll be able to organize this coherently.
Go get and read Carrol Smith's Nuts Bolts Fasteners and Plumbing. This is religious tome-level knowledge ...
- 12.4k
14
votes
Accepted
Spring tensioner safety
I use two part spring compressors like you show here on a regular basis.* I think you'll be fine but there are some good things to watch out for.
Watch out for the threads. If the compressing ...
- 24.3k
14
votes
Discovered disconnected part when removing wheels
Looks like a stabilizer bar link. They come in pairs one on the left and one on the right side. They attach to the stabilizer bar. Stabilizer bars are part of a car's suspension system. They are ...
- 3,917
14
votes
Accepted
Vibration at speeds between 40-47mph
Hitting a bump at speed can cause several problems:
Tire or wheel damage: generally this requires a replacement tire or wheel
Suspension damage: a suspension member could have been bent or damaged by ...
- 16.2k
13
votes
Broken Coil Spring - How urgent is the repair?
The basic issue from a mechanical point of view is that the spring (not the shock!) is what supports the weight of that corner of the car. Clearly, with a piece missing, it is not doing that as it was ...
- 2,954
11
votes
Accepted
How Urgent is it to Replace Worn Out CV Boots
From my experience of CV boots, you need to replace them immediately if you want to keep the CV joint it covers. It doesn't take long for dirt to destroy the joint once it gets inside the boot. If ...
- 24.9k
11
votes
Accepted
What are the advantages of upside down forks?
There are several advantages to upside down forks
Rigidity
Caliper Mounting
Stability
Reduced Unsprung Weight
Reduced Sprung Weight
Reduced Stanchion Friction Levels
Increased Stanchion to Slider ...
- 33k
11
votes
Pros and cons lowering sedan?
For God's sake don't
I'm still to see a car that was lowered properly. From what I can remember now you will have these issues:
The car will jump at every small irregularity in the asphalt.
Wheels ...
- 1,739
11
votes
Why do race cars need suspension?
Suspensions do two things:
they smooth out a bumpy ride, and as such are more of a comfort thing. In fact, production cars have their suspensions tuned at the factory for some kind of compromise ...
- 12.2k
11
votes
Accepted
Is alignment needed after replacing upper control arms?
ABSOLUTELY
Yes, when you do any major work to the front suspension, you need to have the alignment done. Even though the parts are "basically" the same, they are not exact. Newer parts will be ...
- 153k
10
votes
Accepted
Effects of sway bar stiffness on rough, uneven roads
tl;dr: stiffening one of the sway bars on a car will cause that end to be more likely break loose in response to transients.
At a high level, the sway bar acts as a spring just like any other. You ...
- 24.3k
10
votes
Accepted
Wish to understand why non-stock vehicle alignment is an issue
Factory specs assume factory parts. Each modification you have made changes the angles at which the suspension operates so those angles no longer apply. This is especially true on truck lifts where a ...
- 661
10
votes
Why do the brakes "freeze" the suspension?
As it turns out the answer is very obvious and frankly quite simple.
Consider a 1 meter long plank.
Now if you lift up the right side of the plank by 10 cm (0.1 meter), the left side moves a bit to ...
- 1,344
9
votes
Accepted
What makes a worn car shock spongy and soft?
Shocks/struts can either come charged with nitrogen (gas shock) or conventional (without a charge). Both can wear out over time. Shocks should be replaced around 50k miles under normal conditions. ...
- 153k
9
votes
Accepted
"Always Replace" (torque-to-yield) Bolts
I cannot tell you directly if the bolts you are using are Torque to Yield (TTY or T2Y) bolts, but if Bently says to replace them, you bet I'd do it. What are three bolts in comparison to the well ...
- 153k
9
votes
Accepted
How did luxury cars provide smoother rides without active suspensions?
Assuming they were the base models, the two cars you mentioned (Acura TL and Mazda6) are both Front-Wheel Drive (FWD), while the Mercedes is Rear-Wheel Drive (RWD). The FWD cars, having both their ...
- 6,037
9
votes
How to demonstrate that rear shocks are failing?
There should be no oil visible on the shocks. If you see oil that means they're not damping as they should be because the seals are compromised. They most certainly shouldn't be dripping, regardless ...
- 39.1k
9
votes
When to replace struts?
Those look very worn to me. Of course it's your choice, unless your locality requires vehicle safety inspections, to keep driving on worn suspension parts but it's not the safe choice.
The fact that ...
- 12.1k
8
votes
Load on bed of pickup for extended period of time
Your truck is designed to carry that load. If you consider carrying a full set of passengers. 1 in the front, 3 in the back, that weight would exceed your current load of 500 pounds. I would not be ...
- 33k
8
votes
Accepted
Ohlins Rear Motorcycle Shock - How do I setup, care for and tune it?
Overview
In terms of rebuilding the shock, there are similarities between models but there are unique differences between them that make it impossible to review all of the nuance. I'll only give a ...
- 33k
8
votes
Effects of sway bar stiffness on rough, uneven roads
Adding a sway bar will result in a harsher ride
I've tried to explain the mechanics with this side-by-side graphic:
Explanation
When a wheel encounters a ditch, the weight of the vehicle on that ...
- 39.1k
8
votes
Accepted
What is the difference between a knuckle and spindle?
The knuckle is the part the spindle attaches to. The spindle carries the hub and bearing(s). Generally the spindle is used on non-driven wheels, but there are some where the spindle is hollow and the ...
- 10.7k
8
votes
Accepted
Torquing Strut Nut with Tire on Ground
You should leave them just about snug, if not just a little loose. If you tighten them before you put it on the ground, when you do get the car on the ground, there will be tension on the parts, which ...
- 153k
7
votes
Accepted
How bad is this strut mount damage?
Strut mounts that tear a little are safe to drive with. The mounts themselves have metal inside them and are conically shaped at the top so they really won't fail unless you take the vehicle airborne ...
- 3,343
7
votes
Why are shock absorbers in wishbone suspension systems mounted on the lower control arm?
The late 60s to early 70s mustangs has shocks and springs on the upper control arms.
Normally They are installed on the lower control arm to save space. By fitting them between the control arms the ...
- 16k
Only top scored, non community-wiki answers of a minimum length are eligible