The Mechanical Advice Thread

[Klobbersaurus]

Originally Posted by twitchyzero

So I was getting light vibration in the steering wheel when braking from high speeds. I might've also been due for an alignment because car didn't drive all that straight.
Few days ago I did my front discs/pads (raybestos professional grade discs and akebono pro-acts) and now I'm getting worse vibration at 60kph+ and when I'm going down a hill. Car also pulls to the right (worse alignment than before) when I let go of the wheel.

Pretty sure my rotors are seated correctly. First chance I get is to check lug torque but they're not loose. How important is it to torque all the caliper bolts to specs? I did the exact same job in the rears and ran them problem free for a week. Don't know if this makes a diff but the brake fluid was a bit over max line in the reservoir after I pushed the caliper pistons back. Tire pressure is good just a week ago. What else could be a culprit? Wheel weights? I was told to put back my old rotors to see if the new problem goes away.

when your braking, does the pedal pulsate or the pedal and steering wheel? if its just the pedal, most likely your rear rotors, if the steering wheel shakes, then its your front rotors or does it only shake when your driving

did you clean the hub when you put on the new rotors?

[twitchyzero]

it's definitely the front
it shakes when I'm driving highway speeds or going down a hill. Be it accelerating/braking/neither.
yes I used brake clean on the hub surface...used wirebrush as well on the right side.

[Tone Loc]

Got my wheels balanced at Fountain Tire, as I experienced a really bad shaking around 110 kph. The truck tracked straight and had no "abnormal" tire wear, so I figured an alignment would not be necessary. They used one of those Hunter "Road Force" balancers, which I am told from several different sources are the best in the business.

After the balancing, the truck doesn't shake as bad but now the steering wheel shakes at roughly the same speed of 110. Going to about 140 and the shaking gets really bad. Not such a big deal as I never drive that fast, ever. The shaking is mostly gone except for on the steering wheel. I remove my hands from the wheel and the truck still tracks straight.

What gives? I am going to get an alignment later this month after doing my tie roads and lower ball joints so hopefully this fixes it.

All the tire tech told me was that my "wheels were really out of balance"...

[hud 91gt]

Originally Posted by underscore

Now the vibration moves around, sometimes it goes way while cornering at speed, this morning it started at 80, stopped at 90, started at 100, stopped at 100...what the ever loving fuck.

Was there a weight missing?

[underscore]

I haven't had a chance to get it checked yet, I've been too busy with work. I'm thinking that weights missing off multiple wheels would explain why the vibration keeps occurring at different speeds

[Klobbersaurus]

Originally Posted by twitchyzero

it's definitely the front
it shakes when I'm driving highway speeds or going down a hill. Be it accelerating/braking/neither.
yes I used brake clean on the hub surface...used wirebrush as well on the right side.

sounds like a bad rotor, grab a dial indicator and check the run out

[see.lai]

Originally Posted by twitchyzero

it's definitely the front
it shakes when I'm driving highway speeds or going down a hill. Be it accelerating/braking/neither.
yes I used brake clean on the hub surface...used wirebrush as well on the right side.

So you're driving over 80km/hr and your steering wheel is shaking more violent than before, even with the new brakes that you've put on? Check to see if the screw that holds onto the rotor is in the correct hole (the tapered one).

I'm pretty sure your brand new rotors aren't out of round.

Also check wheel balance, in case.

[i-vtecyo]

dont wanna start a new thread for this but is it shady for a body shop to take a deposit prior to performing any work? I brought my car to a body shop to get both rocker panels fixed for $700.

[dared3vil0]

^ Seems a bit weird for something so minor...

[dn53]

Originally Posted by twitchyzero

it's definitely the front
it shakes when I'm driving highway speeds or going down a hill. Be it accelerating/braking/neither.
yes I used brake clean on the hub surface...used wirebrush as well on the right side.

Couple ways I'd approach this issue. I think you may have a combination of multiple issues which

1) measure run out on the rotor (my guess is you don't have a dial indicator , not many people do).

2) rotate the tires front to rear, and after side to side. If this affects your pulling or steering wheel shake, you most likely have a balance /tire issue.

3)break in the pads again. How was the car driven since you put the pads and rotors in? I rec light driving for at least 100k until you really step on it. You can attempt sanding down the pads and cross hatching the rotors using sandpaper. Did you clean the rotors surface before installation? There is a coating of oil put on the rotors to prevent it from rusting on the shelf.

You can do step two and three together. Make sure you lubricate the slider pins with slider pin grease (lordco has sylglyde)

[dn53]

Originally Posted by FunkyColdMedina

Got my wheels balanced at Fountain Tire, as I experienced a really bad shaking around 110 kph. The truck tracked straight and had no "abnormal" tire wear, so I figured an alignment would not be necessary. They used one of those Hunter "Road Force" balancers, which I am told from several different sources are the best in the business.

After the balancing, the truck doesn't shake as bad but now the steering wheel shakes at roughly the same speed of 110. Going to about 140 and the shaking gets really bad. Not such a big deal as I never drive that fast, ever. The shaking is mostly gone except for on the steering wheel. I remove my hands from the wheel and the truck still tracks straight.

What gives? I am going to get an alignment later this month after doing my tie roads and lower ball joints so hopefully this fixes it.

All the tire tech told me was that my "wheels were really out of balance"...

Any bends or dips in the rims? Weights can only do so much. Does your wheels have a lip for the weights to be fastened or is it sticky weights? If they are sticky, they may have fallen off. Have them double check the balance. Are these factory wheels on stock suspension?

[twitchyzero]

Originally Posted by Klobbersaurus

sounds like a bad rotor, grab a dial indicator and check the run out

Originally Posted by see.lai

So you're driving over 80km/hr and your steering wheel is shaking more violent than before, even with the new brakes that you've put on? Check to see if the screw that holds onto the rotor is in the correct hole (the tapered one).

I'm pretty sure your brand new rotors aren't out of round.

Also check wheel balance, in case.

Originally Posted by dn53

Couple ways I'd approach this issue. I think you may have a combination of multiple issues which

1) measure run out on the rotor (my guess is you don't have a dial indicator , not many people do).

2) rotate the tires front to rear, and after side to side. If this affects your pulling or steering wheel shake, you most likely have a balance /tire issue.

3)break in the pads again. How was the car driven since you put the pads and rotors in? I rec light driving for at least 100k until you really step on it. You can attempt sanding down the pads and cross hatching the rotors using sandpaper. Did you clean the rotors surface before installation? There is a coating of oil put on the rotors to prevent it from rusting on the shelf.

You can do step two and three together. Make sure you lubricate the slider pins with slider pin grease (lordco has sylglyde)

didn't invest in a dial indcator because most people suggested it's overkill. If it's truly bad rotors then i'd get the mfg to replace them.

yes rotors were cleaned before mounting. yes slide pins were greased. I'm aware of akebono's recommended 400-500mi bedding process and I usually throttle/brake like a grandma anyways.

I think I ensured the rotor screws went into the correct holes but one wasn't completely flush because of the rust on the threads. Didn't think much of it because these screws are apparently optional.

wheels are directional and i just rotated them 6 mo ago. How do I check the wheel balance? As long as the weights look the same on both wheels?

when installing pads do you have it resting against the rotor surface or have a bit of gap and have it sit towards the outer edge of the caliper bracket? I didn't think it'd make a difference because once you brake the pads will just rest on the rotors?

[The_AK]

Question - can mass air flow sensor cleaner be used in place of brake cleaner? iirc MAF cleaner doesnt leave any residue so i would assume safe?

[dn53]

Originally Posted by twitchyzero

didn't invest in a dial indcator because most people suggested it's overkill. If it's truly bad rotors then i'd get the mfg to replace them.

yes rotors were cleaned before mounting. yes slide pins were greased. I'm aware of akebono's recommended 400-500mi bedding process and I usually throttle/brake like a grandma anyways.

I think I ensured the rotor screws went into the correct holes but one wasn't completely flush because of the rust on the threads. Didn't think much of it because these screws are apparently optional.

wheels are directional and i just rotated them 6 mo ago. How do I check the wheel balance? As long as the weights look the same on both wheels?

when installing pads do you have it resting against the rotor surface or have a bit of gap and have it sit towards the outer edge of the caliper bracket? I didn't think it'd make a difference because once you brake the pads will just rest on the rotors?

Tire balance must be checked by a machine, there's no way to eye ball them. When you balance a tire, you are balancing that individual rim, not the balance between the two adjacent tires.

You can move the tires front to rear to see if it makes any difference since the front tires will cause a much more harsher vibration than the rear.

the piston will take up pad slack so it doesnt really matter. that screw just helps you with installation. you mention that you werent able to thread the screw all the way in -- did you leave it out? i would imagine if that screw is not in all the way it can cause a wobble if its in direct contact with the rim mounting surface (small chance.. but hey just maybe?).

[inv4zn]

Strange sound coming from front driver's wheel area.

It sounds like a "shik-shik-shik", frequency increases with speed, drowned out/gone at 40+km/h.

New tires were installed last Monday, didn't notice this sound.
On Saturday, I took said wheel off to install CAI, reinstalled, torqued then and again this morning.

Car does not pull, nor is there smell, so I'm assuming brake isn't dragging.
Wheel weights and lugnuts checked.

I can lift the car again to check for play in wheel bearing, and to check if rotor shield was bent or something, but does somebody have any other ideas?

I saw "defective tire" thrown around, but (I think) it was fine for the first week or so.

[fliptuner]

See if the backing plate is grazing the rotor? If so, push it away a bit.

[twitchyzero]

Originally Posted by twitchyzero

I think I ensured the rotor screws went into the correct holes but one wasn't completely flush because of the rust on the threads. Didn't think much of it because these screws are apparently optional.

Originally Posted by dn53

you mention that you werent able to thread the screw all the way in -- did you leave it out? i would imagine if that screw is not in all the way it can cause a wobble if its in direct contact with the rim mounting surface (small chance.. but hey just maybe?).

the alignment screws were slightly bent
took them out..problem solved
total moment

[josel_atr]

hello. might be a long shot but im looking for garage space for my friend who is a mobile mechanic. he is doing a timing belt job on my car.

hes got everything in his van from tools to air compressor and i got all the parts needed for the job. we just need a space and a roof over it. it will be raining for the rest of the week.

i live in a apartment building where they dont allow renters to work on our own cars.

ps. we are not crazy. dont worry. ill bring you beer. corona?

another ps. we are in burnaby by patterson station. anywere in the 10km radius is fine

[thumper]

not sure if this is the right place to ask, but what do you guys use for fuel system cleaner? i've used my last bottle of chevron techron and i can't find it anymore at the chevron gas stations locally. or something that has PEA detergent in it? my mechanic suggested gumout regane but i haven't been able to find that either, aside from the inferior one they sell at walmart?

[danny_d19]

Seafoam ^

[IMASA]

They sell Gumout Regane at Canadian Tire and surprisingly at some Safeway locations, at least the one at King Ed and Oak.

I use Redline S1

[multicartual]

302 + T5

[ironheader]

Originally Posted by thumper

not sure if this is the right place to ask, but what do you guys use for fuel system cleaner? i've used my last bottle of chevron techron and i can't find it anymore at the chevron gas stations locally. or something that has PEA detergent in it? my mechanic suggested gumout regane but i haven't been able to find that either, aside from the inferior one they sell at walmart?

Motomaster Engine Treatment, on sale this week, in a metal can like seafoam.

[thumper]

is this stuff going to smoke up the entire neighborhood? it's a little early in the year for me to blame the mosquitoes

[godwin]

Just say it is fog

Originally Posted by thumper

is this stuff going to smoke up the entire neighborhood? it's a little early in the year for me to blame the mosquitoes