I have a nail in one tire of my sequoia. Do I need to replace all

It is just the brand of tires some hum some don't the more you pay the leless noise you get.

Try rotating both front wheels to the back one at a time. If a tire has a bad belt; it may balanced but balancing does not eliminate a soft spot on the tire tread. By moving the tires to the back and road testing it after each side is done, you may be able to find the bad tire.

You have a lot of moving parts. A brake rotor could be out of balance, you can have a worn CV joint shaft, a hub bearing could be worn, driveshafts and U-joints can shake.

If you do find one wheel as a problem, have the tire dismounted and the wheel spun on the machine. You may have a bent rim and the tire may be good. Since the balance would help compensate for the vibration, it can mask the flattened spot on the rim. The tire will act like a shock absorber but ultimately the rim is not turning like it is round once weight is on it.

I would be interested in what you found.

check for a screw or nail stuck in your tire. other causes would be loose lug nuts, or noisey hub caps ( you probably dont have those ). you can roll down the windows and have a helper identify the location of the noise. roll down a safe street and put in neutral, turn key to off - for gods sake dont lock up the steering wheel!!!! try to pinpoint which corner of the car noise is coming from. A bad CV joint would make a tapping-clanking noise but mostly when turning.

the oil sending unit is located beside the oil filter,it screws into the engine,don't know if your hearing a serp belt squeal,
check tire pressure for the for steering problem or a bad tire that a steel belt has shifted

The actual caster spec is not very significant - the handling is what counts. The caster will not cause a shimmy. Shimmy could be caused by tire problems, worn or damaged steering or suspension parts, bad shock absorbers or a bent wheel. As long as the vehicle does not pull and the handling is satisfactory, the caster is OK, If the tires are not wearing and the vehicle hamdles OK - don't worry about "specs." I have done a LOT of alignments where the readings did not match the specs, but the result was satisfactory.

All car manufactures do this 30,000 mile tires only to add 4 tires that cost 100.000 each and sell 1000 cars would cost them 40,000 dollors and a million times 4 would be 4 million times 100.00 dollars you get the picture? 40 million dollars for tires. When I got my new truck I ordered better tires and it cost me $150.00 to upgrade to 50,000 tires. you pay for what you get.

Your tires have pressure/temp sensors in them. Even the spare tire. Set them all at 35lbs. Most times people forget about the spare and it keeps the light on. Turn the key on and wait about 2 mins. The light should go out. Some Sequoias have a reset button under the steering wheel on the bottom of the dash. This sets the low pressure threshold and only needs to be reset if memory was scrambled somehow. Rare so don't worry about that now. If the light blinks on startup its possible you have a bad sensor in one of the tires and will need to checked at the dealer.
The MAINT light is reset with the little stem button you use to change the odometer from odo to trip 1 or 2. Set it to odo and turn the truck off. Push and hold the button while turning the key to on. The display will show -------------- Keep holding it until it changes to 0000000. The its reset for another 5k miles.

If you had the 30,000 mile maintenance done, nothing of any real importance, just oil change, tire rotation, check air filter, check all fluids, tire pressures, etc. 30-60-90 K miles are important.

need to replace the strut

first check condition of discs and pads if all is good drive and pull up handbrake slowly to see if its the handbrake shoes making the noise if still a problem will most probably be rear wheel bearings