oil pan gasket, maybe rear main seal?

We used our 4 wd and later that day all the buttons went out and said service 4wd. I had to have it towed home because it was clicking and grinding when we were driving. I'm hoping someone can help. I miss driving my suburban

Before it kicks itself into 4 low the neutral light comes on and the service 4WD indicator lights up. It takes some time but eventually you can switch it back out by putting the vehicle in neutral or park and pressing the 2H button several times. This happens about every 2-3 months. Any idea what can cause this?

I have changed fuses, relays with the fuse panel, PCM module itself, changed batteries, and did all that I known to do. I beginning to wonder if it is dealing with my fuel relay, or is there a short somewhere. Its giving me the blues. I have not dropped the tank or changed the relay to the fuel. I need the specs on that to trace wires and relays. 25amp fuse out and vehicle will turn but never start. I am lost.

Every day I have to put power steering fluid in my truck because it's leaking bad and sometimes my brakes act like they don't want to work when the fluid is low. There is a loud whining sound when I turn,drive,or even put my foot on the brakes. What do I need fixed? Please help!

Where_is_the_orifice_tube_in_a_2005_Chevy_Suburban w/rear ac

Last Friday I turned my Saburban on and put it into drive. Everything was fine as I drove a short distance, until came to a complete stop at a red light. As the light changed to green, I released the brake to creep forward to allow on coming vehicles to pass before attempting my left turn.

As the last on coming car passed me by, I steppe on the accelerator, but the vehicle would not move forward. I could hear some grinding, then suddenly, it felt as if I had been hit hard from behind and my Saburban jerked forward and was now able drive.

I pulled over to exchange documents with the person who had hit me, but to my surprise, no one had hit me and there was no damage to my vehicle, nor was there any car behind me as I felt the strong forward jerk.

So, the problem lies with the vehicle.
1.) Why would it not engage as I stepped on the gas pedal?
2.) Why did I hear a loud grinding sound?
3.) What may have caused the strong push forward?

If you have any ideas as to what the issue(s) may be, please advise?

While driving the truck will just stop - no warning - just dead. I roll to the side of the road and try to start it - sometimes it starts and sometimes it won't. It just dies when it wants to - no warning lights come on. What's up with this? Had the fuel sender replaced but still happens - any ideas as to why?

Should I also replace knock sensors?

Ever since the dealer performed 100k scheduled mait. at about 130k, Ive been having engine noise that I didn't have before. I take good care of my car and other than this noise, it sounds like the engine is still running well and strong at 165k. After the mait., I complained and they changed the oil. After that I noticed that my oil pressure was running high so I checked it and it was overfilled. I took it back to the dealer and they drained some but didn't measure how much it was over. Could this have caused the problem. Maybe the oil pump is going out? Whatever you can help with will be appreciated. Thank you.