If i take the ABS fuse out, nothing bad will happen?

When i first got the truck, the rear differential was bone dry, i added valvoline w90 gear oil and its not as loud, but its too loud. When i press on the gas it sounds like an airplane. When you take your foot off the gas, the noise goes away. My dad was tellin me that the differential was fine, just needed a bit more clearance. I don't understand diffs, so i will take his word for it. I understand a lil noise, cause its an old truck, but not like this. I found a good 3rd member for 70 bucks, i think I am gonna swap it, i hope that gets rid of the noise. ill also change to the 140 gear oil..

It is a lifter noise, but i don't understand if its a bad lifter how can it charge once in a while? i just drove it right now and the motor purred like a kitten. Thought wow, maybe the oil worked. Started it right back up, then the noise came back.

I have a whole tray of brand new lifters, changing them is not the problem, i just want to make sure that if i do it the noise is going to go away. Do you think i should change the rocker arms and the pushrods as well? The noise is coming from the right head, not both..

As far as the engine oil, When we rebuild motors, we use straight 30 and tell them to change it after the first 100 miles, i should have put this in the first time, but i'm an idiot. A shop manager at BMW i know told me to use 5w-20. I have the 5w-40 in there now, so i think im good on that front.

The 4x4 shifter is locked also, do you think that is a linkage problem? I have so many little problems here and there, don't want to bother you guys with it all at once, so thanx for the replies, i appreciate it..

When you open it up, don't just replacing lifters, inspect each one for wear as well as the cam lobe, inspect the ends of each push rod for wear and measure each for length. remove and inspect the rocker shaft and arms checking for wear.

The motor was a complete rebuild..The only things i ended up re-using were 4 push rods and the rocker arms, rockers. They looked cherry, they were used, but very little wear if any...

edit: also reused the pistons from the DII, they were spotless...It was a very low mileage motor, came out of a salvage vehicle..

Does the noise only on startup or is it again during idling? I don't recall but did you say you rebuilt the cylinder heads also?

Heads were completley rebuilt. It makes the noise in idle, but on and off...For example I started up this morning drove to work, the noise was there at every stop light. My way back home, noise was gone, even in idle. I shut it off and started it back on again, thinking its fixed, the noise came back..

Maybe one of the rockers are loose?

Ok you are totally not getting what I am saying, it's NOT a bad lifter, it is a bad rocker arm.
Like I said before on the DII engine, which what you said you have, the rocker arms have tin caps inside the cups that the lifters go into.
Those tin caps are welded in, the welds break over time and then they rattle around sounding like a bad lifter.
Start by checking your rocker arms for correct clearance and torque, if the noise continues then I would replace the rocker arms.

If you pull the ABS fuse from under the hood all that is going to happen is your truck will self destruct.
Seriously, you wont have ABS, thats it, nothing else will happen, if you know anything about ABS then you know your brakes will work just fine.

As for the diff, it is toast, that airplane sound when you press the gas is the gears going south.
Eventually you wont be able to stand driving the truck because the noise will be so loud.

Maybe, that is tough one to diagnose. As long as your oil pressure is OK you are probably fine but I understand that after all that work to have a tick would eat at you. The next step would be to take off the IMs's and rocker covers and take another look at everything like spike said.

Thanks alot man, i really appreciate the explanation. I am going to open up the valve covers this weekend and check it out. ill just swap out the diff also. We don't have a lift in the shop so its going to be a pain..

I thought the ABS had something to do with the engine code, ill just pop out the fuse.

Do you have a general idea why the 4x4 shifter would be stuck? You think its the linkage? or the transfer case? i have a gearbox code and i think i'm going to start with checking the wiring to the control box before i do anything major.

The ABS and OBDII are two separate systems each with their own ECM.

As for the transfer case, it could either be a frozen linkage or a bad solenoid, if it is the latter you can just remove it and forget it.

You dont need to do anything more than put the axle on jack stands to replace the diff, remove the drive shaft, pull the axle shafts out part way (you can even leave the wheels on) and then unbolt the diff and drop it out, then put in the "new" one.

Disco's are designed to be repaired in the jungle, almost everything is easy to get to and comes out as one piece after undoing a couple of bolts.

You are the man Spike, Mike and Lipad, thank you for your help...I feel much better now :)