first off sorry this is so long just needed to get all the info in this. so i have a 2002 dodge ram 1500 SLT Lonestar edition with the 4.7l 2 wheel drive, and my brake and abs lights are turning on at the same time on ramdom speeds. it used to start at 80mph on the dot, i had the codes scanned and code 37 "intermittent signal/Rear sensor" came up, so i assumed it was the rear wheel speed senor in the diff going out cause its original and 14 years old. so i put the new one in and now the lights are turning on at 45mph or 50mph so i cleaned the old one to put it back in cause it wouldnt go on unless i go highway speeds, but i found a huge chunk missing so i removed the diff cover and took a look inside and found a **** load of metal shavings removed them and found chunks of metal the size of my nails sitting in there and thought they were flying around and hit the sensor and that made it go off, then i noticed the teeth on the diff gears were also chipped. didnt rotate gears all the way around to inspect it because im a dumbass, but i did notice some huge *** gouges on the diff cover from the inside on the left side of the cover if you were to look at it when its on. but the lights still turn on and now im just annoyed after all this is when the damn lights turn on at random speeds, like this morning was 46mph and when i got off work today it was 80mph but i was going 80 for a while before the lights turned on, like something else is triggering it and also my speedo needle is all jumpy and not steady

 

this is the 3rd gen 02 not the 2nd gen 02

 

Definitely sounds like you have differential issues. My guess is the sensor is not getting a proper signal from the ring gear assembly...be it because of the shavings and metal particles you have found or damage inside the housing or carrier. Im surprised you haven't mentioned anything about rear diff noise.....?

 

i used to hear a weird loud noise when i change from park to drive or park to reverse, even reverse to drive and drive to reverse. kinda like a meeerrch eench noise if i had to spell it, is that the noise you speak of? but it went away when i changed the fluid and cleaned the shavings out, last time this was done was at 75k miles now im at 208k

 

idk if you get a alert when quoted or not

 

Hard to diagnose this over Internet
You could have more than one issue. One problem may be causing your code 37. The other issue....from how you describe broken gear teeth and chunks of metal in the differential housing definitely indicates a tear down and inspection of the rear differential is definitely required and sooner than later !
because you definitely have an issue in the rear end housing and your code is related to the rear end housing i would start by having the rear diff examined by a qualified person with experience in this type of repair and rebuild.

 

i went a described this to the technician at the dodge dealership and he said it sounds like my differential is falling apart. he said the bolt holding the pinion could be loose and causing the gears to move up and down or the wheel bearings are gone and the differential is moving all over the place and that it could be both of these things. and since i found some of the speed sensor missing and the scraches on the diff cover sounds like bearings more then the bolt being loose, but one thing i know for sure is that i need new gears. what is everything that i need?

 

You wont know until you get it apart. Most likely at the least 2 pinion bearings a seal and nut. 2 carrier bearings. Ring and pinion gear set. With the miles most likely needs posi trac clutch pac if yours is equipped with this option. Parts alone easily $500. You may wish to look for a complete used differential.