Ok cool, that's what that mgd41 is, white lithium grease

 

I say it is the beginning of a u-joint going bad, it will get worse and will make that noise anytime the truck is rolling, right now it takes the torque to cause it. grease the fittings in the u-joints on rear drive shaft first. if it continues you probably have a bad u-joint

 

How much is that gonna run to have replaced if that is the problem??

 

Id say its a u joint too..... That sounds similar to the problem i started with and i kept driving on it because i had no time mess with it because it was late fall and baseball took up most of any free time i had besides school...... long story short, just yesterday i got the driveshaft off and where the u joint connects to the yoke/differential it literally destroyed the yoke where it connects to the differential at. Theres a chunk of metal missing and its cracked. My truck vibrated at speeds over 50 real bad and all other symptoms of a bad u joint and im glad i at-least am changing it now instead of on the highway

My advice would be to change the u joint while it hasnt damaged the yoke, the yoke was only 70 bucks from the dealership but it beats having to pay that at all (plus having to wait for it because no one carries it).... oh and my u joint looks like it came from hell and back with one of the caps halfway tore off and all of the bearings missing out of some sides of the u joint...... If you want pics just hollar at me and ill post them tomorrow since ill be finishing the job tomorrow and i have a camera with me


one u joint costs like 16 bucks at the most, even for a grease-able one

 

Yeah do you have any pics that I could compare to what I see under my truck?

 

Update:

Today before i went to work this morning I got under her and sprayed some penetrating oil on the ujoint(s)...I tested it out and it didn't make the noise when I floored it. I was happy.

However, when I got off it was doing it again. I was talking to my dad about it and he was telling me that the penetrating is like a smaller consistency so it probably dried out really quickly or got "blown" off in a sense. He showed me some better, thicker grease that we had in the garage that I couldn't find this morning so I just went out and sprayed that on there. Gonna go see if it helped in a bit. Will update you guys when I do

 

i have a similiar problem but i think mine may be more tranny related. it only happens at wide open throttle and when it shifts it makes a horrible screech my friends ford dose the same thing and he says its a belt

 

Man where are your brains?!? the grease goes in the u-joint not on it. these are crafted pieces with internal crevices that"feed" grease into the caps which in turn allow the drive shaft to move up and down while spinning at a extreme velocity. Cudos you found a way to locate the problem now stop wasting grease and get that thing replaced soon!!!

Ps. that whine you hear is metal too metal grind never good in any situation.

 

It's not like a metal to metal whine though. I don't really know how to describe it. and I don't know how to get the grease into the u-joint? lol. Someone said something about a nipple but I couldn't see one anywhere so I just figured I was supposed to spray it on there in the crevices and ****. Do you know where I am supposed to put it? I will prob end up replacing it anyway, but I would like to grease it up until I do.

Either way, the noise got a little quieter, although it is still there. I thought maybe I just didnt get enough on there, but now you're saying I did it wrong so idk. It also strikes me as odd that it was completely gone this morning. The only thing I could think of for that is that it was kinda cold this morning so expansion/shrinking due to temperature, but Idk how plausible that is?

Would appreciate further input from you though.

 

Usally uh sorry bout the brain thing first off.ok you need replacements you can try to take apart and repack the needle bearings in the end caps but those are probably toast by now anyways.
1st, there are four bolts that hold the ujoint in place too the rear end. un do those. then slide the drive shaft towards the front it will slide up in the tranny too do this.
2nd place a rag at the end of tranny too catch fluid not a lot will come out but some will.
3rd nremove drive shaft and find a vise.
4th if your gonna have a mechanic work on it your looking at 2hrs labor shouldn't be more than that. i'm not at liberty too go on but there are sites here that will help.
Also the replacements usually have a grease fitting for you too lube in the future. I dunno why they don't come stock.