FRONT DIFFERENTIAL PROBLEMS

So my front diff can only go bad by putting the truck into 4WD?

 

You drove the truck for 3 weeks roughly without problems..

1. call or go to the shop that did the work
2. speak to the mechanic directly and ask him/her what the actual problem was in the first place
3. try recalling back and think what did you do with the truck in the last 3 months
4. have a friend or someone not familiar drive the truck and don't tell them anything and see what they say. Not questioning your diagnosis of "diff noise" but sometimes we need another set of ears" to hear to verify what we are hearing.

try that and lets see what happens also pics of the front suspension, you have hundreds of eyes hear that can look at it..

good luck let us know how it turns out

 

check to make sure your cv shafts are almost straight at ride height. If your front diff is not dropped when you did the lift then cv angles are gonna be way off. Grinding noises could be your cv's and could also stretch your seals causing a leak. If you could post up pics of your front diff and your cv angles from the front it could help diagnose stuff.

 

It's the only time the diff and the front drive shaft turns.

 

Not necessarily, the axle shafts turn all the time.
They ride inside bearings in the front differential.
I’m not saying that this is your issue, but there are parts inside the differential that still turn.

Your driveshaft does NOT turn while in 2WD. (Or at least it shouldn’t)

 

They do but with zero load and unlike the rear they are supported by real ball bearings not the spider gears, ring and pinion do not turn. If you have ever blown a spider gear in an open diff just one you are not going anywhere same concept.

 

Alright i work at a dealer, we had a 2017 taco with a little more than a 3" lift and 35's come in for a possible bad front diff. Guess what he didnt do? Yup, the needle bearing. It broke apart and grenaded the front diff. When you get a new front diff, ask them to take pics of the needle bearing, its on the drivers side front where the cv axle goes into the diff. Since your shit sounds fucked, i would look into a regear to 4.56's to make it feel drive-able again.

 

thanks for the tip. I just got the entire front diff replaced so wouldn’t they change that needle bearing while doing the replacement ?

 

I hear it mostly while coasting at 40mph, but it sounds like a rotational rub thats why I assumed it could be a U-joint etc with the driveshaft up front but honestly I got no clue.

 

If you look closely it almost looks like there’s a grind spot on the front diff itself, you can see a fresh grinded silver spot. WTF!?

 

I wonder if there is something loose or flexing or moving and touching the diff and your hearing the vibration sound.....

 

Your inner CV joint boot is out of whack. I wonder if that could make audible noise. I’ve never run 1 like that so I don’t know.

 

What the hell could be loose though? I’m sweatin this bad

 

Out of whack how so?

 

You can't see that this is out of whack?

 

It makes the most noise when coasting at around 40 mph ?
If you turn hard to the left , then hard to the right as you are coasting at 40mph , does the sound change in pitch?
Could you post a video of the sound ?
Does it go away if you get on the gas above 40mph ?
Have you tried shutting the truck off in nuetral and coast above 40 mph ? is the sound there with the truck off ?
As mentioned above , I would bring it back to the shop and tell him the noise is back .

 

If you have a GoPro, try making a couple runs with it from 0-50 and pausing when it gets bad. Do like 2 runs on each side and then take a look at the videos and see if anything looks out of sorts and if not post them on here and let us take a look to see if anything looks off. I would be worried about the needle bearing because when they swapped your front diff, I'm sure it was swapped with a new OEM one that also has a needle bearing so it was good for a while and then the needle bearing went bad again, but that's just my guess from what has been seen so far.