how soon till Diff dies?

Hi. I have a rear diff that started making a wah-wah-wah.. at 60-65mph about three months ago. didn't know what it was till recently. I have a single piece drive shaft that necessitated shimming the axle 2 degrees which turns the pinion up and sloshes the oil back into the pumpkin. supposedly, jiffy pop changed the Diff oil about 20k ago. but when I inspected it this past weekend, it was very black and stunk. there was metal dust on the magnet and shavings (I think) in the oil. changed the oil and added an extra 1.5qts..
since doing that, the vibration wah-wahs have somewhat diminished as the gears are finally submerged in oil.
hopefully, this is the last of the excess wear, but given that it was driven with less than optimal oil for a few months, will the lifespan of the diff be reduced? or am I just stuck with a new noise?

 

You within warranty on your 2020? is it 5 yr, 60k or something like that? Might just bring it in to the dealer see what they might be able to do.

My OEM lasted me about 10 years... was still going strong. Put in new gears and they lasted about a year hahaha. Just put new ones in, hopefully they last a bit longer this time.

As for how long yours will last, I bet that's a total crap-shoot. Could fail tomorrow, or 10 years from now, or maybe never. And I highly doubt that 2 degrees makes any difference whatsoever to the life of your diff. The amount of oil actually in contact with the diff would be negligibly changed when sitting on flat ground, and once you start driving the oil is going to be tossed around everywhere lubing stuff, as it should.

 

supercharger. no warranty

 

Find a dealer that doesn't pop your hood before saying they'll do the work

 

Worth trying, a supercharger doesn’t mean your warranty is void straight off the bat.

 

I agree with your point but I genuinely feel it would be a waste of time.

 

Seeing as how replacing gears is expensive... Don't think it would be a waste of time unless it was a really REALLY long drive or something.

 

im just convinced it won't be covered by Toyota. ill call the service dept tomorrow and see what they have available

 

I think the most likely thing would be for them to say, sorry, I don't hear anything. Or that's standard/within spec. lol.

Good luck though! Let us know how it goes. I was just lucky when mine failed, it was in my driveway not a thousand miles from home on a trail.

 

theres another layer to this actually. if they don't cover it, ill likely get 4.88 gears, which I want to do anyway?
the noise is very noticeable from 60mph+. they're going to say its the single piece shaft though. which I can argue was silent for the majority of the time ive owned it.

 

Re-gear has been awesome. I like this plan. Use the noise as reason to just break down, bite the bullet, and get it done.

 

side note: Toyota warranty is 36k or 3 years. they wanted 185$ to diagnose the issue. I drove away. now searching for a nnj tranny shop that can diagnose it and will install gears if needed. ive called two and they have both said they don't like to use aftermarket gears as they are all noisy.

 

ECGS does the complete 3rd member and you can get them to do a set pinion instead of the crush sleeve that the supercharger maybe damaging on takeoff.
Are you running a procharger?
I call BS on aftermarket gears as my OEM self-destructed in Ouray and now Yukon set installed.
A one-piece driveshaft can produce a whining/ringing with new tighter gears at certain rpms.
Agree on dealer will not want to touch with the Woods driveshaft as when my rear was having problems the first thing they said was I have to put a Toyota driveshaft set back in to even begin - again called BS and took it to a driveline shop.

 

2° is not much at all. You’d see more oil slosh from accelerating alone. I’d be surprised if that had anything to do with it but I could be wrong. Perhaps the 2° angle tips the diff in a way to when they fill it, the diff gets less fluid. (If they’re using the fill till it drips out of fill hole method).

Did you drain the diff completely when you checked the fluid? You’d be able to measure how much you got out (or amount jiffy lube put in). If they didnt put in enough they might be the ones to cover your new rear end.

 

Took it to a transmission shop and the guy told me not to worry about it. Said what he could barely hear sounded nothing like a d diff. Thanks for the replies.

 

From my experience, a worn diff will howl especially when you back off the gas and you're coasting. Usually pretty quiet on acceleration and cruising but it will wake up on decel and turn into a werediff.

 

This has been my experience also. I drove mine until the spider gears exploded… the replacement diff lasted 10 years until this noise started again.