afx588

So in the past two week or so, I've been hearing this faint whirring sound only at high speeds (60-70mph). When I first heard the noise, I asked my mechanic about the noise while getting an oil change. He took it for a drive and said that it's probably the wheel bearings on the way out. He does the tug test, but the wheels had no play. Being one of those old school guys, he said that bring it back when the noise gets worse.

So last week I was driving and I started noticing that the sound got much louder, and become very evident across all speeds. Since I moved really far away, I went to another mechanic, who also thought it was the wheel bearing. However, when he took off the hub assembly, he noticed that they were fine. Upon inspecting the diff fluid, he found a LOT of metal shavings and concluded that the diff is probably gone.

I took it to the dealer this morning for a second opinion. They actually disassembled the diff and confirmed that it's broken. Being freshly out of warranty (71K miles)....I'm hit with a huge repair bill. I'm trying to see if Lexus would be able to cover it anyways, but won't know until Thursday. Seriously...WTF?!?! I don't drive aggressively or thrash on the car at all.

Has this happened to any other members? The dealer said that they've never seen this happen before.

SCWB

In normal use, rear diff doesn't break easily. If you drift your car, race ti or spin the wheels frequently then that would be another story. Other possible causes are the wrong type of gear oil is used, leak diff case or neglected rear diff oil change.

Are you the first owner?

Lestrade

That's unfortunate, man. Before you shell out to have the dealership install a brand new one, I would see if you can find a front-end collision at a local scrap yard and see how much the diff from that would be. A quick ebay search comes up with ~$500 + shipping (you may also want to do new bushings). I haven't done a diff on a Lexus but I figure it should only take a few hours with a lift and the right tools, so an independent mechanic would probably only charge a few hundred dollars for labor. Bound to be much less than the dealership.

ISFPOWER

iTrader: (20)

they disassembled with your permission? did you see the actual diff apart yourself? something sounds fishy

topspeed55

Permission? Yeah he gave permission when he brought it in to have it inspected. I'm pretty sure they just opened the diff cover, don't make it sound like they removed the diff from the housing and took it all apart piece by piece.

Tell us when the diff fluid was changed last and what fluid was used?

ISFPOWER

iTrader: (20)

open diff breaking at 71k miles?

Gville350

iTrader: (10)

Okay, you've got three options :

1) Have the stealership replace the bad components in the current rear-end
2) Purchase a good, used rear-end that will just bolt-on (btw, I've read that some IS300 diffs work on the 250s)
3) Purchase an aftermarket LSD and pay to have it installed and the other components replaced

Good luck!

Jeff Lange

iTrader: (1)

Did they tell you what is actually damaged? Is it the ring and pinion or the differential unit itself? One of the pinion and/or side bearings?

Toyota differentials, and the one in the IS specifically don't seem to have many issues, but it is possible of course. Finding a used differential is probably the most cost effective repair method.

Jeff

whitebeast

iTrader: (5)

I'm really sure he doesn't need LSD according to his statement

f3nrir125

iTrader: (1)

I will be selling my open diff if that's what you need soon, because I'll be installing an lsd unit. PM me if you are interested.

bgqkeneg

I figure it should only take a few hours with a lift and the right tools

afx588

Thanks for the reply all. The dealership was supposed to tell me today if they will cover it under powertrain warranty, but I haven't heard back. Hopefully tomorrow. If they won't cover it in full, I'll at least see if they will cover partial, and see how that compares to the independent mechanic's quote. I'm in a bad situation because that's my only car, and I'm new in town and need to have it fixed asap.

I haven't been back to the dealership to see the actual broken diff, but over the phone the SA told me that the car is not driveable right now because they took the diff apart to confirm that it was messed up. All I've seen from the independent mechanic is the fluid that was changed out, and there was A LOT of metal shavings. The mechanic thinks that the gear teeth is probably rounded out. I tend to agree and I think that probably something went wrong during the metallurgy / manufacturing process of one of the gears. Usually diffs are pretty robust, so this really caught me by surprise...

I don't think the owner's manual calls out an interval for changing differential fluid. I'm the second owner of the car and I don't think the diff fluid has been changed before. I'm pretty handy and I'm sure I can fix it myself, but unfortunately I don't have the time, space, or tools to do so.

Keppie

Sounds like you are in a tough spot.

Everything will work out.