I had my rear differential fluid changed and it had metal shavings in it. ( they showed me and it was a lot) I can feel the car struggling a little off complete stops and then take offs. The fluid change made a heck of a difference too. Do i need to replace the gears?

 

If the mechanic didn't call it out then I would generally say no. But they did. And you said there were a LOT of shavings. I would start looking for a replacement.

Paul

 

Is it the entire pumpkin or just the gears inside? Not sure what to purchase.

 

DAVEB1980,
After the fluid change is the differential currently making noise? If not, I'd continue to drive it until it does or some other symptom from the differential starts (excessive drag?). Our cars have robust open differentials that typically last the life of car. How many miles does your car have on it? I always find dark gray metal shaving on the drain magnetic drain plugs when I change the fluid. It's shinny metal shavings that are a indication of a more immediate problem that may need attention soon. But even then, I'd continue to monitor until other symptoms showed up. If there were chunks of metal (gear teeth)particles on the drain plug the size 1/16 inch diameter or bigger, then I'd start looking for a replacement.
Barry

 

Car has 79,000 miles runs really well. The shaving where gunked over in grease but they were big enough to see. The car had never had a differential fluid change before. I think I need to start looking for gears!

 

Do you have any diff whine? You should hear it if it's failing. I would do maybe 10000 diff oil change to try to clear it out, can you add a magnetic drain plug?

 

No whine at all. I like the magnetic drain plug idea. Any idea where to find one?

 

the plug is already magnetic. The first gear oil change you should see lots of tiny metal shaving on that plug. To me It's normal. Dont bother to change or worry. Just change the fluid every 30k-60k miles from now on, if you dont mind taking care of the car

 

The Lexus User Manual for my 06 Lexus GS300 RWD shows that the car requires Full Synthetic Hypoid Gear Oil with API GL-5 and SAE 80W-90 .
It also gives a healthy dose of warning to only use genuine Toyota differential oil. And aftermarket oil, even with the exact oil rating, can cause damage to the differential and reduce gas mileage. See attached image.



Wondering how much of that is marketing since Toyota gear oil is $81/qt vs. aftermarket gear oil is less than $20/qt.

I noticed on this post that almost everyone used aftermarket gear oils. Did anyone experience lower gas mileage after using an aftermarket oil?

 

I changed the gear oil just once in the life of the car which is at 103k miles now. Could have been at 70 k miles or so. Used Mobil 1 synthetic IIRC with rating either exactly at or very close to the spec. Rear diff is just fine.