Phil221

So... After about a year long wait, my dash was finally replaced last week and it looks awesome. Major props to Lexus for standing by their product! Now, here's the quick left turn... The dealership did a full inspection of my GX and the technician reported that I need a new rear differential. Quoted @ $2400... Mind you, I did not notice any symptoms or heard any odd noises up to this point so I was pretty surprised, if not confused, by that diagnosis.

I ended up taking it to my local mechanic, today, who I trust a lot. I had him perform both a front and rear diff fluid change. Diagnosis: The fluid in both diffs were clean and there was no sign of metal deterioration in the oil or on the magnetic drain plugs. He said that they're both operating normally and are in good shape. So, WTF am I missing? Did Lexus try to rob me or maybe my mechanic missed something? Also, at this point there are no noticeable symptoms, as far as I can tell.

BradTank

Yea, it sounds like they tried to take advantage of you. They call them stealerships for a reason. It's actually pretty common for them to recommend service you simply don't need, that's what those service advisors basically are: salesman. Usually though it's things like new brake pads, usually they don't try and convince you to replace an entire differential.

Phil221

I really didn't want to believe that's what the deal was but my thought is that you're right. That's absolutely crazy and I keep getting the survey emails from them too lol

IanB2

Follow up with the tech at the dealer and ask him why he is recommending this service, what prompted him to suggest this to you, what did he see/hear/feel that lead him to believe there was an issue. How did you walk away from that conversation with these questions?!? Nobody else is going to be able to tell you what he observed (if anything).

ALAN553

I don't see a diagnosis there, just a treatment...didn't you ask what was wrong and how they came to that conclusion while they were replacing a dashboard? Considering there were no symptoms....

Phil221

I asked the service manager and he told me that the technician heard grinding noise coming from the diff. This is why I was surprised since I never heard anything at all and my mechanic confirmed that yesterday, he didn't hear anything either.

chiph9

If the fluid is clean, it's not making noise, and the backlash seems ok (how much slack there is when you hold one wheel and spin the other), I wouldn't worry about it.

Chip H.

Phil221

Neither the dealer nor my mechanic checked the backlash, so I'm not sure about that one. But there's definitely no obvious noise and the fluid was 'very clean' according to the mechanic. How loud is a bad diff? Is it very obvious?

micah360

I work in the Marketing Department for a company who owns four different high-end dealerships. Service dollars are the majority of their revenue and the only way they stay in business.

chiph9

You'll notice it most when making sharp turns. Find an empty parking lot, roll the windows down, and make tight circles, both to the left and right. If you hear moaning or clicking [1], that's when you know.

Chip H.

[1] This could also be CV joints

Phil221

Thanks man! I'll try this out this afternoon