My 08 TL never had any issues when I had it, my wifes 09 RDX with 50k miles has a cracked rear differential. I have never seen this before on any car, nevermind a fairly new one.

The crack is right below the drain plug

Anyone seen this before? Any idea how to fix it?
I could try to weld it, but it looks like Cast Iron which doesn't weld very well.

Appreciate the help

 

Weird, good that's its the housing, not the diff itself. It should be aluminium. don't quote me and I would figure it would be easier to fight Acura about covering it under warranty. 50k is not far enough to be out of you're drive train warranty.

 

You're a genius, looks like the powertrain warranty is 6 years, 70k miles

I am hoping this is not a sign of things to come

 

pics please!

 

^And some history of how it's been driven. Are you the only owner?

 

Here is the best picture I could get.

I am not the first owner, bought it with 24k from a Honda dealership. My wife isn't a terrible driver, this is certainly not an impact crack.

 

Sorry. Hard to see in that pic. Is it cracked? The plug may have been overtightened so far that the threads cracked. Or it may be loose. Get a bright flashlight and a paper towel. Wipe it clean and see if it failed from the inside or the outside. Like impact vs over tightening.

At any rate warranty may not cover it unless none of the above happened. Like if it just cracked from force while driving. Are you modded? You may have to push them to cover this, depending what it is and what caused it.

Good luck!

 

It is cracked 1/3 of the way down the case, starting from the drain hole.
I replaced the crush washer and the plug was not overly tight to begin with. Didn't fix the issue, it is leaking directly from the crack.

It is not modded, wife hasn't even washed it in a year lol.

I have had good luck with Acura honoring their warranties, nothing like the Audi I have now, which is a POS and Audi won't fix anything under their warranty...

 

Did you have the rear diff service at Acura since you owned the RDX? Maybe you can get them to pay for it if you can prove they service the vehicle.

 

No, never had anything done with the differentials. I honestly don't know what would cause this, other than an imperfection in the case.

 

There is no sign of an impact on the bottom of the diff. That is definitely cracked from overtightening.

A shop should be able to drain it and weld it. If you are mech-inclined, you may even be able to JB-Weld it.

But push all the way for the warranty first.

 

So Acura told me no way they were fixing it under warranty since the bolt has been removed.
How do they tell it has been removed?

It is going to be $4,400 to replace the entire differential including gears because dealerships don't replace what is broken, they replace as much as they can possible get away with.

I am obviously disgusted with Acura right now and thinking about trading it in for a Toyota instead of fixing it.
There is no way I am putting $5k into a car with 50k miles

 

this could happen in extremely cold climates where the iron bolts expand and contract from -30'c to near 60-80'c when car gets hot. specially if it has been overtightened. thats why you should inspect the car inch by inch when you buy one.

 

I live in Boston, not the arctic. I have talked to 2 other dealers that say they have never, ever seen this before.
I don't understand how it happened all of a sudden

 

We could help if you provide more info.

1)Wipe the crack clean and use a flashlight to help get a pic with close up detail of the crack.
2) check your maint records and see when the previous diff service was done. If you have documentation on the diff service go back to the shop with proof of service and ask them what happened.

Cause is what can help define if it can be covered by warranty. Until you post a clear pic cause will remain unclear.