Anyone have issues with the 51R battery leaking? I made the switch to the 51R battery 3 years ago. Recently my '09 was having trouble starting and when I pulled the battery I noticed some corrosion inside the engine. It looks like the airbox has been rubbing the the side of the battery, causing a hole and some battery acid leaked out. Anyone else have this problem?

 

Not us, but you easily COULD have that issue, because the larger battery WILL rub on the airbox if you don't do anything about it.

When we installed the 51R, I ground off some of the airbox flange because it was rubbing on the battery. Now we have a ~3mm gap.

Looks as if you totally removed the tray under the battery as well. *tsk* We fitted a junkyard tray from a Honda that used a 51R (CR-V I think).

 

Yeah I think I threw that tray out because it didn't fit the 51R battery. But I'll try the CR-V tray method. Thanks!

 

That won't stop the rubbing, just so you know.

If your replacement battery were overfilled, or the electrolyte had expanded during times of extra draw (mostly during the summer), battery acid would leak out and cause the corrosion in your pictures.

So now, you need to sand & paint the damaged metal in your pictures. For even more protection, apply truck bed liner on top of the last layer of paint. That way you won't need to find another battery tray.