From the symptoms I suspect it is the rear differential.
There is a technical bulletin on it.
Get it checked at Honda.
Tech Bulliten# 07-024, issued 04/20/2007 MOAN or GROAN from rear differential!
Probable cause, CONTAMINATION in rear differential oil!Corrective action, Replace fluid with new fluid and Burnish clutches.(Drive short while making tight turns)
Dual pump fluid Part # 08200-9002, H/C 6512644 1.3 qurts per vehicle per replacement. (2.6Quarts Total)
In Warranty, normal warranty applies!
Thursday, June 19th, 2008 AT 10:55 AM