On any type of road (flat, incline, decline) when I hit 45 mph, the transmission seems to hesitate about which gear to pick. You can hear a rumbling sound (not loud) when this is occurring. Furthermore, I notice that the RPMs fluctuate up and down by about 200-300. I have brought the vehicle to several mechanics. One mechanic suggests that it’s the u-joint since it has a small flat spot. Another mechanic thinks a software upgrade is needed. The trans was recently flushed and the issue still persists. I tried looking up any service bulletins and did come across SB 06-062, which addresses a 4th gear issue on 2006 Ridgelines, but not sure if the issue I’m dealing with has anything to do with software, plus, I did not want to pay to see the details of 06-062.
This could open a can of worms.
Was the pan dropped and cleaned out? If not the flush could have stirred up debris and circulated through the trans.
Was the filter (if it has one) replaced?
Was it re-filled Honda specified fluid? Not some universal stuff with additives?
Excellent ideas above. OP might consider these ideas too.
Does this car have a lock-up torque converter? If so, besides the above, that would be my first suspect. In fact there may not be anything wrong, that is what LU converters do to some extent anyway. Drivers can start to notice this at some point, when it has been doing it all the while, just not ever noticed. (I had a VW Rabbit one time, and one day I noticed a faint high pitched whining noise only on heavy accel. It turned out it was just the fuel injectors doing their thing, and they had always been making that noise. I just never noticed it before.)
Your local public library may have an ALL Data subscription. If so, you could probably see the TSB’s All Data has in their database for this car.
U joint has a “flat spot”? Not sure what that means. Usually u-joints are diagnosed by manually twisting the driveline with your hands, looking for play in the joint. Any noticeable play, the u-joint is bad. I suppose there are other failure modes though for u-joints. It might be worthwhile to rule out the u-joint idea by simply replacing it. U-joint replacement is usually not overly expensive.
You can call the dealer and ask what was done. The software version should be 2.005.008 or later.
06-062
July 23, 2011
Applies To: 2006 Ridgeline - ALL
2007 Ridgeline - From VIN 2HJYK1…7H500001 thru 2HJYK1…7H513705
Transmission Intermittently Does Not Upshift to 4th Gear
(Supersedes 06-062, dated September 12, 2006, to update the information marked by the black bars)
REVISION SUMMARY
BACKGROUND
After the kick-down/passing gear is engaged at highway speeds, the transmission sometimes does not upshift to 4th gear for an extended period of time.
CORRECTIVE ACTION
Use the HDS with software version 2.005.008 (or later) to update the PCM PGM-FI software.
SOFTWARE
WARRANTY CLAIM INFORMATION
REPAIR PROCEDURE
Use the HDS with software version 2.005.008 or later to update the PCM PGM-FI software (refer to Service Bulletin 01-023, Updating the Control Units/ Modules).