I have a 2004 rancher 400 automatic/esp and while i was up hunting i rode it all day for four days straight without an issue, left it overnight one night and then hopped on it the next day and immediately it started giving me problems. When in drive in either auto or esp it seems as if it is stuck in a really high gear right from the start, esp won't let me shift gears either it just flashes --. Also, when in neutral if i rev it up a bit i can hear a deep sound that sounds like a spinning part is being resisted against, kind of sounds like an electric drill, however it idles without a problem. Any help would be greatly appreciated, thanks.

 

I had a whirling sound and clutch slippage in my 05 rincon 650 because I had synthetic oil in it- I put the honda oil in it and bingo! No more whirling sound and no more clutch slippage. Just a thought-

 

I changed the engine oil back in the summer and put the honda GN4 (recommended) oil in it so that shouldnt be an issue, thanks though!

 

It sounds like the transmission is stuck in limp mode. Is there any pause between flashes?

The 400AT is one that I don't have a manual for and I haven't messed with. Getting a service manual might be a good investment.

 

Synthetic oil will not hurt the 400 AT....

My oldest son drives an 04 400 AT and uses Shell Rotella 5W-40 synthetic in his and has had no issues what so ever!

Being it is an auto with ESP....look into the angle sensor and/or shift motor.

Like Jeffin said, invest in a manual and check for codes on the display.

As for clutch slipping with a synthetic......if you use "Energy Conserving" oil....that's a possibility.

 

I don't know about the 400 at- but even the mechanic at the honda dealer said I couldn't use the synthetic oil in my rincon 650. As soon as I replaced it with the honda oil, it stopped whirling and slipping- proof enough for me to not use synthetic again

The manual says nothing about synthetics- just to use honda oil.