woodsman1 2 Posted December 1, 2020 (edited) I have looked a numerous posts for Rancher shifting issues but I believe I have a different problem. When shifting into reverse it seems that it does not go into gear, however, if I rev it up, it will actually take hold and go (acts like a stall converter). It does this in 1st also but not nearly as bad as reverse. Once in gear it performs as it should with no slipping, even with a load or resistance such as climbing steep hills. My first thought was a clutch issue but if that were the case, why doesn't it slip under load. Anyone else experience this and how was it corrected? Edited December 1, 2020 by woodsman1 Share this post Link to post Share on other sites
jeepwm69 7,783 Posted December 1, 2020 Welcome aboard. The wife's 09 DCT Rancher does the same. I figured the centrifugal clutch was slipping a bit so I ordered new clutches for it, but it hasn't gotten worse, so might just be the nature of the design. Share this post Link to post Share on other sites
Melatv 797 Posted December 1, 2020 (edited) Hi: Big Welcome Here === What are you using for engine oil? -- Is the oil at the right level? -- Are you in a cold place? Edited December 1, 2020 by Melatv Share this post Link to post Share on other sites
woodsman1 2 Posted December 1, 2020 (edited) Thanks for the Welcomes! Using Honda Oil. So here is what I believe started the issue. When I pulled the drain plug to change oil the threads came out with plug. I went to a local auto parts store and bought a self threading oversize drain plug which seemed to work fine but it was a 1/4" longer. At that time I also filled with Valvoline ATV oil. I ran it about 5 miles and the issue began. I pulled the drain plug and cut it down to the correct length thinking it may have been restricting oil flow. At that time I also filled with the recommended Honda 10W-30. It was ok for about 5 miles and then began doing the same thing. It is really is bad in reverse as you have to build good RPMs before it engages. However, even under load, it does not slip once engaged. It does however seem to fall out of gear when backing off throttle until RPMs are raised again. ATV only has 1200 miles on it . Edited December 1, 2020 by woodsman1 added wording Share this post Link to post Share on other sites
jeepwm69 7,783 Posted December 1, 2020 Is it completely full? These things are very picky about oil level. 1 Share this post Link to post Share on other sites
woodsman1 2 Posted December 1, 2020 Oil level is correct. Share this post Link to post Share on other sites
retro 4,074 Posted December 2, 2020 Hi woodsman1, welcome to ATV Honda! Does it get worse after the motor is warmed compared to a cold startup? In other words, is it working OK when it's stone cold? Share this post Link to post Share on other sites
woodsman1 2 Posted December 2, 2020 Yes, ok at start up. Share this post Link to post Share on other sites
retro 4,074 Posted December 2, 2020 Okie dokie! Now we know that the issue is a hydraulic one! The FA/DCT models require high motor oil pressure (with sufficient volume) to operate. The fact that clutch operation is satisfactory while the motor oil is cold, but begins to fail & worsen as the motor oil warms indicates that there is either an internal oil leak, a clogged oil pickup strainer screen, or a worn out oil pump. Cold motor oil has a thicker viscosity (viscosity correlates to temperature) than warm oil -- the thick viscosity of cold oil is more resistant to flow which results in a much higher oil pressure at the oil pump output port than warm oil produces. This explains why the clutches work when the motor is cold-started, but fail as the motor oil warms up. We have a clue as to what have most likely happened too. The oil drain plug threads stripped out.... that was repaired by screwing in an oversize drain plug that cut new threads in the aluminum case. But that repair was done without disassembling the motor to clean out all of the loose metal pieces which both drain plugs freed from the case. So many/most of those loose metal fragments in the oil sump went past the strainer screen and went through the oil pump. Then clutch engagement began to fail as the motor oil warmed, oil viscosity thinned & oil pressure/pumped oil volume dropped below what is required for proper clutch operation. I believe that the oil pressure bypass relief valve is stuck which causes an internal oiling system leak. It has hung partially open due to loose metal particles jamming the movement of the valve in its bore. You should check the oil pressure with a gauge before taking the front cover off of the motor to clean & fix it though. Don't trust my words 'cause I'm only willing to bet someone else's paycheck that I have diagnosed the problem correctly. 😀 The oil pump is upsteam from the oil filter (where metal fragments may become trapped) so I'm thinking that the pressure relief valve is stuck inside the pump. But there is an additional orifice relief valve in the front cover, downstream from the oil filter, that controls/directs oil pressure & volume to/between the two DCT clutches. So its possible that orifice relief valve may be hung rather than the one inside the oil pump... or both valves could be stuck. You can check that orifice valve operation using an oil pressure gauge as well. You can also take that orifice valve apart to clean it without removing the front cover from the motor. You can probably find some small brass fittings to adapt a standard automotive manual oil pressure gauge to use for pressure testing at any well-stocked mom&pop hardware store. I'll post some stuff from the Honda Rancher 420 service manual that might help ya diagnose and repair your TRX420FA2 (and maybe help others that find this thread in the future) below. Let us know what you find out so we might learn too! :-) Keep us posted as you work if you can. 3 Share this post Link to post Share on other sites
jeepwm69 7,783 Posted December 2, 2020 Excellent as usual Retro. Hopefully this will get him on the right path. 2 Share this post Link to post Share on other sites
woodsman1 2 Posted December 2, 2020 Thanks Retro for the informative response, it is greatly appreciated. May be a couple weeks before I have the time to get into it, but I will update the post when I do. Thanks again! 2 Share this post Link to post Share on other sites
retro 4,074 Posted December 3, 2020 Thank you for choosing to hang out with us woodsman1. I'm looking forward to learning from you! Share this post Link to post Share on other sites
woodsman1 2 Posted January 14, 2021 I finally located the required 8MX1.25 brass fitting to adapt to an oil pressure gauge and was able to run the pressure check at oil gallery bolt 1 on rt. side of engine. With a warm engine, at idle I had 74 psi and 120 psi at approximately 5000 rpm (I do not have a tach but was under the rev limiter). So, I believe this indicates that the oil pressure release valve is stuck. Retro, would you agree with that? Share this post Link to post Share on other sites
retro 4,074 Posted January 14, 2021 Yup! The line pressure is way too high. Its suppose to measure about 74 PSI while at 5000 RPMs. So ya probably have an oil pump bypass valve stuck, or possibly debris blocking the exit galley somewhere between the oil pump and the oil filter. I'm interested in what ya learn in there. Share this post Link to post Share on other sites
retro 4,074 Posted January 14, 2021 Here is the troubleshooting chart and related oiling stuff for y'all that are following along: Share this post Link to post Share on other sites
woodsman1 2 Posted April 7, 2021 Progress report: I finally had the opportunity to remove the motor and took it to a friend who has a clean shop to remove the front cover and also replace the front cover spacer case. We discovered the oil relief valve was stuck with 2 small particles of aluminum. Oil pump and everything else internal checked out ok. Cleaned everything up and reassembled. After reassembly and sitting on the bench, my friend looked at the front case and said you know, we should have pulled the orifice relief valve and checked it before reassembly. Sure enough it is stuck and we are unable to remove it. So, has anyone had experience with removing a stuck orifice valve? If we remove the front cover once again, can we access the valve from the inside? I really cannot see anyway to grab it and pull it out. Any help would be appreciated. . Share this post Link to post Share on other sites
jeepwm69 7,783 Posted April 7, 2021 Great info on what you found. Thank you for sharing! It's been 5-6 years since I rebuilt the wife's DCT. I honestly don't remember on the orifice. Sorry I can't be of more help there. Share this post Link to post Share on other sites
retro 4,074 Posted April 8, 2021 I don't have any experience with popping a stuck orifice valve plunger loose so the only strategy that I can think of is heat + hydraulic pressure. I would try to figure out a way to adapt a grease gun to the oil galley then heat the cover up in an oven slowly to 200-250 degrees F before pumping grease against the stuck plunger. @toodeep, do you have any ideas? 2 Share this post Link to post Share on other sites
Melatv 797 Posted April 8, 2021 Have you tried WD40 with a little bit heat and tapping lightly on the spot where it's stuck? 2 Share this post Link to post Share on other sites
toodeep 1,760 Posted April 9, 2021 I've never had the issue so no first hand knowledge here. The front cover is just hondabond though so I would pull it since it's still on the bench and try air pressure or anything to free it. If using air pressure expect a flying part so be prepared for catching that. 1 Share this post Link to post Share on other sites