Destructo 12 Posted June 13, 2023 (edited) Hey all, so ive got a 2004 trx500 torn down, case split and am inspecting everything. It happened because of a strange whine i heard while descending hills that my other identical bike doesnt make, both bikes had different oil pressures so i figured id replace the oil pump while im in there. So , the hondamatic: it has a big of in and out play in the dark metal head part of it that sits and the front of the motor. when i rotate it it has a tiny tiny bit of a sound like marbles rolling around but i cant see any damage and it "appears" as if the sound comes from the little 'pins' moving up or down as they are rotated around the assembly. Does anybody have a video of what it should sound like when the hondamatic is rotated on a bench? should it be completely silent? It rotates smooth and all and while put together it ran fine, just wanted to ensure it doesnt break on me while out in the woods and for the price of a cheap oil pump and teaching the wife how to dismantle and reassemble the bike its worth it...supposing the hondamatic isnt about to die regardless. Any info is appreciated. Thanks! Edited June 14, 2023 by Destructo Share this post Link to post Share on other sites
jeepwm69 7,719 Posted June 14, 2023 15 hours ago, Destructo said: Hey all, so ive got a 2003 trx500 torn down, case split and am inspecting everything. It happened because of a strange whine i heard while descending hills that my other identical bike doesnt make, both bikes had different oil pressures so i figured id replace the oil pump while im in there. So , the hondamatic: it has a big of in and out play in the dark metal head part of it that sits and the front of the motor. when i rotate it it has a tiny tiny bit of a sound like marbles rolling around but i cant see any damage and it "appears" as if the sound comes from the little 'pins' moving up or down as they are rotated around the assembly. Does anybody have a video of what it should sound like when the hondamatic is rotated on a bench? should it be completely silent? It rotates smooth and all and while put together it ran fine, just wanted to ensure it doesnt break on me while out in the woods and for the price of a cheap oil pump and teaching the wife how to dismantle and reassemble the bike its worth it...supposing the hondamatic isnt about to die regardless. Any info is appreciated. Thanks! The 2012 I'm wrapping up spins quietly with no noise. That said, if yours turns smoothly it's probably ok. I'm not sure what year the updated oil pump went into production, so I'd ask Brian about that before you order a new oil pump. I'm PM"ing you his email address. Share this post Link to post Share on other sites
Destructo 12 Posted June 14, 2023 (edited) Heres a video showing its movement. Is this too much play? Does it seem okay to reinstall? received_1434019520470591.mp4 Edited June 14, 2023 by Destructo Share this post Link to post Share on other sites
jeepwm69 7,719 Posted June 14, 2023 I'd run that, but before I did, I'd ask Brian for his opinion. There are only two "experts" I know of on the Hondamatics. Brian is the OG, and a user named Harig on the old board knew them well too. I'm pretty sure Brian taught Harig the ropes. Anyhow, they both figured out how to rebuild the Hondamatics IF they weren't too far gone, and offered a rebuild service. Send that to Brian and ask him for his opinion. I have mine all the way back together now or I'd see how much in/out play mine had. Yours appears to spin smoothly, so that's definitely a good thing. Share this post Link to post Share on other sites
Destructo 12 Posted June 14, 2023 Thanks. I sent him an email with the video as an attachment. Any idea what the whining sound could be while slowing down or descending a hill? One way bearing? I already have a new oil pump so I'll probably install it into this one and use his ones factory pump in my 2003 when it's on the bench lol Share this post Link to post Share on other sites
jeepwm69 7,719 Posted June 15, 2023 19 hours ago, Destructo said: Thanks. I sent him an email with the video as an attachment. Any idea what the whining sound could be while slowing down or descending a hill? One way bearing? I already have a new oil pump so I'll probably install it into this one and use his ones factory pump in my 2003 when it's on the bench lol Every Rubicon I've been around is noisy when engine braking. Not sure if it's the Hondamatic or the one way, but it's normal. Most have a "whirring" sound when driving them. Louder on some than others. I think it's just the nature of the beast. Share this post Link to post Share on other sites
Destructo 12 Posted June 17, 2023 Okay. I spoke with brian and he says this amount of play is normal. I'm gunna send it lol 1 Share this post Link to post Share on other sites
jeepwm69 7,719 Posted June 18, 2023 Good to know! Did you ask him about the year of the change in the oil pump? Share this post Link to post Share on other sites
Destructo 12 Posted June 18, 2023 No but I read a previous post he was involved with where it was stated that 2004 was the upgraded pump, which i have a brand new one anyways so this ones factory pump goes to my 2003 lol 1 Share this post Link to post Share on other sites
jeepwm69 7,719 Posted June 20, 2023 I got my 2012 engine back in the frame this weekend. It fired right up, but immediately threw an error code 6/angle sensor. When I tried to initialize the system I could hear the shift motor click/ not rotate, and upon inspection it appears that my swash plate is jammed up now. Not sure what I did, but looks like I'm going to have to pull it and take it back apart. It spun freely in both directions when I had the cases split, so who knows what I did to bind it up. Lesson learned! Check the swash plate gear and make sure it spins with each step as you reassemble a Hondamatic engine! Share this post Link to post Share on other sites