cdrdr 3 Posted October 12, 2022 I have a 2004 Honda rancher a/t with the hondamatic transmission, clutch starts slipping when climbing steep hills or at high rpm, two Honda shops immediately said “needs new transmission” so I got a second opinion by this amazing community and someone recommended I test the oil pressure, at idle it is 20-25 psi (normal) at almost full throttle it maxes out at 60-65 psi (should be above 85psi) the guy who recommended I test the oil pressure said he recommends changing the seals in the oil pump and rebuilding it. What do y’all think? Not that I don’t trust him just asking for opinions! Share this post Link to post Share on other sites
shadetree 5,969 Posted October 12, 2022 37 minutes ago, cdrdr said: I have a 2004 Honda rancher a/t with the hondamatic transmission, clutch starts slipping when climbing steep hills or at high rpm, two Honda shops immediately said “needs new transmission” so I got a second opinion by this amazing community and someone recommended I test the oil pressure, at idle it is 20-25 psi (normal) at almost full throttle it maxes out at 60-65 psi (should be above 85psi) the guy who recommended I test the oil pressure said he recommends changing the seals in the oil pump and rebuilding it. What do y’all think? Not that I don’t trust him just asking for opinions! if the oil pump seals can be replaced ?, then yes...rebuild it. Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 15 minutes ago, shadetree said: if the oil pump seals can be replaced ?, then yes...rebuild it. If I can only buy a replacement and replace the whole unit would you still recommend that course of action or do you see any other causes that could make these symptoms happen Share this post Link to post Share on other sites
toodeep 1,759 Posted October 12, 2022 Are you getting a grinding noise when it's giving problems? There are no seals in the oil pump (the Rincon did have o ring issues but that's a different set up) so that shouldn't be an issue. It is possible an internal o ring went bad and bleeding off oil presure but very slim. If your oil level is being checked correctly and your using quality oil, the 2 honda shops are probably correct. NOW... If there is no grinding noise (with that oil pressure test there should be) then it might just be the centrifugal clutch slipping but with the info given I hate to say I don't think that is it. Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 7 minutes ago, toodeep said: Are you getting a grinding noise when it's giving problems? There are no seals in the oil pump (the Rincon did have o ring issues but that's a different set up) so that shouldn't be an issue. It is possible an internal o ring went bad and bleeding off oil presure but very slim. If your oil level is being checked correctly and your using quality oil, the 2 honda shops are probably correct. NOW... If there is no grinding noise (with that oil pressure test there should be) then it might just be the centrifugal clutch slipping but with the info given I hate to say I don't think that is it. Yeah it grinds when the clutch slips at high rpm or under heavy load but not other times by what I can tell, it may be the transmission it’s just odd that a lot of people who take apart these transmissions “find no visual information stating what could be wrong” so I was trying to cover my bases before throwing down 2500+$ Share this post Link to post Share on other sites
toodeep 1,759 Posted October 12, 2022 The transmission is a hydro pump unit more than a transmission. Usually it's either bad bearings or scored pistons that cause the issue. Our problem is they are not serviceable. A few guys spent time sourcing parts close enough and with some machine work rebuilt them (the rubicon that shares the same style) but if there's internal damage they are junk. I bought a 400FA a few years ago with a bad transmission (same as yours) and got lucky and found a complete motor with only 600 miles on it. It did go through a fire but what I needed was all good. $450 to my door, swapped out a few case covers and that machine was up and going again. It took me about a year to stumble across that good motor though. In my area the market prices seem to be going back down so price wise it might be more feasible to update and part your machine out or search for a wrecked machine you can buy cheap for parts. Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 When you say an entire motor, can the transmission alone not be replaced or does the entire motor transmission combo have to be done at the same time Share this post Link to post Share on other sites
toodeep 1,759 Posted October 12, 2022 Just the transmission can be replaced. On mine since I found a complete motor I choose to use the motor with 600 miles on it vs the one with 14,000 miles on it. 1 Share this post Link to post Share on other sites
jeepwm69 7,719 Posted October 12, 2022 Looks like a few orings on the pump, and should be easy enough to check them before you drop $$$ on a new Hondamatic. #10 and #9 in the schematic. That said, probably the ones Toodeep is referring to that are "not likely" as they are not internal to the pump. https://www.partzilla.com/catalog/honda/atv/2007/trx400fa-a-fourtrax-rancher-at/oil-pump 1 Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 Thank y’all, I’ll keep the post updated in coming weeks after I get o rings replaced Share this post Link to post Share on other sites
ATC4ever 1,084 Posted October 12, 2022 When mine did the 'grind' noise it was low on oil as i was not checking it right. My experience, not saying yours 'isnt' bad, but mine did the same thing a couple times in close to 8 years after i had changed the oil, it was low only. How many miles/kms on it? Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 44 minutes ago, ATC4ever said: When mine did the 'grind' noise it was low on oil as i was not checking it right. My experience, not saying yours 'isnt' bad, but mine did the same thing a couple times in close to 8 years after i had changed the oil, it was low only. How many miles/kms on it? Only 450 hours 2500-3k miles and I checked the oil and it’s 100% full, but like I said I did the pressure test last Night and the idle pressure it good but high rpm pressure is low, which is why I thought it may be the oil pump not pumping enough oil at high rpm to keep the clutch and transmission lubricated enough. But like I said I’m only grasping at straws, the guy who rebuilds the transmissions said in all his experience, he’s taken them apart and they never look like anything is wrong, unlike the rubicons when you open them up something is broken causing the issues. Share this post Link to post Share on other sites
toodeep 1,759 Posted October 12, 2022 I had a few minutes so I ran out and grabbed my junk one and tore it down. Quite a few piston pins broke off in it and one of the cages that make them operate. Gives you an idea of what could happen anyway. Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 3 minutes ago, toodeep said: I had a few minutes so I ran out and grabbed my junk one and tore it down. Quite a few piston pins broke off in it and one of the cages that make them operate. Gives you an idea of what could happen anyway. Any leads on a part out machine I could salvage a transmission out of? Share this post Link to post Share on other sites
toodeep 1,759 Posted October 12, 2022 I don't have any but I haven't been looking either. Share this post Link to post Share on other sites
cdrdr 3 Posted October 12, 2022 4 minutes ago, toodeep said: I don't have any but I haven't been looking either. Ok sir thanks for your input, keep me in the loop Share this post Link to post Share on other sites