algdunn 0 Posted November 15, 2021 hello, the shifter shaft on my 500 trx is broke off outside the engine approx 1 inch. (not much on the internet) Does this job require an engine removal? Share this post Link to post Share on other sites
jeepwm69 7,719 Posted November 15, 2021 Welcome aboard. You MIGHT be able to do it with the engine in the frame, but it will be very tight working conditions and will require a lot of finagling. You'll have to pull the rear swingarm and airbox to be able to get to the rear of the engine. You'll have to remove the rear engine cover, and undo one 10mm bolt. Once that bolt is out, what remains of the shift shaft can be pulled out, and a new shaft put into place. The tricky part will be getting the new shaft perfectly aligned with the arm. without having that arm fall out or into the engine. (#17 in this schematic). https://www.partzilla.com/catalog/honda/atv/2008/trx500fm-a-fourtrax-foreman-4x4/gearshift-drum I THINK that the spindle/shaft (18) will keep the arm from falling into the engine, but I'm not positive of that. The shift shaft will only go into that arm if perfectly aligned, and the splines are cut so that there are two alignment splines that must be lined up for the shaft to slide into the arm. You could possibly get a magnet to hold the arm in place while you slide the old shaft out, and then slide the new shaft in, but it will be tricky, and if it does fall into the engine....well, then you get to pull the engine and tear it down. The good news is, if you have to tear the engine down, it's a perfect time to ungrade your low gear set to the newer/stronger 09-11 gears. 1 Share this post Link to post Share on other sites
algdunn 0 Posted November 16, 2021 I didn't think I'd get that lucky. Funny thing is the engine was stripped down for tyranny overhaul and new pot and piston 18 months ago. I think it'll be going to the shop. I'll have to check but I'm pretty sure it had all the upgrades done then. I noticed it was really tough to shift at times( probably got worse) and causing to much strain on that shift shaft. Thanks for the info. Share this post Link to post Share on other sites
jeepwm69 7,719 Posted November 16, 2021 14 hours ago, algdunn said: I didn't think I'd get that lucky. Funny thing is the engine was stripped down for tyranny overhaul and new pot and piston 18 months ago. I think it'll be going to the shop. I'll have to check but I'm pretty sure it had all the upgrades done then. I noticed it was really tough to shift at times( probably got worse) and causing to much strain on that shift shaft. Thanks for the info. Probably needed a clutch adjustment. If you're at all handy with wrenches it's not too bad of a job if you can pay attention to details. Share this post Link to post Share on other sites
shadetree 5,969 Posted November 18, 2021 On 11/15/2021 at 10:58 AM, jeepwm69 said: Welcome aboard. You MIGHT be able to do it with the engine in the frame, but it will be very tight working conditions and will require a lot of finagling. You'll have to pull the rear swingarm and airbox to be able to get to the rear of the engine. You'll have to remove the rear engine cover, and undo one 10mm bolt. Once that bolt is out, what remains of the shift shaft can be pulled out, and a new shaft put into place. The tricky part will be getting the new shaft perfectly aligned with the arm. without having that arm fall out or into the engine. (#17 in this schematic). https://www.partzilla.com/catalog/honda/atv/2008/trx500fm-a-fourtrax-foreman-4x4/gearshift-drum I THINK that the spindle/shaft (18) will keep the arm from falling into the engine, but I'm not positive of that. The shift shaft will only go into that arm if perfectly aligned, and the splines are cut so that there are two alignment splines that must be lined up for the shaft to slide into the arm. You could possibly get a magnet to hold the arm in place while you slide the old shaft out, and then slide the new shaft in, but it will be tricky, and if it does fall into the engine....well, then you get to pull the engine and tear it down. The good news is, if you have to tear the engine down, it's a perfect time to ungrade your low gear set to the newer/stronger 09-11 gears. but, what about the thrust washers ?, once he pulls the shaft out, all the thrust washers will fall into the engine. as for even getting the shaft out without pulling and splitting the engine ?, i don't see how he will get around this. reason: the shift shaft slides into the rear engine cover, mates to the side shaft. on each end of the shifting shaft is a thrust washer, and both of these have to be placed/stacked. i don't see an easy way to change out this shaft without splitting engine. Share this post Link to post Share on other sites
jeepwm69 7,719 Posted November 18, 2021 1 hour ago, shadetree said: but, what about the thrust washers ?, once he pulls the shaft out, all the thrust washers will fall into the engine. as for even getting the shaft out without pulling and splitting the engine ?, i don't see how he will get around this. reason: the shift shaft slides into the rear engine cover, mates to the side shaft. on each end of the shifting shaft is a thrust washer, and both of these have to be placed/stacked. i don't see an easy way to change out this shaft without splitting engine. He’s talking about the shaft that the shifter actually goes on. Share this post Link to post Share on other sites
jeepwm69 7,719 Posted November 18, 2021 On 11/15/2021 at 9:28 AM, algdunn said: hello, the shifter shaft on my 500 trx is broke off outside the engine approx 1 inch. (not much on the internet) Does this job require an engine removal? Where are you located @algdunn Share this post Link to post Share on other sites