I have a honda foreman 450 and the motor is torn apart on my bench. I was thinking 5th gear was out of it or somthing. It would start bucking real bad in 5th gear. I cannot find a diagram that tells me which gears make 5th gear so i can take a closer look. If any body has had this problem please help me out.

 

You tore it apart, and you don't have a service manual?

 

I do but the diagram is to hard to read. It is hard to see which gears are which

 

I suggest you get a better diagram

 

Boy you guys are a lot of help geegss

 

With the engine laying on its back side crankcase, cylinder studs facing away from you, the crankshaft will be to the left of the gear assemblies. The mainshaft is to the right of the crankshaft, and the countershaft is to the right of the mainshaft. The final driveshaft is to the right of the countershaft. There is a gear on the final driveshaft, it mates to a gear on the back of the counter shaft. The gear next to the drive gear on the countershaft is 5th gear ( second gear from the back engine crankcase half ). 5th gear on the mainshaft is the gear next to the back crankcase half.
As far as problems, check the grooves in the shift drum for wear or dammage, the shift fork, the slider sleeve on the main shaft ( which is actually 3rd gear) for wear on the ends where it engages into the center of 5th gear. Check the bearings in the cases where these shafts enter.
Note, there is one copper washer in this tranny, and many other spacer washers that are beveled on one side and flat on the other and should not be installed backwards. Also make sure the countershaft 3rd gear is installed the right away around. It looks the same, but if installed flipped the unit may not shift past 3rd gear when assembled. Always bench test the transmission with the crankcase halfs bolted together before assembling any other components, in case it must be split again to fix a shifting problem.

The bucking you are experiencing could be as simple as the detent roller spring on the shift drum star wheel. I have found a few that are weak and will let the shift drum move a little to far, allowing the engaged gears to temporarily disengage, then when torque is releived temporarily, the detent roller spring will have enough tention to move the roller back into the center of the star wheel points. Sometimes the spring can be so weak it will allow the unit to jump into another gear totally.

whatever, if you need anymore help let me know.

----- Gimpster -----

 

hey thanks for the info man i will look at everything you said and see if i can find anything wrong

 

I will give you another heads-up.
Check your shifter shaft seal, and the rear drive seal ( where the driveshaft attatches to the rear of the engine )
These 2 seals have been the source of why I know so much about these trannys. People work these units into the ground around here, and when one of these seals fails, they end up starving the engine of oil, ruining the crankshafts, so to replace a crankshaft the cases have to be split, and many times the gears fall apart when seperating the halves.. LOL, I learned the hard way ....

----- Gimpster -----

 

Thanks again for the extra tips if you have anymore feel free to share 'em. I might be able to get this wonderful atv back together again???