Rd400 wont shift gear

rd400greenhorn · May 31, 2021, 11:52:24 AM

So, no original drain plug.
Took the engine apart. Wierd - there was this piece of Bent metal sitting behind the oil cover?
Besides that everything looked fine No metal shawings or Any thing.

I removed the shift drum and compared it to Extra spare parts rd400.
Is it the right drum? They are pretty different...
The one i removed from the rebuild engine is the one on the left!

rodneya · May 31, 2021, 01:12:26 PM

cant tell the size of the mangled washer, but it could be from behind the circlip that holds the tach drive gear on (plastic gear you mentioned came off)

1976RD400C · May 31, 2021, 01:18:33 PM

FYI You can assemble the trans and finger tighten the clutch to hold everything in place in just the lower case and shift away and check everything before installing the top case piece on.

rd400greenhorn · May 31, 2021, 01:19:55 PM

Thats a good tip, Thanks :)

rd400greenhorn · May 31, 2021, 01:26:04 PM

Ahhh yes i believe your right. There is a washer behind the circlip. Awsome will find replacement tomorrow

rd400greenhorn · May 31, 2021, 01:49:17 PM

I actually suspect that maybe the shift drum i put in the engine is a Rd350 ac model? When dinding pictures on ebay they look similar with the size of holes

rodneya · May 31, 2021, 02:35:27 PM

Pretty sure there was an old thread that mentioned the 350 drum will work with 400 trans

Jspooner · May 31, 2021, 02:56:31 PM

Quote from: rodneya on May 31, 2021, 02:35:27 PM
Pretty sure there was an old thread that mentioned the 350 drum will work with 400 trans

Yes it works.

rd400greenhorn · May 31, 2021, 03:27:17 PM

Ah okay. Damn... Hmm.. Not sure what i can be then but Will try tomorrow with a different drum and dry run some shifting before doing anything Else

rodneya · May 31, 2021, 03:49:53 PM

Just remember that you will have to turn the sprocket a little by hand while shifting when you test or it will not shift.

rd400greenhorn · June 01, 2021, 09:16:50 AM

Allright. Been at it all day not sure what to think. I have put transmission in and shifted through the gears, but how easy should it be, being and old bike? I am shifting just lower engine case with Nothing but gears in the casing.

rd400greenhorn · June 01, 2021, 10:19:31 AM

Okay, gears are not working as they should
No were near shifting consistent just crap.
I have narrowed it down to believe Its the forks and or the axles they run on and the pins that run on the drum grooves.
Seems like those pins would benefit from having springs behind Them so they follow the grove 100 procent, Its as if they have a tendency to get stuck... No real damage to the drum either..

rodneya · June 01, 2021, 12:39:27 PM

What do your forks look like? Is there wear on the outsides of the points?

rd400greenhorn · June 01, 2021, 01:21:54 PM

Only pictures i got now. I have several forks but these for one

1976RD400C · June 01, 2021, 02:17:43 PM

Does the shift drum rotate for every shift and detent itself without the shift forks engaged to it?

News:

Rd400 wont shift gear