Author Topic: Assembling transmission and I cannot get it to shift (Read 11377 times)

Mike Grant · « **on:** January 17, 2015, 12:11:09 PM »

Hey guys.....finally started to tackle my engine rebuild this weekend and I have run into a problem that is stopping me dead in my tracks. I installed new bearings in the transmission + cranks bearings this morning and have moved onto assembling the transmission. I have the transmission completely assembled in the right case half along with the external parts on the other side (shift star + detent)

The input / output shafts turn smooth but cannot get the shift mechanism to work by using the shift shaft and shifter (need more hands to hold the engine secure which I don't have any at the moments. I also turning the shift drum with Vice grips which I electrical taped the hell out of the vice grips jaws to avoid damaging the bushing surface......didn't work either

How the hell are you supposed to run this thing through the gears prior to assembling to make sure everything works ?

DoldGuy · « **Reply #1 on:** January 17, 2015, 12:23:39 PM »

Mike,

I assemble both case halves together, and then will turn the output shaft while shifting thru the gears to confirm I have all gears....

Hope this helps,

DoldGuy

Edit:

With your current setup if you remove the shift fork pins can you move yhe shift drum?

Mike Grant · « **Reply #2 on:** January 17, 2015, 12:34:02 PM »

Yes If I remove the shift fork locater pins I can turn the shift drum

DoldGuy · « **Reply #3 on:** January 17, 2015, 02:37:52 PM »

Can you spin both the input / output shafts with the pins out & the shift forks riding in the slots? If you are sure you have the forks in their proper spots, I would assemble both case halves together & check the shifting by spinning the output shaft.

DoldGuy

Mike Grant · « **Reply #4 on:** January 17, 2015, 03:42:11 PM »

Yep I can spin both shafts and there is no binding or any other problems. I took everything apart and quadruple checked all shift forks are correct against the manual and checked both gear clusters that all washers/gears are in the proper position. Everything is 100% correct according to the manual. Biggest problem I have right now is I don't have shifter to attach to the shift shaft so I was trying other methods to make sure this thing was going to shift before it went back together

DoldGuy · « **Reply #5 on:** January 17, 2015, 03:49:20 PM »

I'd put it together...

Mike Grant · « **Reply #6 on:** January 18, 2015, 06:28:44 AM »

Cranks been in the freezer overnight......Impact sockets are in the oven. I sure hope this crank drops in like everyone says it should.

Mike Grant · « **Reply #7 on:** January 18, 2015, 08:53:28 AM »

Cases are together. What kind of clearance should I have between the crank and the cases

dan580,95 moto · « **Reply #8 on:** January 18, 2015, 11:17:04 AM »

this is something i have been toying with at present see my crank overall width topic, i have ended up shimming my main in gear side 0.4mm to get my crank to sit bang in middle, i had a overall clearance of 0.8mm. which appears to be normal and a lot of people have kindly confirmed it. this site and members has helped me no end, if i could work out how to post my pics on here i could show u what i did.

Mike Grant · « **Reply #9 on:** January 18, 2015, 11:36:18 AM »

I ended up just giving the crank a few light taps to move it back towards the stator side. I was going by feel for the smoothest rotation possible. Turns smooth as butter and the only drag I can feel is the crank seals. Still looked like the crank was closer to the output in comparison. I just installed the top end and I can turn the motor over by grabbing the crank with one hand. Sure hope this is correct setup

DoldGuy · « **Reply #10 on:** January 18, 2015, 02:27:32 PM »

& you have a 5 speed?

Mike Grant · « **Reply #11 on:** January 18, 2015, 03:55:44 PM »

Nope......f**king engine is about to get smashed on the garage floor

DoldGuy · « **Reply #12 on:** January 19, 2015, 04:05:43 AM »

Mike,

Do you have the shifter on the shift shaft? If so, spin the output shaft by hand (if the counter sprocket installed its easier) & try to shift, what happens? Have you installed any oil (I use ATF initially to check / then drain prior to running)?

If you need to remove the top end for any reason leave the head on the cylinder to save the head gasket.

Don't give up yet! I'm sure with patience & everyone here, you will get it!

DoldGuy

Mike Grant · « **Reply #13 on:** January 19, 2015, 07:55:37 AM »

Hey DoldGuy.... I installed the transmission with no oil besides soaking the needle bearings on the input/output shafts and a few drops on the roller bearings. I didn't use any lube on the shift drum or shift forks because I was building the engine in my kitchen and didn't want to makes a mess.

If I disconnect the detent spring which rides on the shift drum I can turn the shift drum a few degrees in both directions smoothly before it stops. I have the sprocket on and it turns smoothly and currently is in gear. I have installed the shifter to try and get it too shift with no avail

I bought the transmission and shift forks off Roostius Maximus and had to install new bearings so I double checked all gears were in correct order with the thrust washers and circlips. I bought the shift drum off Sandlblaster and it should be the correct one for my bike.

Appreciate any ideas or help you can give

Thanks Mike

vagassasson · « **Reply #14 on:** January 19, 2015, 10:22:28 AM »

I think if the gear in the red box is installed backwards it can cause it to not function properly. I will double check when I get home later