November 23, 2015

Classic Harley ratchet top transmission, complete tear down and total rebuild

I feel that was time for me to do a complete tranny rebuild thread ,I have done many sections over the years, but now why not doing it totally this time,hope you will enjoy
Here it is …as I received the tranny ,1965 OEM tranny that came with my early FL66 project

Open the top, here is what the inside looks like,not too much rust at least, been on a non heated garage for at least the last 13 years

Took the kicker cover off than take off the lock tab and nut at the end of counter shaft,but before here is what I found washer and cutter pins was in the bottom of tranny

Next take off the complete cluster assembly

See the loose rollers at the end of cluster gear,those will be replace with a new gear with caged bearings,more on that later


Then time to take the kicker gear with my special puller


Took off the bearing lock plate

Some slight tapping at the end of main shaft with brass hammer so the 6305 bearing at the end of kicker gear could find it’s way out .

As soon as it start to come off you need to get the lock ring out located against the shoulder of the third gear on main shaft,
Note here never re-use the lock ring always use a new.

As you can see now everything should come out.

Grab the main shaft in the vise to take off the lock tab,nut and bearing so main shaft is all by itself


Some located rust here and there ,but that should clean up.

Time to clean everything and check every gears and shafts,many gears has been throw away due to gear pitting of bad ramps,change many of them but not all,used some stuff I had in my stash,the main drive gear is now a new Andrews with my special update with new bushing and 2 small seals,
The kicker cover shaft is still oem,machine down to .740 inch ,new bushing in kicker cover,new o-rings,an extra seal has been install in kicker cover,all bearings change to new style with my special kit to receive the B2610 in main drive gear and two B1212 on each end of cluster gear,cluster gear has been change for a rear nice one that I have ,also machine to accept the later caged bearing,you will see more as we go on what was done …

Kicker cover,ratchet top and tranny has been blast,clean,re clean,re-clean…then paint with VHT cast aluminum high heat


Here is what I do first ,fitting the end trust washer with correct ones,the old one was change to a thicker ones,backlash was at .023 way too much, always try to have at least .008 inch and no more than .015 inch backlash,you could also see in the picture the new inner bearing race to accept later caged bearing.

The rebuild used cluster gear with oem speedo gear

You can see the sleeve between cluster gear and bearing,this one has been machine to accept later B1212,either you could buy a later one, or use what you have on hands like I did,I did all my machining so it is easy for me but not for all.


Time to assemble the cluster shaft assembly,nice used bushings with correct tolerance were use,not the one that were in previously, but excellent condition one I had on hands from a previously rebuild

Gear washer and new spiro-lock to secure gear in place

New shifter dog were use with new shifter fork,you can also see assembly lube


Everything ready with end washer secure with some thick synthetics grease to make sure it stays in place


I forgot to take picture of the main shaft assembly ,but here is some pictures from a previous cowpie rebuild,similar assembly even if they were both different tranny,inner guts are similar.
You need to install main drive gear into the B2610 bearing, then slide main shaft via kicker side with shifter dog,lock ring,washer and third gear,remark here you can see first and second gear are in place,with bearing and outside race ,secure in place with lock and nut on the kicker side,all assemble in the vice before getting the main shaft into the case.

Cluster assembly ready to be install into the case


When cluster is in place don’t forget to install your new trust washer to end up with .008 inch backlash,not less than that or it might be dangerous that tranny seized on you.

Secure the screws with blue Loctite

Time to install oem kicker gear with new bronze bushing fit to the oem shaft that was machine down slightly to .740 inch instead of the oem .750 inch.

You can see oem outside kicker gear with 2 keyways

Don’t forget to bend all the lock tab,you see a new pushrod bushing at the end of the oem main shaft,none was in place when I took it off,I felt it was worth the time doing it.

Oem kicker with new bushings,two o-rings in the middle ,instead of the square rubber band,the two o-rings are between the 2 bushings, and with an extra end seal for better sealing… I also add a new custom made fill cap



I re-use the oem kicker start gear until I find a better one,even if teeth were slightly worn,.
I felt that oem even worn are far better than reproduction these days.

Time to take care of ratchet top cover

When this shifter gear has been time correctly install the drum and make sure timing mark are align,I use permanent marker,easier that way

New spring pawl carrier,really important,always use new springs.

Install with parts facing other ways


Time to change shifter forks with new Andrews forks.

Special tool for a special job to adjust precisely side plays of forks in between gear,this could be done without it but when you have it,use it cause it is easier and faster that way,shifter dogs when adjust properly make your tranny shift lot smoother.

Install the tool on the ratchet top adjust with straight slot then lock in place

Then make sure wing nut are secure ,reverse and install on top of tranny

Both shifter forks were slightly off,one by .007 the other .014,shims come in .007 and .014 inch,so it was quite easy, just make sure either you add or take off shims and on what side of forks,always bend locktab when done.


Main shaft shifter dogs need to be.100 inch between both third and main drive gear and cluster gear shifter dog should have .075 inch between first and second gear



I did check backlash and I found .015 inch ,Harley specs ask for .003 to .013 inch backlash so instead of using a thicker main drive gear trust washer I decide to counterbore the o-ring spacer by .008 inch to end up at .007 inch total backlash,

Note :backlash could have been check before cluster assembly was in place,I did re-use same main drive gear trust washer in this case but could have order a thicker one for my application,i did not want to wait for a new one, this is why I end up recessing my spacer.


Note here that sprocket nut should be install to check backlash


Seal should be install with spacer together,I use primer and green Loctite on both case and outer of James main drive seal.


 custom made tool made of teflon to get the main seal in
Time to seal top and cover,I use Hylomar on both face of gasket
Here is the tranny finish and ready to be bolt in my new project,some link to my previous thread for those who would like to see how thing in this thread was done.Hope you have enjoy this long thread,saddlebagrail


Filed under Engine & Transmission, Random Ideas, Resources, Saddlebagrail's blog, Tech by saddlebagrail

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