Editor’s Note: The following tech was written and photographed by the Lucky Devil Metal Works crew who are primarily responsible for the Salt Torpedo build. Kent Weeks and his wife Holly did a helluva job at documenting this process.
I have installed a few gear sets but I think no matter how many times you have done it it’s always a good idea to check out the instructions before getting started. Some manufacturers products are slightly different from each other and sometimes changes have been made to the install process so if nothing else a quick read though never hurts.
JIMS recommends that you have a good manual for the bike as well as a 2002-2005 big twin service manual and parts book for reference, even if you’re a seasoned mechanic this will provide torque specs and exploded views in more detail than a service manual or product install instructions.
With this project we are using a new 2000-2005 FL Harley-Davidson Transmission case, so there was no disassembly required, if your replacing a stock gear set just follow the instructions in the proper H-D service manual.
Normally, when I am installing a gear set in a used case still in the motorcycle, I clean it out with solvent to remove as much oil residue as possible to help the tape stick and make clean-up easier, but this time I went straight to covering all the areas mentioned in the Fat Five instruction manual.
After tape prep was done and I installed the drill plate in the proper location (easy to do with the light engraving notice “this side out”) I used some shop rags to line the inside of the tranny case to catch all the shavings, even though with a dry case it is easier to clean up the mess. As per the instructions I drilled out the shift fork shaft starting with a 3/8-inch drill bit and ending with a ¾-inch drill bit, from there I used an aluminum rotary file in a die grinder to clean up the rest of the material right up to the drill plate.
Once the drill plate was removed I took the edge off the area where the work was done, and while I had the inside taped up, I went ahead and cleaned up some slight casting flaws in and around the shift drum opening to smooth it out.
It is extremely important to take some time with the clean up because it doesn’t take much to trash a new set of bearings! Once I carefully removed the shop rags I used a little solvent and compressed air to blow it out, before removing the tape and basically cleaned it again to be sure there is nothing left behind. Because we are using a new case on a bench it was possible to roll it around and get it right next to godliness, as they say.
Because we are using a 2001-2006 FL tranny case the top cover does not need to be modified for additional clearance, though just for grins I always like to check it anyway just to make sure. It has never hurt me so far, ha-ha!
I did not need to push in a new main drive gear bearing because new Harley cases come with one installed, but if you are working with a high-mileage case you will need to make sure you get this part of the job done right.
(As you might imagine JIMS has just the tool for the job # 35316-80)
For some reason, I have gotten into the habit of installing the shifter shaft before the main drive gear, backwards from the directions and in this situation the countershaft bearing has already been installed at the Harley Factory. To install the Main seal use JIMS tool No.95660-85 with tool # 95660-42 following the service manual instructions, for the drive gear use JIMS tool # 35316-80. The instructions are also covered in the service manual.
For the next step I set the 3rd gear fork and 4th gear into their proper shift rings and laid them down towards the countershaft, so they can clear the case on the way in (the last shift fork is installed after the gear set has been installed into the case).
To get ready for the next step I installed the trap door gasket over the dowel pins on the tranny case and put a little lube inside the main drive gear. The main-shaft has a protective cover over the splines to help protect the seal as it is being installed through the main drive gear, so making sure it was in place until you’re ready to install the clutch basket.
With the gear set installed and trap door in the case and torqued to specs, the last shift fork gets to find it’s way home through the top cover opening and into the proper shift ring. Now the extended shift fork shaft can be installed though the hole in the trap door, all three shift forks and into the left side of the tranny case. It is important to make sure the shift fork shaft has about .020 end-play when you install and tighten the set screw.
Because we have not determined the offset and tooth count for the main drive sprocket yet, I will not finalize the install at this time however I did install the quad seal and main shaft seal spacer. I also fitted the shift drum in place even though I will pull it out to torque the main drive gear in place once we’ve got the right one in hand.
To do so with the shift drum removed, slide all three shift rings so they all engage into mating gears to lock the tranny and keep the gears from turning while the sprocket mounting nut it torqued to spec. From there, the clutch throw out rod assembly and primary drive can be installed followed by the shift drum assembly and side cover.
We’ll get to that later. Also, we have yet to determine if we’ll run a cable or hydraulic actuator to operate the clutch so there will be more to come on this part of the project as shit flies together.
Hang on!
JIMS USA
Paughco
Lucky Devil Metal Works
