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Installing The Baker XL6

6-Speed Overdrive for your Sporty or Buell

Photos and Copy By Digital

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Sportsters...... I love 'em. Light, tight, quick, and always ready for a street brawl. There's just one problem: The availability of aftermarket parts. Although the aftermarket industry has yet to fully embrace the Sportster rider as a marketing force, Baker Drivetrain is one company that is bucking the trend.


What you see before you is the recently released Baker XL6 6-speed transmission for your Sportster or Buell. I've had this one in my bike for just a couple weeks now, and I've got to say - this is THE TICKET for anyone screaming down the highway or wanting to raise some eyebrows in between stop lights.


The unit comes packaged in polystyrene and complete with transmission, shifting drum, forks, pins, low-effort detent spring, a template for minor case mods and installation instructions.

My test sled was my Softail Sportster, built just last year. It's a 1200 XL with a stock 30-tooth pulley on the secondary. At 80 mph, it feels like you're doing 65 with about a 550 rpm drop. The top gear is a .86 overdrive, as opposed to the stock 1-to-1 gear ratio of the stock unit. This is interesting because it gives you barn burners out there the option to drop the tooth count on the secondary pulley, gain about 8 percent torque through the gears, and still retain the stock overall gear ratio at the top end. It's also got a trap door about as thick as the armor on a battleship. As anyone who races Sportster motors knows, the week point of the stock engine is the trap door. Baker's is made of about a 1-inch-thick piece of T-6061 billet and it's about five times stronger than the stock door.

So, let's get to the installation.


First, we remove the shifting arm from the outside of the primary and remove the primary cover to reveal what you see above. At this point, we need to remove the clutch basket.


With the help of a spring compressor from Custom Chrome, we remove the diaphragm spring.


We now have access to the two shaft nuts that have to be removed to allow for removal of the primary chain, clutch and front rotor/sprocket assembly. You will need an impact wrench and a couple large sockets to get these off. The impact/ air wrench takes advantage of the inertia of the motor and basically bangs the nuts off rapidly without you having to hold or jam the assembly while you muscle it off with a torque wrench. There is one thing to note - the transmission main shaft nut is a counter clockwise thread, so don't beat on it all day in the wrong direction trying to get it off.


For this project, the rotor was placed back on the front shaft just to keep it somewhere clean, but you can take it off for working in this area. It's magnetic and wanted to stay on the stator, so we gave it a good tug and it came right off.

What you are looking at in the photo above is the stock shifter prawl, detent plate, detent and detent spring. The stock plate is held on with a spring clip. As you will see later, the Baker model is held on with a screw.


Remove the detent plate, shifter prawl and detent spring (loose in the photo above) and get ready to unbolt the four bolts on the trap door.


Once you unbolt the four bolts holding on the trap door, the entire cartridge assembly is removed by pulling it toward you. The stock unit is above. Note the door thickness and webbing on the cast piece.


Once you have the unit out, you can see the stock 5th main gear (still in the case) with the main shaft, counter shaft and shift drum bearings still in the case. Note the template at the top - we'll get to that in a minute.


The next step is to modify the case. Baker sends a template to guide a die grinder or Dremel tool to make clearance for the 6th gear, which is sunk into the trap door. We mounted the template (as shown in the previous photo) and isolated the area with some shop towels. This is a messy process, so you want to make sure you keep the shavings OUT of the case.


To properly modify the case, use a Dremel tool or a die grinder with a medium burr. The cut you will make must follow the contour of the template as shown. The back-cut must run about 3/4 of an inch. I went back 1 inch just to be sure. You DON'T want the gear in contact with the case. When complete, remove the rags, blow it out with air and clean with a brake cleaner or other solvent to flush out all the shavings.


Now we're ready to prep the transmission. We must remove the stock 5th gear and place it on the Baker countershaft. It is held in place with a snap ring, so it will be helpful to have a good set of snap ring pliers. YOU MUST PUT THE GEAR ON IN THE SAME ORIENTATION AS STOCK. Wear patterns occur in these gears and you need to keep the wear patterns in the same orientation as before.


Next, we must place the shift forks on the drum and mount them in place using the drum pins and cotter pins supplied with the kit. The manual details the exact orientation of the forks.


The forks are then put into place over the two shafts as shown above. The new detent plate is then fastened onto the end of the drum on the right hand side. This photo gives you an idea of how thick the door actually is. You can also see how the top gear set is recessed into the door. At this point, you will also need to re-attach the detent, which restrains the detent plate.


The shifter prawl also needs about .100 inch ground off the tip to make clearance on the new door.


Next, the gear set was slid back into position in the case and bolted down.


The prawl was put back in place and adjusted per the service manual, and the low effort detent spring was installed. I highly recommend you get a Harley service manual for this job. Adjusting the shifter prawl and the proper bolt torques are all critical to reassembly.


The clutch basket, front sprocket and diaphragm spring are then re-installed, and you are ready to re-mount the primary case. Remember to get a new primary gasket and hold it in place with a little grease to make re-assembly easier. Torque down your primary cover, adjust the primary chain per the service manual for proper play and you're ready to rock.

A couple of side notes. If you have a pre-1991 XL, ask Baker about upgrading your 5th gear to eliminate any gear whine. Reverse pattern shift drums are also available for those who like to upshift by slamming their foot down, rather than pulling it up.

Later - Digital

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Reader Comments

Great article! Would love to get one. Rubbermounts ('04 and later) require you to split the case for any trans work. Lucky for me I have an '03! This article has me seriously thinking about a 6-speed instead of head work!

League City, TX
Thursday, June 1, 2017
Editor Response Lisa Baker said she would get back to you. Could be the right choice, but in addition, I would do the heads with Branch, add some cams and fly.
A really great breakdown I couldn't ask for better, now I can better understand how my tranny works.


keith burford
shippensburg, PA
Saturday, January 30, 2016
Editor Response No problem, anytime.
Love it. Just sold my Dyna and bought a '13 Sporty 48. Only thing I miss is gear #6.

Disappointed to find out Baker no-makey the XL6 for anything newer than 2003! How do we convince them that making a newer XL6 is a good idea given there is a DECADE's worth of Sportsters out there needing overdrive?

El Fontain
Kansas City, MO
Saturday, July 27, 2013
Editor Response I will send a note to the mountain.

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