Drivetrain Alignment

Article By: Corey Barnum

Photos By: Craig (Uber) Harriman

Originally Published In The April 2020 Issue Of Cycle Source Magazine


We recently had a customer come in to have a routine service done on his 2012 FLTRX. Upon doing the standard service procedures, I noticed his front engine stabilizer link (Heim joints) were wore out. In 2009 Harley- Davidson changed the frame and went to a nonadjustable stabilizer link. I’m sure this decision saved money in production or reduced error in the service department. However, for the technician or individual who strives for perfection and wants the best out of a motorcycle, the nonadjustable stabilizer is a poor choice. When given the chance, I prefer to replace these “new” linkages with the “older” adjustable version. This allows me to fine-tune the alignment of the drive train thus improving both power transfer to the rear wheel as well as handling by balancing the rear suspension. This tech article will illustrate how adjustments to the stabilizers can affect the distance between shock mounts and essentially remove any twisting of the driveline. This alignment will also have a significant impact on the life of your tires by reducing cupping, which is a common issue with bikes 2009 and up.

The first thing to do in this procedure is to get the bike in the upright position. I usually use a jack under the frame. Jack it up enough to relax the rear shocks and level the motorcycle.

As you can see in the next two pictures, I am able to move the

stabilizing linkage with my hand. Any movement of the link indicates that it is worn out. Make sure the motorcycle is in the upright position to take the load off the link when doing this.

After checking the condition of the link and determining if it needs the be replaced, I purge the air out of the rear shocks and remove them.

Using transfer punches from the fabrication room in each one of the shock bolt bosses allows me to find the center of the holes thus allowing an accurate measurement of the distance

Using a precision machinist’s scale, I take a measurement between the upper and lower shock mounts to see how far off the alignment is from

side to side. As you can see in the two pictures, this bike is about 1/16” off between the left and right side. Again, this may well be acceptable and fall under “factory tolerances.” But we are not here to do average work, and this shop runs under a different set of principles. So given the opportunity, I’m always going to correct a misalignment

Using a T45 Torx bit, I then remove the old worn out stabilizer link.

Here is a picture of the two different stabilizer links. I always try to get the  adjustable one close to the length of old link for a decent starting point.

After getting the link close to the same length, I install it onto the bike. Torqueing the two bolts to 20 ft-lbs.

Once torqued, I then take another measurement of the shock mounts and start to make my adjustments.

After a little bit of adjusting the link’s length I was able to get the shock

mounts to be equal distances from each other on both sides.

Once the bike is in alignment, make sure to tighten down the lock nuts on both sides of the stabilizer link.

Next, reinstall the shocks, torquing all four bolts to 40 ft-lbs.

With the shocks torqued and the airlines reconnected and pressurized, I always test to make sure there air no air leaks in the system. I understand that this procedure may be viewed as unnecessary by some, and as a master level technician at a dealership, I had to stick to the OEM parts and design for many years. This was always frustrating to me when I could see areas that I knew needed to be improved. However, working at Faith Forgotten Choppers with Will I have been given the freedom, and even encouraged, to take my work to the next level and put the customer and the performance of the bike before the bottom line. For some people, there is a true reward in knowing that you are completing jobs and holding yourself to the highest standard. The satisfaction of our customers and

the continuing growth of this service department is testament enough for me that this type business plan can still work today. Ride Safe -Corey

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