home modifications maintenance rides links misc

Drive Shaft Spline Maintenance

Here's the photo that started the whole ball rolling on how important it is to check and maintain the drive shaft splines on your FJR1300.

On April 4, 2003 I did my first tire replacement and final drive service. What I discovered about the condition of the drive splines had me concerned enough that I sent copies of this photo to FJR Owners, the FJR EZBoard site, and to the Micapeak mail list. I voiced my concerns based on my long experience with shaft driven Hondas and was asked by H. Marc Lewis to write up something for his FJR1300 Info web site. At the time I wrote that, I made some assumptions about the reader's background with shaft driven motorcycles. That may or may not have been appropriate. The additional information is now included.

At 6k miles I did the first tire swap. While in there I checked the splines to be sure everything looked okay. This is what the Yamaha assembly drones consider sufficient for the job. After initially writing about this, some other Feejer owners have e-mailed me and told me their's was just as "dry". It's not a good thing, folks. Check your splines each time you do a tire swap. It's quick and easy and can save you a load of heartache over the life of the bike.

1. Get a factory service manual. It's cheap insurance.

2. Remove rear wheel (including brake caliper from rotor, etc.)

3. Remove the 4 acorn nuts to the front of the rear drive "pumpkin" where it bolts to the swing arm.

4. Carefully pull the assembly straight backward. The shaft will come with the pumpkin.

5. [3rd Update 6/25/06] After much discussion, debate, and opposing opinions*, it has been confirmed that the rear drive shaft splines ARE lubed by the final drive gear oil (in the "pumpkin"). Even so, it is adviseable that you service the rear drive shaft splines and oil seal #2 occasionally.

There's a circlip (#1), an oil seal (#2) that do not need to be removed to pull the shaft from the pumpkin (the shaft is a friction fit). You can service them in place on the shaft once it's pulled. If you do R&R them, replace them carefully to prevent damage. There's also a spring (# 4) between the rear of the shaft and the front of the "pumpkin" that needs to kept under control and reinstalled when reassembling. Servicing the splines at the front & rear of drive shaft, male and female splines of the rear wheel assembly, the engine output shaft, and the u-joint are vital. For the front drive shaft splines and the rear wheel hub (drive and driven splines), cleaning and lubing with Honda Moly 60 Paste can't be emphasized strongly enough. Oil seals #2 and #14 are identified as needing "lithium soap base grease".

Previously-Serviced Rear Hub Splines At Tire Swap

Rear Hub Splines Cleaned & Ready For Honda Moly 60 Paste

6. Clean and lube the front splines & clean the rear splines and lube seal #2. I found that Mobile Super Syn grease was the exact same color and consistency as that already on the front splines from the factory. With BMW and others re-labeling Mobile synth products, my bet this is the same story with Yamaha's rear pumpkin "magic juice" they sell for $38 a pint. Clean/lube the rear hub splines (drive & driven) while the tire is out too.

7. Cleaning the splines before slathering more lube on them is important to reduce the abrasion that dirt and grit causes.

8. While Mobile Synth lube is okay and appears to match the slight hint of lube used by the factory, Honda Moly 60 Paste is the preferred choice. For years Gold Wing riders have known how great this product is. Many non-Honda shops use it too. The high moly content means that it resists the high temperatures and pressures to which drive line components are subjected. It's less likely to flow away from the areas needing protection; even when stressed under extreme use. Many a Wingster has found their splines crumble to dust if neglected. If Honda Moly 60 can hold up under the stress of a fully-loaded Wing, (2-up, pulling an overloaded trailer), then it should be okay for the FJR1300. I couldn't find any Honda Moly 60 paste prior to the first tire change, so used the Mobile 1 that was on hand. Since then I have found and bought some and use it instead.

8. Reassemble in reverse order, being careful to line up the splines so they slip right in without being forced. Be sure to also clean and grease the splines on the rear drive where they mate to the rear wheel. Use care when reassembling the rear spline's spring, oil seal, and circlip.

9. Torque the 4 acorn nuts on the rear hub to 42 Nm (30 ft-lbs).

10. Do not torque the acorn nuts down until after the rear wheel has been reinstalled and the axle torqued to the proper specifications. This will help assure a better alignment of the assembly.

11. Go ahead and swap out rear drive ("pumpkin") lube while you're in there. You don't have to with the above expensive Yamaha gear oil, but why not? It's fast and easy.

12. Perform the Universal Joint Service too while here. It's easy.

Since I first found out how poorly lubed the FJR was (as delivered by Yamaha) and initially reported it, several others have taken the ball and run with it to great results. Their detailed tech instructions are one of the many reasons that the FJR has earned such a great reputation so quickly. Marc's page was later joined by Dale Wilson's service procedures at FJRTech.com; both sites are excellent resources for FJR owners around the world.


* The discussions have centered around the purpose of the oil seal. Some said it was to allow the rear spline to be bathed in rear drive gear lube others weren't convinced and pulled the rear spline to find channels for the oil to pass from the rear pumpin, into (and back out of) the area between seal #2 and seal #14. SkooterG's detailed discussion and photos.




All material on this site (c) 1995 - Present, Mark Johnson. All rights reserved.