Gregory Bender

Spline lube

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models


// //

I've found that typical grease on any of the Guzzi splines (layshaft [output shaft] splines on the transmission, u-joint, drive shaft, coupler, pinion shaft splines on the rear drive, crown wheel carrier splines, and rear wheel hub drive splines) simply heats up and flies off. This goes mostly without notice on everything except the rear wheel hub, where it spins out on the rim and tire making a mess of things.

That being said, I think it is important for these splines to be lubricated. If not, it is just metal working against metal and the result is a shorter life.

Note: I do not lubricate the splines on the clutch input hub. In my opinion, there is too much clutch dust that will get trapped by the lubricant and act as a grinding paste. I believe this does more harm than good and actually accelerates spline wear. If I were to do anything, I would have the clutch input hub treated using the process described by Tom Halchuk below.

What Gregory Bender uses:

A while back, someone in the Moto Guzzi National Owners Club (MGNOC) newsletter suggested using AMSOIL Fifth Wheel and Open Gear Compound. My experience has been very positive with this product and it has not spun out all over my rear wheel.

AMSOIL Fifth Wheel and Open Gear Compound (discontinued).
AMSOIL Fifth Wheel and Open Gear Compound (discontinued).

Photo courtesy of AMSOIL.

However, AMSOIL has discontinued the Fifth Wheel and Open Gear Compound product. Instead, they now recommend using Synthetic Polymeric Truck, Chassis & Equipment Grease, NLGI #2. I have not tried this yet, but will report back when I do.

Update regarding the NLGI #2 grease; contributed by Steve Odell on the old Yahoo! Loopframe_Guzzi news group (which has now moved to In Steve's own words:

I was using the 5th wheel lube until they stopped making it and switched to NLGI #2. It's the same stuff, just in a tube now instead of spray on. Extremely sticky, it will not fly off at any RPM that I've run, excellent for splines I feel.

AMSOIL Synthetic Polymeric Truck, Chassis & Equipment Grease, NLGI #2.
AMSOIL Synthetic Polymeric Truck, Chassis & Equipment Grease, NLGI #2.

Photo courtesy of AMSOIL.

Contributed by Joe Jump on the old Topica Loopframe_Guzzi news group (which has now moved to In Joe's own words:

I had a tube of the BMW red spline grease left over from my K-Bike days. Applied to my new hub, the splines in the flywheel, and to the splines in the friction plates using an old tooth brush. In 100 miles since finishing the job, no problems with fouling the clutch plates. Clutch engagement smooth as butter.
I think ol' Corntown used spray lithium grease on Creamsicle with no ill effects. I wouldn't worry too much about contamination of the plates, but I would try to select something that has a chance of staying in place.

Update regarding the BMW red spline grease; contributed by Paul Bonneau in a personal e-mail. In Paul's own words:

On the K lists I'm frequenting these days, this lube is universally scorned. I'm now having my driveshaft splines replaced because of the poor performance of this lube. I am giving GD-525 a try; see here what Ted of Ted's House has to say about it vs. BMW red lube.

Guard Dog Moly Lubricants GD-525 Moly Grease.
Guard Dog Moly Lubricants GD-525 Moly Grease.

Photo courtesy of Guard Dog Moly Lubricants.

Contributed by Ralf Brinkmann on the old Yahoo! Loopframe_Guzzi news group (which has now moved to In Ralf's own words:

I found some discussion about Optimol TA nowadays recommended by BMW as spline lube instead of Klüber Microlube GL-261 - the following thread includes a link to a data sheet.

Contributed by Chuck DeSantis on the old Topica Loopframe_Guzzi news group (which has now moved to In Chuck's own words:

Another option is Honda Moly 60 paste. I've used it on a bunch of different spline gears, even the rear wheel drive gear. Use sparingly so it doesn't fling; stays put and lasts a long time.

Honda Moly 60 paste.
Honda Moly 60 paste.

Photo courtesy of Honda.

Contributed by Carl Krall in a personal e-mail. In Carl's own words:

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 USD $38.00 a pint. (quote taken from Mark Johnson's FJR Site)

Contributed by Charlie Mullendore of Antietam Classic Cycle on the old Yahoo! Loopframe_Guzzi news group (which has now moved to In Charlie's own words:

Bruce Giller gave me a pouch of Permatex 5th Wheel Grease a while back. I've been using it since and it really seems to work well - no fling on rear wheel splines, nice and sticky for all the others. I just cut a corner off, squeeze it out onto a small brush and apply. Only USD $0.96 a pouch at my local heavy truck supply place.

Contributed by Brian (bostoneldo72) on the old Yahoo! Loopframe_Guzzi news group (which has now moved to

DuPont Krytox Synthetic Grease and Oil. Very expensive.

Contributed by Tom Halchuk in a personal e-mail. In Tom's own words:

I mentioned to you a while ago of a coating a friend on mine has used before. It is a extremely hard dry lube. He is a prototype machinist. We coated a few shafts in a test. Then tried to machine the shafts. It was almost impossible unless we gouged the surface first with a punch.

I coated my spline early last year. The clutch pull with the coating on the spline is very smooth and consistent. I have about 4K and 15 months on the spline.

The name of the company that made this is TechLine Coatings (Part Number DFL-1. POWERKOTE DRY FILM LUBE). To apply the stuff you need to first sandblast the area with very fine aluminum oxide at 40 PSI. Then apply the coating after mixing it very well with an electric drill or something. After this you then apply the material with an air brush to achieve an light but full and even coating. I found you can just paint it on as it seems to work just as well. After you let it air dry you then bake it in your wife or mothers oven for one hour at 350° F. After the part cools you then burnish the area with fine steel wool or even a fine wire wheel brush, this will leave what's left embedded as part of the metal surface and does not seem to add to the dimensions. It seems to me that any metal that can stand up to being baked at 350° F would benefit.