How to Reduce the Chance of a Rear wheel Lockup

Secondary Gearbox

The most common failure of the secondary gearbox is from a lack of lubrication. This lack of lube comes about in a couple of ways.

Plug Failure

Inside the secondary gearbox there are two hypoid-design gears, the drive gear, driven by the output shaft of the motor, and the driven gear which transmits the power to the driveshaft. In the end of the driven gear is a rubber-coated steel plug that seals a hole through the gear. It is common for that plug to simply fall out into the box leaving a rather gaping hole for the gear-lube to escape from. Luckily, at the other end of that hole is the driveshaft and, since it inserts into the driven gear with splines, there is at least some resistance to gear-lube escape and it may take some time for it to become dangerously low. Reports from several Cade owners indicate the level can get to a dangerous level in about 2000 miles or less.

Ultimately, when the lube reaches a dangerously low level, heat buildup within the gearbox will cause the tapered roller bearings (primarily the drive-gear, inside bearing) to overheat and they will either start shedding bits of their surface or will start to weld themselves to the races. This can stop the rear wheel in its tracks instantly.

Riders should not depend on an external visual indication of lubricant loss. Since the boot seals the rear of the secondary drive to the driveshaft tube, a leak may not be visually detectable as a drip or spotting on the garage floor. The level of the fluid in the secondary must be checked at regular intervals. Even though there are several reports of approximately 2000 miles before the gear oil reached a dangerous level, that should not be used as a guideline for checking the lubricant level. In an instance that might include rider and passenger of substantial size, with loaded bags and trunk and a trailer, heat buildup due to a less-than-full level of gear oil could reduce that mileage drastically.

Author recommends that the gear-oil level in the secondary be checked frequently. Maybe even every 500 miles or less. I check the level each time I check air pressure in the tires. One member of the Cavalcade e-mail group has designed a simple but very effective dipstick that can be inserted into the fill hole of the secondary to negate the need to remove the chrome cover over the secondary and withdraw the level-check screw. You can see a picture of the dipstick by clicking here. Author is making dipsticks according to the noted design and offering them for purchase. Click here to see it and it's use.

While Suzuki has increased the length of the rubber-coated plug to expose more surface area of rubber to the ID of the driven gear, the fact remains that the rubber, over time, will lose its elasticity and compression set. As the rubber takes a set, it exerts much less force on the ID of the gear and, in most cases, it simply falls out into the gearbox.