Shimano Nexus 3 Speed Hub Manual

Shimano SG-3D55 3-speed hub with disc brake The current (2017) generation of Shimano 3-speed internal-gear hubs is available with a coaster brake or with an optional external Rollerbrake or disc brake. The coaster brake is only suitable for flatland use: it will.

Shimano Nexus 7 Complete Assembly Manual dvlrd56ewj4z Amazon.com: SHIMANO SG-3C41 Universal Hub Kit Nexus (36H 3. Owners Manual For All Chainless Bicycle Models - Dynamic.
SHIMANO NEXUS - Internal Geared Rear Hub - CENTER LOCK - Disc Brake - O.L.D 135 mm - 3-speed The SHIMANO NEXUS SG-3D55 hub offers a reliable 3-speed mechanism, a SILENT CLUTCH, and CENTER LOCK disc rotor interface. Internal geared hub for Disc Brake version Gear Change Support Mechanism.

Today, we’re going to work on internal multi speed hubs. This is the Shimano shifter. It is the Nexus model, which is written on the body. Another way to tell that this is Shimano is that the cable chord goes straight into the adjustment knob, which goes straight into the body of the shifter.

Now, the first thing you want to do is go up to the shifter on the handlebar and put it into second gear, the middle gear. You need two tools: an open end 10 mm wrench and you may also need a pair of pliers.

The first thing you do is loosen the lock nut right up against the body of the shifter. Loosen that and it allows the adjustment knob to be free. Sometimes you will need a wrench to move it. You will see there are two lines in the window of the shifter and there is a piece inside that has a little yellow indicator. You want to line that yellow between the two lines with the adjustment knob. When you get the yellow right between the two lines, go ahead and put the lock nut right up against the body of the shifter, and tighten it with the 10 mm wrench, so that adjustment stays nice and firm.

Now you’re done. Take it for a ride and make sure it shifts properly.

There are many benefits of using an internally geared hub. For the most part, the unit is sealed off the elements, you can use them in a belt drive system, they shift really fast, etc. When we get one of these hubs from Shimano, or on a built bike, they come packed full of grease. With most Shimano internally geared hubs, grease is used to lubricate moving parts. However, here in Minnesota, extreme temperatures can change the way grease acts, especially when you're dealing with gears only a few millimeters in diameter.

Today we will talk about how to clean, service, and re-lubricate (with winter in mind) a Shimano Nexus 8 speed internally geared hub.

First, we need to remove the external components. Turn the shift mechanism locking to the left and the shift assembly slides right off.

Remove the cog snap-ring. This thing can be a huge pain. Unhook it from its groove and get a screwdriver under it. From there, all you have to do it walk it around till it comes off. I like to wear safety glasses of some sort when doing this. Snap-rings can be unpredictable at times.

Shimano Nexus 3 Speed Manual

After the cog comes off, there is a dust shield and seal exposed.

Once removed, the drive side is now prepared for the cartridge to come out.

This bike is equipped with a roller brake. It's almost like a drum brake that's actuated with a hexagonal nut looking thing that 6 rollers rotate around pushing pressure plates against the inside diameter of the braking surface.
There is one nut that holds the assembly to the hub shell. Once that's removed, the whole brake comes off.

We now have access to the wench flats of the cone and lock-nut. These can be completely removed...

Shimano Nexus 3 Speed Hub Manual Transmissions

The dirty, greasy parts get a nice hot bath in the parts washer. I usually let the cartridge sit for an hour or so to allow the old grease to break down.

Here is an exploded view after the parts are all cleaned.

Must be 'Blue Razzzberry.'

The cartridge gets soaked till it's good and saturated. I usually wait till the bubbles subside.

Clean the inside of the hub shell.

Apply grease to the bearings and clutch rollers. I also inject 3cc or 4cc of the special Shimano oil (ice cream topping) between the gears before putting everything back together.

Reinsert the cartridge and wipe off the excess grease.

Re-adjust bearing on the non-drive side till there is no play.

Grease back of dust shield and reinstall.

Grease the back of the cog and reinstall (We have had issues with these making noise, and grease seems to solve the problem).

Realign red dots with red, yellow dots with yellow...

... And rotate lock-ring to lock the shift mechanism in place.

It's good practice to lubricate the roller brake regularly. Squirt some special roller brake grease in the grease port.

Loosely install the roller brake. Tighten the drive side axle nut, align the reaction arm, then tighten the roller brake nut to fix it to the hub.

Seat the axle in the dropouts and fasten both axle nuts. Align belt if applicable. Check all the gears to make sure there are still 8 of them. If there aren't as many as when you started, something went wrong. Shift into 4th gear and use cable tension to align the two yellow marks in the window.

After performing this service, the hub felt like it shifted faster and more crisply, especially in the extreme cold. One of our year-round commuting employees, Ben, who uses the same hub described the overhaul to make the shifting 'less gummy and more direct. It gives me all of it,' he concluded. I'm not really sure what that last part means, but it sounds pretty positive.