Shimano Nexus 3 Speed Hub Manual

Shimano Nexus 3 Speed Hub Manual -
Shimano Nexus 3 Speed Diagram
Shimano Nexus 3 Speed Hub Manual Download
Shimano Nexus 3 Speed Wheel

IMPORTANT NOTICE 5 IMPORTANT NOTICE This dealer’s manual is intended primarily for use by professional bicycle mechanics. Users who are not professionally trained for bicycle assembly should not attempt to install the components themselves using the. Watch as Pete on the Beachbikes.com Mechanics shows us how to adjust a Shimano Nexus Internal 3 Speed hub on a sixthreezero Classic Edition 3 Speed Beach Cru. Shimano Nexus 3, 4, 5, 7 and 8-speed hubs are currently in production as of 2014. Alfine is a high-end product line with 8 and 11-speed hubs. Alfine hubs feature fancy features including optional hydraulic disc brakes and electronic shifting. SHIMANO NEXUS - REVOSHIFT - Shift Lever - Window Display - 3-speed The SHIMANO NEXUS SL-3S41E shift lever feature a low-effort rotational shift action that doesn't depend on finger strength and allows riders to keep their hands on the handlebar while shifting. Jan 17, 2011 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.

Shimano Nexus 3 Speed Hub Manual -

Shimano Internally Geared Hubs

We have all colors of non-turn washers in stock.

Shimano Nexus SG-8R20 8-Speed Internally Geared Hub with Roller Brake

This hub was ridden less than one year in Seattle. Neither the shop nor Shimano used enough grease and oil for NW weather.
If you bring us your bike we can preemptivly weatherize your hub and avoid expensive repairs.
Unfourtunately, the only way to fix this hub is replacement. The hub shell bearing races were badly pitted. The hub functioned, but with a very loud rumbling noise.

2013 Update: Current Shimano production adds ample grease for most fair weather users. However, in wet climates we still recommend an initial weatherization/overhaul at 1000 miles. After that, every 3000 miles or 2 years is fine. Daily commuters should have their hub overhauled once a year regardless of milage.

Below are pictures of an overhaul of a Shimano Nexus SG-8R36 'Red Band' Hub

The shift mechanism of a Nexus and Alfine hub are identical. An exploded diagram is not available and Shimano lists it only as the Hub Axle Unit.

Care must be taken when disassembling the hub as to not unlodge any of the parts. They are held together by a friction washer with a light press fit.

The weaker spring on the left is what Shimano calls the Pre-Select spring. It allows the shifter to select a gear when the hub is stopped. The stronger shift spring on the right is what acually moves the shift pawl cam. If you leave the pre-select spring engaged for a long time it can weaken and cause the hub to malfunction. Shifting an IGH hub is akin to a shifting car. You need to push in the clutch! Do this by lightly pedalling, not pedaling or even slightly pedalling backwards when you shift. If you shift under power you can cause the clutch to remain in the same gear until your pedal stroke has a dead spot. Then the clutch or axle pawl will disengage or the clutch will move causing a loud pop or clunk. Repeated derailleur-style shifting can cause cause parts of the axle unit to bend or flex causing shiting issues. The solution is usually a new axle unit.

If you accidentally take this assembly appart, we can re-assemble it for you, or follow the instructions we published:

Shimano 8 Speed Axle Unit Reassembly Instructions.

The Drive side cone is not sealed as well as it could be. A cartridge bearing would be superior, but Shimano is committed to cup and cone type bearings. Therefore, proper lube is necessary. Factory lube is not enough for daily or Northwest use! And neither is Shimano's recommendation to just dip the guts in oil. the hub MUST be periodically completely dismantled as shown and cleaned, re-lubed and have the ball bearings replaced. There is no other way to get the bearing races to last. The picutre below is a sad example of what can happen. Often we can re-machine the races on our lathe, but this one is too pitted for that. Thankfully now this part is available as a spare.

Above is the Driver Unit disassembled (pawl version).

Shimano Nexus 3 Speed Diagram

Below is the Driver Unit disassembled (friction ring version).
These 5 parts replace the pawl carrier pictured above.

Both driver types are interchangeable. The Friction Ring version will rotate clockwise or counter-clockwise, the Ratchet version will only rotate counter-clockwise. This test is done while looking at the inside of the Driver Unit using a pair of large snap ring pliers (example Snap-On model SRP1C)

Shimano SG-S700 Alfine 11 Speed

Above is the right side axle seal that sits outside the cone.
As you can see it is a very complicated seal and it often leaks.
It can be removed, degreased (and the seat it sits in), then coated with 100% silicone.
This will fix the axle oil leak, but oil may still seep out the larger main seal.
The main seal should be replaced every oil change to prevent leaks.
Also, never lay an internally geared hub on it's side for long periods of time.
If you need to transport a bike horizontally, lay it on the drive side and put a rag under it!

Shimano SG-S700 Hub Gear Oil before and after 1000 miles (no previous oil change).
Change your oil every 3000 miles. (the first oil change is at 600 miles)
Use only Shimano SG-S700 Oil in the Alfine 11 hubs. Other lubes may cause seal swelling or deterioration.
Oil compatible grease may be used on the bearings. We find it helps slow oil seepage.
We recommmend and use Buzzy’s Slick Honey in Alfine 11 hubs.

IT IS OUR EXPERIENCE THAT ALFINE 11 SPEED HUBS SEEP OIL OUT OF THE MAIN SEAL.
WE NOW CONSIDER THIS NORMAL! SIMPLY WIPE OFF ANY EXCESS AND ADD MORE OIL PERIODICALLY.
Newer hubs seem to leak less than previous.
If the seal is over-torqued it will deform and leak.

Shimano Alfine SG-S500 & SG-S501 8-Speed Hub

Above is a picture of the factory lubrication.

Shimano SG-S501 Alfine 8 Speed Hub
This hub was used for about 3 years. If you are looking for parts for these hubs contact us.
Shimano only offers the entire 'guts' unit (#1 in the diagram). We find it odd because part numbers 11, 15 & 16 were the only parts worn!
Additionally, they sell the tools necessary to replace just those parts! You can see them in the diagram, we own them.
We can add waterproof grease to your hub and prevent this wear from happening.
The pictures below show the proper lube for the Pacific Northwest.

We are using Sta-Lube Blue Marine Grease.

One fluid ounce of Phil Wood Tenacious Oil

Shimano Nexus SG-C3000-7R 7-Speed for Roller Brake
Axle Assembly Pictures
Instructions are very similar to Keith Lang's on Sheldon Brown

Shimano Nexus SG-7C21 7-Speed with Coaster Brake

Factory lack of lube!

Proper pawl oiling with Phil Wood Tenacious Oil

Greased and oiled!

Shimano Nexus SG-7R46 7-Speed Axle Assembly
If you have taken yours appart or it came appart as it often does during an overhaul, then, fear not!
There are instructions on the Sheldon Brown website.
http://sheldonbrown.com/nexus-7-axle.html

Shimano SG-4R31 4 Speed

Shimano Nexus SG-3R40 3Speed

Shimano 3CC Three Speed Coaster Brake

Shimano 3SC Three Speed Coaster Brake

Shimano SG-3S20 Three Speed

Shimano Roller Brake.
We can even service so called non-serviceable bike parts! 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.

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...

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...

Shimano Nexus 3 Speed Hub Manual Download

... 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.

Shimano Nexus 3 Speed Wheel

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.