Friday, April 8, 2016

Gear Box Rebuild Part II


I thought the gearbox would be pretty straightforward, I would post a few pics and not have much to say about it. I found there are several things in the RE gearbox, made by Albion, worth noting and I have detailed them in the following post. 

After everything was taken apart it was cleaned and inspected to determine what could be reused Vs replaced. The S2 only had 10k miles on it and everything looked pretty good. New ball bearings were ordered along with all of the seals and sealing washers. My friends on the Royal Enfield Interceptor Yahoo group told me about a great 5 part tech series on the Albion gearbox by Don Morley. This is located on "Hitchcocks Motorcycle" website in their "Technical Notes" page. It is a must read for an Albion rebuild. Great history is covered too......a lathe gearbox....who knew?

A good read for an Albion re-builder. 

Through this article I learned several key things. The layshaft bushings leave the factory with a +.001 spec on the diameter. There is no "out of service" spec given that I could find but the manual says to replace the bushings when movement of the shaft is excessive. What is excessive? A member of the RE group told me that +.0045 is a spec used on other brit bikes for a reference. Mine measured +.01 which sounds excessive but movement of the shaft was minimal so I decided to keep them as is. If the box is noisy I will replace them and consider it a learning experience.


The cases were cleaned via soda blasting. I like this method as water removes all the grit when finished. It also removes minimal material keeping the finish close to original. Screw heads were hammered and filed back into shape and cases buffed to where they were when they left factory in June of 1969. Threaded holes were chased with taps.

All parts cleaned and ready to go. Looks like a lot of parts compared to my BSA's.

The gearset cleaned, inspected, oiled and ready to go back in its place.

A couple of noteworthy points to make at this step. There are two gears that are very similar and cannot be interchanged. One is on the layshaft and one on the mainshaft. This is discussed in the Albion gearbox article mentioned above. The second point regards the oil thrower washers. They must be installed with recesses facing away from the bearing they surround. One was correct on mine and one was backward. Corrected and on we go. 

New bearings and a "heavy service two way seal" installed in place of the standard single lip seal. It has a metal casing and heavier rubber sealing lip. I have not used these before but it looks like it may be a good option. 

Assembled and ready for the outer cover.

I did not find the Albion tech article until after I disassembled my gearbox. If I had I would have marked my shifter plate location before removing it. Bummer for me. I found a method to set this up on the web. The pivot arm must be centered to the plate attachment fittings (mounts with thin nuts). If things do not shift I will revisit this setup. Another area to watch is the gear operator plunger. If this is too tight it will cause stiff gear changes. Too loose and it will pop out of gear. It must be aligned properly too.

Everything reassembled and moving through the gears well. Neutral finder works too. Time to put it on the shelf until the rest of the bike catches up.


A controversial topic to dive into is which oil to use. There are many good points made in support of various positions. I have used Valvoline 75/90 Full Synthetic gear oil on my brit bikes for years and will continue to do so. Study the topic and take your positions.....proceed at your own risk.... 

Fall 2018 Update:  

My plan with the Interceptor was to show it during the summer it was finished and then take it riding. After placing 2nd in the Masters Class of West Michigan's largest motorcycle show in June it was put on ice for the summer. Michigan's second largest Antique motorcycle show is the "Battle of the Brits" on the east side of the state and held in September. At this show the Interceptor was lucky enough to win the "Masters Class" first place "Best of Show". A good summer for the RE SII. Now it was time to take it out and put a few miles on it as planned. 

The gearbox did not shift well during its initial rides although rocking it through the pattern at a standstill seemed fine. Adjusting the detent plunger out two turns and making its screw slot parallel to the ground improved the situation. Down shifting was still problematic. Two additional turns out of the plunger put this situation right and shifting of the RE is pretty good now. 

The Albion is a querky gearbox. Do not expect Norton or BSA performance with it. It takes a deliberate stab to make it go up or down. I have learned to feel when it has moved its position - after a hundred miles of riding back roads. Downshifting before the RPM's drop does not always work either. I also find it easy to hit neutral between 3rd and 4th gears, especially shifting down. There may be more tweaking on the Albion to hit its potential but I am satisfied with its performance as long as I concentrate on making it work properly. Overall performance of the Interceptor is great and it is an enjoyable machine to ride, even with the off-road handlebars. Substantial power all through the rev range with minimal vibration are unique in my Brit bike riding experiences. The SII is a real keeper I think. 


Fall 2020 Update - more adjusting:

The year of Covid 19 and social distancing has been perfect for a biker. I have logged more miles in 2020 than in any year since the early 80's which was before I was married and had kids. All miles are within a day of home - no overnighters in the land of Covid for this guy.

My Albion was working alright but not as smoothly as I thought it should be. It was easy to push through 3rd gear and it popped out of the others on occasion. I found info for adjusting newer RE Albions which worked well on my SII. To cure popping out of gear I tightened the detent plunger. I did this in steps until I was satisfied with its feel. I turned the plunger until it was difficult to shift and then back out a turn. What works on a cold gearbox in your shop may not be the same as when it is warmed up and going down the road. (That was my experience.) Remember to keep the plunger screw slot parallel to the ground.

The issue of going through 3rd was fixed by adjusting the ratchet plate. I originally set mine up with the outer plate centered on its locking pins. To get a solid engagement I rotated the plate 1/8-inch counterclockwise. This caused the opposite problem as it was now difficult to shift into gear. Rotating the plate back half way for a net counterclockwise move of 1/16 of an inch put the plate in its correct position as shifting is quite good with these adjustments. 

If you want your Albion to shift well get acquainted with this assembly. 

There is a technique to shifting the Albion. Going into 2nd through 4th you will feel two shift dog clicks as they disengage and engage. If you let pressure off of the shifter after one click you will be in a false neutral. When you feel the second click keep pressure on the shift lever until the clutch is out. This will stop it from popping out of gear. Downshifting has a technique too.....

Before downshifting drop the RPM's low or it will be difficult to make the shift. Another option is to blip the throttle to get the lower gear spinning faster to aid in engagement with the higher gear. The RE pulls so well at lower speeds I avoid most of the downshifting I would find necessary on my BSA or Nortons. The neutral finder also works well. I use it exclusively for downshifting to neutral when I come to a stop. You must almost be stopped to engage it. I have also moved to a different gear oil...... 

The Harley guys like full synthetic 75/140 which I have put in the RE. It seems to cushion the gears better and reduce noise. Hopefully it will make it easier for the housing to contain it as well. I do not know anyone else using this oil in their Albion. Proceed at your own risk....

Maybe the Albion is not the most user-friendly unit, but I have found the few adjustments noted above make the RE a very enjoyable machine to ride. Who buys an SII for the same experience they can get on those other brands?  Not me for sure. Time to log more miles.....

Heavier than specked but working well....so far....

Albion rebuild part one.....

2 comments:

  1. Can the "heavy service two way seal" oil seal for the be installed with the gearbox on the bike? Primary off and sprocket off?

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    1. I do not have much experience with them but mine has been working for 500 miles in its current location with no issues. I would consult the source you are getting the seal from as they deal with people who use them every day for various applications.

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