The transmission of my Indian Scout motorcycle is now back on the frame and the gearbox overhaul is a complete success! OK, I’m so excited, I’m rushing ahead by telling you this!
Soooo much has happened in the last month or so, it’s hard for me to contain, but let’s back up a little!
A bit of background
First I suppose that you know what I’m talking about here. The crazy project I’m working on with my dad: the complete restoration of the Indian Scout 741 motorcycle he bought when he was young. The one that will take me on new adventures soon.
I can now say ‘complete‘ restoration because of what happened last month and because of where we stand now…
Second, you may recall that we took the gearbox apart. It feels to me like it was ages ago but it was just a few months back, really. Things weren’t a complete disaster inside, as only a few things had to be handled. It took a while for my brother to repair the countershaft gear cluster and the longer it took, the more worried I was, but now it’s all good.
One funny thing is that, when I wrote the gearbox overhaul part 1 article, I had anticipated a “multiple part series full of mysteries, annoyance, tears and fears but with a joyful ending“. And you know what? I got just that!! But for you, I’ll cut to the chase and tell you all in this part 2 and final piece about the transmission.
So, what happened next?
My brother brilliantly repaired the damaged teeth of the countershaft gear cluster, the ‘Christmas tree’ as it is called. He also repaired the teeth of the gear slider. Hopefully such repairs will last, will see.
*****
Update:
I finally managed to corner my brother so he could explain the repairs on the Christmas tree teeth. He did this in the factory he works at, with professional materials and tools. He had done so previously & successfully on another gearbox.
He used the products from a brand called Castolin and what seems to be called plasma welding. He said he used rods called Castotig 5 but the numbers on the website are longer, so I’m not sure which one it was. The rods are made of a special alloy and have a hardness of 55HRC which apparently is really hard! So hard that to rectify and finish the work done, it also requires special tools. There is no follow up heat treatment as the rods are already treated or something…
Sorry, this is the best I can do! I didn’t understand everything he said, it was very technical. And now I’m even more glad than before that he was the one to handle this issue!
*****
However there was now an issue with the Christmas tree (I love this Christmas tree thing!) bushing 🙁
The thrust washer conundrum
You may recall that a washer felt, when we pulled the main shaft. Well that was just the beginning of the story. At the time I had no clue what this washer was. Ah ah! That’s quite funny actually to me, now. Maybe I am learning a thing or 2, after all!
This washer was actually ‘hiding’ a much bigger issue. You see (well you already know this) this simple looking washer is a thrust washer. It is there, amongst other things, to prevent movement of the shaft along the axis (something like that, not sure how to explain). It is actually of major importance for the appropriate functioning of the gearbox. But it shouldn’t have been alone! Clearly the main shaft had way too much end-play and the reason was that there should have been at least one other thrust washer.
This was obviously explained to me. I didn’t come up with it from thin air. And you can clearly see such trust washers on this diagram (nb 19-28).
So I tried to explain to my dad but with time, this thrust washer issue became a highly confrontational topic and I didn’t know how we were going to sort it out, considering his reaction.
The bushing issue
The countershaft gear cluster was brilliantly repaired but one of the bushing was now pushed inside which wasn’t good.
As you may guess by now, my dad dismissed this and yes he rebuilt the gearbox and yes I let him… temporarily!
Dealing with my dad
I know my dad rebuilt his bike once before, after it had spent over 30 years, almost completely dismantled and in boxes. It’s impressive! Especially considering, he did not have any instruction manual, not even a single picture, at the time. Very impressive indeed!
In addition, I know my mechanical knowledges are a lightyear away from his.
Finally, I also know the engine was in one piece when he rebuilt it. He had never took the transmission apart. So I know he didn’t loose the thrust washer. I’m in no way blaming him for its disappearance. It was probably never there, in the first place, or at least since the bike was demilitarized.
But again, I’m not making things up, I do a lot of research, I study and I get help. I’m certainly not trying to find issues where there aren’t any. Although sometimes I feel that’s what he may be thinking.
When I try to explain that the end-play of the main shaft is too important and explain the issues it can create on both sides, I probably don’t do a fantastic job. But he certainly does a great job resisting to see the issues and pretending to not understand. I don’t get it, especially when I show him the diagrams and other sources.
Why such resistance? That, I’ll probably never understand.
So we had all the pieces to put the gearbox back together for 2 months or so. I let him (temporarily!) put it all back together but I nervously waited and waited to find a way to make him accept to deal with the main shaft end play issue and the bushing issue…
Click on the image below to see the gears in action!
And then…
The answer came!
If you read my last update, you know I had finally found someone to handle the valve seats and valve guides. Not just anyone, an Indian motorcycle professional!
You also know he came to see my dad and left with most of the engine. That bit was a shock to me. I freaked out completely!
Well… a month later, we got to spend 2 days with him and rebuilt the engine (yes I’ll tell you all about this soon!) and the gearbox of course! It was amazing.
The absolutely hilarious part was when he explained to my dad, what was to be done on the gearbox and showed him the issues that the main shaft end-play could create, if not sorted.
When my dad acknowledged silently that I had explained the same, the look and smile on my dad’s face were everything to me!
It took 2 months, several confrontations and a lot of frustration to get there. When I explained, he always rejected my explanations. When this guy, yes a professional, explained, he agreed.
I could have felt defeated. It weirdly felt like I had won a battle. A small battle where maybe he recognized I wasn’t talking nonsense and that I was indeed learning my shit!
But the war isn’t about being right or wrong. It’s about getting the bike in tip top shape. And it seems that by now, I don’t need approval from anyone anymore, I don’t need anyone’s recognition of my motivation, of the work already done, of my dedication.
I don’t know. It’s probably a little bit of different things, because I guess I’ll always need my daddy’s approval 😉
The work in progress
Since the transmission was already apart, it was decided to change the ball bearings. Heat the case, freeze the ball bearing and remove. Sounds simple but these are things I won’t do. I’m not comfortable with a blowtorch, at all!
But it’s done now so it should last a few decades. Hopefully.
Since everything else was ready, bushing included, it was time to put everything back together. The right side where the kick starter is comes first, then the Christmas tree, and last the gear slider with its fork.
This time, I did manage to put it in and remove it. A little practice and it all worked out! You need to read part 1 to understand that bit…
The thrust washers were put in. Tested, bored a little, tested, bored again… all good.
At this point it seems easy but the reality is that it only feels easy because I had disassembled and reassembled the transmission several times before. And most importantly because it was done and supervised by a professional.
No matter how much I would have tried at home, I don’t think I would have gotten the same result. Or at least not the same confidence in the result.
Now if I need to do this again, things will be different!!
When we got home, we removed the inner primary cover to attach the transmission to the frame. We tested the gears and I took more and more pictures!
And this it is! The transmission overhaul of my bike is done. It’s been overall a highly annoying process (!) but the end result is great, so I’ll forget about the struggles and just cross this off my list!
Now, you can read about the rest of the engine overhaul and you’ll see my implication was far from brilliant…
Pin this for later
Great story so far. Wondering if you would be able to provide me with details on what your brother did to fix the Christmas tree. That is what welder name, what rod or welding medium? Also how did he go about heat treating it to retain its strength?
Thanks so much
Hi & thanks! I do not know exactly how my brother did it. I’m going back to see my dad this week end so I will try to find out.
The pro who worked on the engine doesn’t usually recommend to do this as it might not hold. We’ll see!
This is a great article and you are banged on with your points about Indian scout 741 gearbox overhaul part2. Be clear about what you really need and want to accomplish at this point- you are right with this point and please write more in future.
Thank you! It means a lot to me that my Indian stories are appreciated, even if by just a few!
Confinement means no work on the bike, so I’ll have to wait a bit longer to ride it… 🙁