[Flicker]

This bike is special to me because it is the same model as I bought new when I was 18.
I rode that first one to work and some cross country and didn’t really maintain it all that well

Eventually I blew the gearbox out and the dealers had no stock of parts, and they didn’t think they would have them anytime soon.
I later learned that there was a quality problem with the heat treat of the gears and I was only partially to blame.
Canada’s only a stone’s throw from here and they had the parts I needed so I rebuilt the gearbox

That was a real shot in the arm for me because that totally confusing mass of gears forced me to think it through and understand how a transmission works. When I buttoned it up and it actually worked I was on cloud nine. I carried that learned patience and mechanical confidence with me the rest of my life and it served me well in my trade as a machinist and machine design shop owner.

Eventually life moved on and I sold the bike. I think I’m pretty lucky to have found this one
I also bought a 72 T100R in pieces from the same guy and hung that one together first.
So this one sat for awhile but I’m going to do my best to do right by it.

 

[Flicker]

So what are my objectives?
Well, first off I want to keep it original. It’s still even got the Bob Leppan dealership stickers on it.
I just want to ride it. This frame handles really well in my opinion.

I want it original because that’s how I want it. I don’t plan on selling it.
It’s only got about 5000 miles. It came with original factory rubber, etc.
Paint is in remarkably good shape. Good compression.
There’s a welded exhaust pipe and dented (and fractured) chaincase where apparently it had come in contact with an immovable object.
Looks like foot peg hammered its way in. Mufflers are dented here and there.
Electrical looks decent but harness looks aged.

So I bought NOS pipes, mufflers, chaincase, harness, sprockets.
New hoses and wheel bearings. New Dunlop K70 tires.
By the way, I really appreciate having Mitch Klempf’s advice, parts, and quick service as a resource.

 

[Flicker]

Noticed the woodruff key was missing from the clutch hub when I pulled it to install the new gearbox sprocket.
Taper on mainshaft was galled as was hub ID taper. 19 rollers instead of 20.

Delicately removed gall marks and re-installed clutch.
It wobbled. Like a lot. Removed clutch.
Put an indicator on mainshaft taper and indeed it has significant runout.

So mainshaft was bent, probably by footpeg smacking into case, case into clutch.
Accident was probably why this bike was shelved after 5000 miles. Hope nobody was hurt.

So gearbox comes apart.
In the meantime I put the rear wheel back together.

 

[Flicker]

I prepped myself by reading the workshop manual and everything else I've got.
Then watched Hughie Hancox 650 Unit DVD set. What a wonderful resource that is.
That guy is an artist, both as a mechanic and author.
Gutted the gearbox and sure enough the mainshaft is bent .010"

 

[Flicker]

This gear box has been opened before judging by the RTV and stripped screw heads
Checked the width of Layshaft 5th gear and it is 11/16 so indeed I have the old gear set.

 

[Flicker]

Triumph service bulletin from 1975 says I need a bunch of other goodies for improvements made
I'll put in all new bushes, bearings, and seals too.
The bronze bushing lined gears are sloppy on their shafts.
That .010" whip in the mainshaft had to go somewhere and it would explain the orange sediment om the floor of the casing.

 

[Flicker]

Assessed gear situation and decided to buy a full new set and got them and everything else on order.
Gears were in good shape but have been superseded by safer ones.
Also, bushings were all worn and the amount of effort to re-line each gear would not be insignificant.

April 21 and it snowed 2 days ago but today it's 60 and windy as hell
Took the Thunderbird out for inaugural ride with the new windshield and no problems with the wind
I love it. 60 feels like 40MPH and I don't think it detracts from the look

 

[Flicker]

Cleaning things up I noticed that the gearbox inner and outer covers were each located by one hollow dowel
Could be root cause or contributor to maladies as bearing bores could be misaligned by as much slop as is in the bolt clearance holes.
Bearings, as we all know, really prefer to be concentric.
Added (4) of 57-0989 hollow dowels to my parts order.

 

[Flicker]

Removed studs so I can get mounting faces clean and flat
Found this slick stud removal tool. I honestly didn’t know they existed.
https://www.amazon.com/gp/product/B01GKEBG9I

Cleaned and deburred sharp edges of machined face. I hate sharp edges except on knives.
Blew out threads and a whole bunch more bronze residue plastered itself inside casing.
Inner cover thrust washer dowel was sheared off and you can see where it gouged its way to oblivion.

I’ll be drilling and reaming for a new dowel so I removed quadrant and leaf spring.
Finished the day off with a luxurious kerosene bath. Tomorrow the bearings come out.

If anybody has advice or criticism I'm wide open. Learned a long time ago I don't know everything.
When I find out I'm wrong about something I consider it a win because now I know the truth.

 

[Flicker]

Decided to use the existing bronze thrust washer as a guide to put in the new dowel hole
So I’ll leave the needle roller bearing in to serve as a locating device for thrust washer.
Bolted through the thrust washer and roller bearing to hold it in place.

Hole in thrust washer is .136” so I will use a #29 drill to spot the location before switching to a .110” drill to depth, then a .120” drill to leave .005” to ream.
The trick is to sneak up on the size (.1245”) you want and not scare it away.
Also, reamers will always cut oversize (how much depends on a few factors) so I need a .1240” reamer so my 1/8 dowel will be a press fit.

Surprisingly, I was able to find a 10 pack of 1/8 x 3/8 dowels, a 12 pack of #29 drills, and a .1240” reamer all on Amazon and delivered tomorrow.
That #29 gets used a lot for #8-32 and M4 tap drills.

I have an old drill press I got off Craigslist and it’s got a crappy Chinese drill chuck. I indicated the runout at the base of the drill and it was .014”.
Basically it’s a spirograph. I knocked the chuck out of the taper and put an indicator up in the taper and it’s bang on zero. So… good spindle, bad chuck.

Bought a new Jacobs chuck and it should enable me to hold the tolerance I need.
Hah. The good quality new chuck cost more than the drill press, but now I won’t be muttering every time I drill a hole.

Faulkner quote of the day (and this one's a beauty)
Clocks slay time... time is dead as long as it is being clicked off by little wheels; only when the clock stops does time come to life.

 

[Flicker]

New gear set, bearings, and seals arrived.
Also bought the bottom-up plunger detent assembly for the camplate.
I’ll reverse engineer a fixture to drill my case for that.
Only thing holding the engine in the frame right now is about 4 bolts so I’ll take it out to where I can get to it to drill it.
I hear mixed opinions with regard to leaf spring detent vs. plunger but I was talked into it by somebody I trust.

Seest thou a man wise in his own conceit? there is more hope of a fool than of him.
Proverbs 26:12

 

[Flicker]

Put the old mainshaft in a vise and set up the clutch hub and bearings and gave the chainwheel a spin.
It indicates .008” axial runout, so I’m calling it trash.
Bought two new ones manufactured in England and they should be here in about a week

My 72 Daytona takes the same part #57-1570 and it’s become a little dicey when downshifting
When those 8 broached slots get notched and ragged, the plates have trouble freeing up.

 

[Flicker]

New bushings and seals came in for kickstart and shifter.
Water had laid in it, so along with RTV and Permatex, it was pretty nasty
Archeological evidence shows me as the third one to take this apart since new
Cleaned it up and put it back together

 

[Flicker]

Made myself a drill jig for installing a spring plunger for my camplate detent

 

[Flicker]

Built up my new gearset a few times to set the process in my mind and buttoned it up.
With all new bushings and dowels in the inner and outer covers, shifter return springs weren’t working very well.
I put a .005” oversize bushing for the quadrant shaft in the inner cover and also a gasket between inner and outer covers and the return springs freed up (although a little stiff). I’m banking on it wearing in with use. If not, I’ll open that quadrant shaft bushing up another .001”

 

[Flicker]

New inner and outer clutch, engine sprocket and primary chain
Never did clutch rubbers before. That taxed all the capability of my bench vise but I got them in
Notice I forgot the clutch spring studs?
This primary was a treat compared to my 500, on which you have to pass the stator through the chain as you mount the clutch/engine sprocket/chain.

Took that poor carburetter off and the mount flange was warped .015” and the bore was .005” out of round.
Somebody tightened it all the way down over a fat O-ring, which came out looking like a hollow pancake.
Truth be told, I once holed a piston because those carb bolts came loose so I understand the temptation.
I know there is a carb body straightening jig that can be made and maybe someday I’ll make one but for now I decided to shell out the $300 for a new Amal Premier so it’s on its way

 

[Flicker]

New pipes and mufflers installed. Old ones were pretty battered.
I must say the original clamps are of a much higher quality than the new ones, so I cleaned them up and put them back on
Heard somebody once say those big megaphones are about as stylish as long sideburns.
When I was a kid, I took mine off and put on straight TT’s. It made me badass if only in my own mind, but that was apparently enough

 

[Flicker]

And now, because this thread has been relegated to the remote corners of TrimphRat where hardly anybody looks at it, and because I feel like it, it's time for a musical interlude
(1482) The Long Ryders - "Looking for Lewis and Clark" (official promo video) - YouTube
It needs to be cranked up for proper effect.

 

[Flicker]

Okay kids, we’re on the home stretch, it is OFF THE LIFT
To be honest, that bike sat there for years while I did another bike and rode yet another and bought a 30’ sailboat and figured out that the reason I was always injured was because sailing’s a brutal sport.
Took it out in the yard for a quick bath, then took off the tank and carb and got busy cleaning up under there.
Torqued the head and rocker box bolts, set my tappets to .004 and .006, checked compression to be ~140 both sides.

 

[GrandPaulZ]

You forgot about the part that says "...and then it fired up on the first kick!"