Trans rebuild

Pointers for trans repair to get smooth, leakfree result.

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Excalibur
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Trans rebuild

#1

Post by Excalibur »

As promised here is some pics after dismantling. It took a bit of time because I had to modify my sprocket tube socket, fab a gearbox bracket and fab a kicker ratchet puller.

Gearbox bracket to hold in vise
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Parts look in really good order..
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"Andrews" marking..
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Good condition
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Yet to wash up, clean and prep.
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Have been doing quite a bit of research including watching the 3.5hr Lowbrow video, reading various threads in the Knowledge Base and elsewhere.

Plan:
Seal the mounting studs as per Lowbrow video.
Seal high gear spline, yet to be determined.
Polish selector, rachet, dent parts.
Renew 35337-36 retaining ring on mainshaft.

Thoughts:
I want to take the opportunity to consider anything that could sweeten the gear shifting, especially upshifting into 2nd. The most effective thing I've done to improve it was to improve clutch operation. Now's the time if there's anything inside that might help.

Questions:
According to Lowbrow video, polishing of the detent plunger was worth doing. Is consideration of the shape of the point worth looking at or was Lowbrow only shining up any rust or roughness? Other ideas?

The drive sprocket fit to spline is very slightly loose. The nut was not loose. Is there anything to help here?

Any other pointers that might help?

More pics available. Getting set to post all pics on my Blog for permanent reference.

Comments please. Keen to discuss, consider, etc. Thanks.



Excalibur
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Re: Trans rebuild

#2

Post by Excalibur »

Made time today to do some more.

Got the parts cleaned and dressed up.

The little "L" key for the spline is missing. I can make this else the local Harley guy might have one. Seems to me, this key is only going to come into play if the big nut comes loose.

The shifter drum has +.003 excess endplay above maximum. Not got the drum out yet but it seems simple enough to sort out a regular shim washer.

The countershaft has +.004 excess endplay above maximum. Calculating, I need .095" or .100" washer which will give .012" or .007" endplay respectively. Hoping I can get a washer otherwise if it came down to it, I could make it from mild steel then harden.

The 35337-36 wasn't available from the dealer, now looking at plan B (trying elsewhere locally). According to my local HD shop one company was doing a spirolox ring at one time, now no longer available.? He thought these were an improvement. Then the story of how the gear could slide along and engage two gears at once then cases can blow apart. :shock:

Am learning heaps
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awander
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Re: Trans rebuild

#3

Post by awander »

You're correct that the small key that fits in the spline does nothing once it's all tightened up. If the spacer slips with the sprocket nut tight, I think you've got big problems with your parts.

I don't know what they put that in there for, and I think it was omitted in later transmissions.

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Re: Trans rebuild

#4

Post by Raytag »

Timing is just right :P Pls keep posting plenty cause I may need this soon
Excalibur wrote:
Fri May 22, 2020 9:01 am
...
The 35337-36 wasn't available from the dealer, now looking at plan B (trying elsewhere locally). ...
Google spits out: Century Springs in Auckland manufacturing rings like that. Guess they won`t sell to private customer unless you order 10.000 units but perhaps let you know whom they`re dealing with? Point is that such customer should have grinding machines (horizontal/cup/tool grinder). They just put it on the magnetic table, switch on the coolant and let the grinding wheel spin. It`s a matter of a few minutes to achieve the exact thickness you need so the tip shouldn`t be too big

Ray

Excalibur
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Re: Trans rebuild

#5

Post by Excalibur »

Thanks for the comments.

I have a 35337-36 coming from a local supplier.

The man says there is a box of countershaft washers at my hometown Harley shop. Just need to measure them and we'll see.

Little bit of zinc plating on some of the parts just to tidy them up. Am doing a multi-step process, plate, hand polish, plate again. Seems to work well.

Almost done grooming the parts.

Question: I bought some sealer to coat the seals as Lowbrow does. I notice the big seal has a thin blue coating (James Gaskets type). Isn't this meant to seal the outer ? But the housing has had a bit of a hiding where the seal fits. Looks like a screw driver has been hammered in, in a previous life.

Thanks for any thoughts.

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Re: Trans rebuild

#6

Post by Frankenstein »

Consider the closer ratio 2.6:1 first gear to improve the 1-2 shift. the great differential in gear rotation on stock 1st and 2nd contributes greatly to the "klunk".
DD

Excalibur
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Re: Trans rebuild

#7

Post by Excalibur »

Thanks Franky for the helpful idea. I can see how a different ratio would have an effect.

I may be wrong but the problem doesn't seem to be to do with a klunk but rather the amount of effort required by the foot. 1>2 shift is noticeably more force required compared to 2>3 and 3>4. When shifting, my heel has to leave the footboard so I lose advantage of any leverage from it. More or less the action is a rigid-leg kick up. Shifting down is no issue. I have a few ideas to try so we'll see.

Making some good progress.
1/. Spring behind the shifter gear was out of shape and worn thin.
2/. Polished and groomed the shifter parts of roughness, sharp edges and rust.
3/. Sealed the mounting stud holes from the inside.
4/. Deburred and groomed the gasket surfaces
5/. Shimmed the shifter drum endplay (.001").
6/. Fitted main drive gear.
7/. Finished plating the screws, shifter lever etc.
8/. The top is fully assembled and ready to go.

So all clean and ready for the circlip and countershaft washer. Courier was supposed to be delivering today.

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Re: Trans rebuild

#8

Post by RooDog »

Does it shift any better without the clutch? Applying pressure to the shifter and quickly backing off the throttle should allow a fast an smooth up shift to the next gear. Racers do this all the time....
....RooDog....

Excalibur
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Re: Trans rebuild

#9

Post by Excalibur »

RooDog wrote:
Wed May 27, 2020 12:44 pm
Does it shift any better without the clutch? Applying pressure to the shifter and quickly backing off the throttle should allow a fast an smooth up shift to the next gear. Racers do this all the time....
....RooDog....
Thanks.
Am very familiar with the technique. I own a number of bikes where I've used it including 2 competition bikes. All of these are '70's 5-speed Triumphs.
To clarify, for the technique to work nicely as a quick shift, the throttle needs to go from full open- to full closed- to full open... and all within the space of a fraction second or so. Effectively as fast as you can fully close and fully open the throttle, the shift can be made. The Triumph 5-speed lends itself extremely well to the technique but a Harley 4-speed doesn't or at least in my experience drag racing my Shovel around c1990. I recall there was a definite limit to how much the shift could be "hurried" and I elected to clutch all the shifts as well. I won a trophy racing that Shovel in DYO drags so it says something for consistency.

Just got word, the circlip has arrived so am heading across town to get it shortly.

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Re: Trans rebuild

#10

Post by RooDog »

An ignition interrupt, or kill button, had the same effect without having to coordinate the throttle....

But the point of this exercise is if the tranny shifts well with this method, the the fault is not in the gear box and is more likely due to the clutch not releasing cleanly....
Also, I have used this method on the street, full power, full throttle is not necessary, simply backing off the throttle while pulling will unload the gears enough to make the change, and you may roll back into it as much as you please 'til your ready for another gear change..... Like double clutching a non-syncro truck tranny, it's just a matter of matching gear speeds within the gear box......
....RooDog....

Excalibur
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Re: Trans rebuild

#11

Post by Excalibur »

It's a good thought. I like the thinking.

It's as you say... with my Indian 741 3-speed crash box, you can feel the ideal point of engagement. At least half of the upshifts from 2>3 are clutchless on that. It has a long, hand gearlever on the right side of tank. The Pan is quite the opposite in that there's perhaps poorer and awkward leverage so that doesn't allow opportunity to have proper feel?

Both of the shafts are installed now but I might not be able to do much more before Sunday.

By the way, Post is still snarled up here with big delays. Something I bought 1st March from abroad still hasn't shown up. How's it over your way since Covid? Pondering about when I can proceed to buy the replacement kicker cover from US?

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Re: Trans rebuild

#12

Post by Raytag »

Standard stuff (acc to websites available) works almost as usual maybe one day more. Any sort of materials within the EU takes longer one week or so cause of shortage of truckies (cheap east european truckies wern`t able to leave their homecountries) and countries within the EU are just opening borders again. Overseas stuff is hardly available if at all . Some steel manufacturing is grinding to a halt right now :!: It`s basically like this: The industrial supply chain via ship is broken. Acc to https://www.flightradar24.com the traffic just begins to pickup again. Many planes are private charter ... Last week that website almost showed nothing at all.

Ray

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Re: Trans rebuild

#13

Post by Frankenstein »

If you'll reflect for a moment, you'll see that the same mechanisms are at play in all 3 shifting intervals. However, because of the much greater differentials in gear speed rotation in the 1st-2nd shift, your foot pressure is being used to slow down, via the shift dog, the mating rotating parts 'till their speeds match and allow engagement of the dog. Thus the close ratio gears will improve the shift by reducing the rotation speed differential. The ratchet top shift mechanism doesn't actually mechanically force the dog into engagement, it only pushes the dog in the right direction and waits for a speed match to allow spring pressure to finish the engagement process.
At least, that's my understanding of the foot shift operation. personally, I use the hand shift lid with a jockey handle and get positive gear engagement :D :D
DD

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