moving on...1978 T140 hard shifting

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I just got a 1978 T140 Bonneville up and running since it lay idle for years. It is doing well except for stiff shifting and impossible to find neutral at a stop sign. I do not know what it was like before. I put in new fiber plates.
Shifts on the left side.
Carbs are synchronized.
Any ideas?
 

acadian

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I'm unfamiliar with LH shift T140's, but have you inspected the ball/ramp mechanism in the tranny cover?
 
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I haven't done anything yet, looking for ideas. First, I will run some Tri-Flow down the cable.
 

Fast Eddie

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New fibre plates? Are they from a trusted manufacturer and supplier? You wouldn’t be the first to be hampered by crappy pattern parts!

Tight primary chain can definitely cause this.

As can shit / degraded gearbox oil.

Lack of clutch lift is another prime suspect, check its adjusted properly (ensure cable is slack, then adjust clutch centre nut, then adjust cable), if the lifter mechanism is partially lifted by the cable before adjusting the clutch centre nut, you’ll loose lift, and get drag.

But possibly the most common reason on a Triumph is a pressure plate that is not lifting and seating perfectly square. This will cause both slip and drag.

And another possible cause is the cam plate plunger area. I’ve seen them where the housing fouls the cam plate because it’s screwed in too far. Also sometimes there is just too much pressure from the plunger and spring acting on the cam plate and fitting an extra washer or two to space it off helps tremendously. There are different types of plunger too, pointy vs rounded. Experimenting with different types can help. There are plungers available with a captured ball in the end which look like a really good idea but they’re NOT. They allow the cam plate to foul the none ball part of the plunger and just don’t work.

A 5 speed Triumph box is just about as sweet as a box gets when set up right, so if it’s not shifting nicely, something is wrong.

However... it is certainly not uncommon for them to be difficult to get into neutral at a standstill, you might be chasing a unicorn with that one !

I found Bel Ray made mine far smoother shifting than Shockproof oil BTW.
 
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Mr. Comstock recommends ATF in the Norton gear box, every try it in a Triumph?
There is a poor feel in the handlebar lever so that is my first target.
 

Esmerela

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I just got a 1978 T140 Bonneville up and running since it lay idle for years. It is doing well except for stiff shifting and impossible to find neutral at a stop sign. I do not know what it was like before. I put in new fiber plates.
Shifts on the left side.
Carbs are synchronized.
Any ideas?
When you fitted the new plates did you take time to check the run-out on the pressure plate ? you can correct the run-out by adjusting the the load on the springs.
 
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I got the pressure plate to lift as squarely as possible. The clutch lever is stiff..I oiled the cable and ran it with as few turns as possible. The clutch nuts are flush with the threaded post, I will back them off a bit and see what happens. Plates are barnett.
 
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First I will go after the clutch lever action. It is difficult to pull and almost impossible to make the lever reach the grip
 

Fast Eddie

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T140 clutches are always a hard pull compared to any normal bike. Be careful backing those screws out too far as you may cause clutch slip, which you won’t discover till you ride it, and further adjustment necessitates removal of the primary cover... not the most intelligent design (kinda why I put a hydraulic clutch on mine, the screws are in to a point the lever would be just horrible with a cable, but I’m guaranteed a slip free / drag free clutch). As a rule, if it’s all stock stuff, if you don’t need a notched screwdriver then the screw heads are not in far enough. But you don’t know if someone put in shorter studs or longer springs or etc!

I believe a featherlight clutch cable is a must. You should have NO cable ties on the cable at all, if it’s routed through the inner of the tank it can’t go anywhere and thus needs no ties. And route it with the largest, smoothest bends that you can. I sometimes fit and re-fit cables half a dozen times until I’m happy, fussy perhaps, but it pays off.
 
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I know that for me the pointy end shift indexer was better. I also took a look at the shift quadrant to make sure the edge
where the indexer goes was smooth. You can reduce the spring load against the pointy bit by adding washers.

Fact is ALL of the suggestions need to be applied!
 

Fast Eddie

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Yes I ended up with a pointy plunger working best in mine, kinda counter intuitive I thought. I also spaced it out a little more with and extra washer.
 

L.A.B.

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First I will go after the clutch lever action. It is difficult to pull and almost impossible to make the lever reach the grip
Sounds like the springs are going coil-bound. It hasn't got a 1-1/16" pivot radius clutch lever assembly (instead of 7/8") by any chance?
 
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a 78 T140 lives at my house it belongs to a pal it shifts great but finding neutral when hot at a stop is near impossible my 75 XS650 is the same way I quit obsessing over it a long time ago
 

L.A.B.

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Mr. Comstock recommends ATF in the Norton gear box, every try it in a Triumph?
There is a poor feel in the handlebar lever so that is my first target.
The crankcase and primary compartments are connected as the engine breathes through the primary case so don't put ATF in the primary as it will contaminate the engine oil and I see no reason to use ATF in the gearbox.
 
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Fast Eddie

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+1 on what LAB sez...

This is why Triumphs of this era should only use engine oil that is suitable for wet clutches.
 
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we use 20/50 vulvalean motorsickel oil in this bike and my 72 bonnie as well however I am having good success in primary with type F autotrans fluid in my commando and 68 A65 and 72 A65T
 

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