[DrPat]

Hi everyone, just thought I'd ask if anyone has a you-beaut trick to seal the alternator wire hole in the back of the primary chaincase. I'm just about to replace my stator (long saga... sigh...), and this is a pernicious leak, I've found, in all of my Meriden machines (and is the only one from this particular specimen I have at the moment)

I've got the grommet, and the boot coming, and know about the trick of cutting a nick out of the gasket by the wire; just wondered if anyone else had any thoughts?

Of course, I could always put a giant, cricket ball sized, gob of silicon around the whole area and challenge the bloody thing to leak... or just not put any oil in the chaincase; but while these solutions would satisfy some maniac part of me, and I could treat it as revenge on all the Triumphs I've wrestled with in the last 50 years, part of me suspects there is a better way...

all the best from the Antipodes - Pat

 

[TR7RVMan]

Hi DrPat, On paper the inner boot is supposed to be the main seal to stop leaks. It may or may not. Often it splits fairly quickly.

Gets better. The original stators had a molded plastic wire jacket that was round & smooth. Now the stator makers are using a normal wire sleeve that is way too big for the wires, so it folds & wrinkles at both the inner boot & outer boot.

Dealing with that as we speak... I used tiny zip tie on inner boot above chain. I use Suzuki Bond silicon sealant on the outer boot, both in the wire sleeve & the OD of boot. All surfaces must be perfectly clean & bone dry. Smear on sealant. I used enough to fill wrinkles in wire jacket, & thin smear on OD. Then push boot in so it forces some silicon in along the wire to a degree. Quickly wipe squish out well. Even dampen small cloth with parts wash/carb cleaner lightly wipe any excess off. Let cure 24 hrs. This has worked very well for me.

The stator I took of was Wassell 2 wire. It leaked around wrinkles in wire. I installed Sparx 2 wire stator. Same sleeving & wrinkles. I'm still working on bike. Will road test in a week or two.
Don

 

[DrPat]

Hi Don, thanks heaps for this, I thought someone like you or Rambo or Peg might have some little wrinkles on the matter!! I really don't want to have the bloody thing off again, and that pernicious leak really shits me for some reason! The cleaning of surfaces is as you say, paramount (we get isopropyl alcohol here for that), and I'll go for the zip tie idea too, hadn't thought of that, thanks!
2 wire stator must be easier, yes - mine seems to have that, and I've already fitted the 2-wire podtronics box, so no point trying to update that, just re-opens another can of worms...

You probably know of the trick with snipping a notch out of the casing gasket to accommodate the wire where it passes through? I think sometimes the full gasket will bear on the wire and make room for seepage, worth doing anyway...

What a bloody palaver for such a basic thing!! Thanks very much again!!

cheers Pat

 

[Rancidpegwoman]

Hi Pat,
I have a couple of things on this that I do, unfortunately they require removal of the primary cover.

1) Remove the metal guide sleeve that keeps the wire off of the primary chain seal the threads (ptfe tape, locktite, yamabond or fibre washer) and refit. I don’t worry which method as long as the threads are sealed.

2) Fit the boot a long way down the wire then thread the wire through the sleeve, you have to get the bullet connectors through one at a time, this is an awkward procedure. Set the wire in position so that it is held away from the primary chain and sharpie mark where it enters the metal guide sleeve, pull the wire back an inch. Now wrap the wire in ptfe tape 1/4" down from your mark. Keep wrapping until you form a ptfe bulge on the wire, that is big enough that needs to be forced into the metal sleeve but not so tight that you damage the wire getting it in. If it is too loose add a few turns of ptfe tape, if it is too tight remove a few turns. You are aiming to achieve a fit where the ptfe tape is compressed hard around the wire, but can still be removed if required. With a combination of pulling the wire and pressing the ptfe bulge with a blunt rod (think: teaspoon handle or similar) force the wire+ptfe bulge into the guide sleeve until your previous sharpie mark lines up. Work the sealing boot up the wire and push over the end of the sleeve, fit the plastic locking clamp on the other side of the case.


Regards
Peg.

 

[rambo]

I use 300c Heatmate black silicone used for sealing boilers or making gaskets. Available in builders merchants. the same silicone i use for cylinder head exhaust sealing. Very large tube to fit in a caulking gun and about £6 here.

 

[TR7RVMan]

Hi Peg, Very clever idea with the Teflon tape! I’ll try that next time.
Don

 

[speedrattle]

i just change my oil all the time so its clean. then even though it still leaks, you can't see it as easily.

 

[Freakmaster]

The original stators had a molded plastic wire jacket that was round & smooth. Now the stator makers are using a normal wire sleeve that is way too big for the wires, so it folds & wrinkles at both the inner boot & outer boot.

Got to agree, I've become a bit like a dog with replacement parts, 'that's just the way it is'. This insulation jacket they use also becomes brittle with the heat and doesn't last. A method I've used is to completely remove it, bar 1/2" at the coils. Slide a silicon tube, (Car Builder Solutions) Using clear silicon as a lube, as it's a bit tight, one cable at a time, down it's entire length. Seal both ends with silicon. You may need 5mm ID if it's a three wire. It's been on for a while with no sign of deterioration. Benefit is it also remains supple and you get a good tight fit on case.

 

[TR7RVMan]

Hi DrPat, What do you mean about cutting notch in gasket near wire?

The primary gaskets I get don't foul wire or steel tube.

The gaskets I get are actually 650 2 row chain gaskets. I have to trim them around back & the thin area at bottom so they don't rub chain or tensioner bottom. But top is ok. Correct 750 3 row gaskets are made, but costly.
Don

 

[StuartMac]

Hi,

original stators had a molded plastic wire jacket that was round & smooth. Now the stator makers are using a normal wire sleeve that is way too big for the wires, so it folds & wrinkles at both the inner boot & outer boot.

Now wrap the wire in ptfe tape 1/4" down from your mark. Keep wrapping until you form a ptfe bulge on the wire,

If the stator has a sleeve over the wires that slides, why not just slide or cut it off and replace it with heatshrink? If the shrunk heatshrink isn't a large enough OD to make good seal inside the existing seals, add more layers of heatshrink in way of the seals 'til they do make a good seal?

Hth.

Regards,

 

[DrPat]

Hi everyone, and thanks for all the excellent tthoughts on that accursed alternator wire seal - especially that tip from Peg - awesome procedure, I will try it for sure. HOWEVER, now I get the casing off to fit the new stator, I find to my aabsolute horror, this (see pics if they downloaded alright)!!!

Looks like the stator resin has at some stage since I fixed the clutch a year or so ago, disintegrated! Man, it is carnage in there. I only did 100 miles last March before the lack of charging stopped me, and I came home in a truck, Then over winter intermittently chased the rectifier problem and fitted the Podtronic box; finally got it going a week ago, but still not charging - and here, maybe (haha) is the problem. Holy crap!! Anyone seen anything like this before?

Ther was always a strange smell about the bike: I presume that was cooking stator resin...

****!! What possessed me to go back to Meriden after a pleasant 20 years at Hinckley....????

Pat

 

[TR7RVMan]

Hi Pat, I've heard of this before, but never seen it. Wow a lot of ground up parts.

Did motor sound odd or anything to give a clue of the damage? Does motor turn over now or is it locked by the broken parts?

That's too bad. Hope no damage to chain or sprockets.
Don

 

[StuartMac]

Hi Pat,

Looks like the stator resin has at some stage
disintegrated

Mmmm ... looks like a wee bit more than that ... educated guess says the rotor was the cause? Also rotor nut tab washer doesn't appear to have been bent against at least one of the nut flats?

What year is the bike? 2-wire stator wouldn't be original unless the bike's specifically a '78 T140E. Even then, ime you'd have been wiser to make the replacement (and previously the reg./rec.) 3-phase.

Risking telling you things you know already:-

. Before fitting new rotor and stator, yank the end of the crank around with some force, to check for any obvious play (knackered main bearing ).

. On the basis that any new rotor is Wassell, check:-

.. the rotor outer is absolutely concentric with its centre (Wassell can't always manage this ...);

.. the rotor is a sliding fit on the crank, not tight or loose ('original Lucas' managed .750"-.7505", Wassell can't always ... ).

. New rotor-stator clearance is between .008" and .012" all the way round, checked at least three times, moving the crank/rotor between each check.

. New rotor and stator, ime it can be difficult to get the rotor concentric within the stator, particularly as the OIF has the limitation of two stator mounting studs protruding through the primary cover ... 😖

.. The method I've used for years is to assemble the rotor inside the stator spaced apart by several shims cut from an ally drinks can (ally because it isn't magnetic and won't stick to the rotor, also I make the shims so they stick out well beyond the stator and rotor so, after assembly's complete, I can grab 'em with pliers to pull 'em out). Or apparently some plastic drinks bottles are the correct size a cut ring will fit between rotor and stator?

.. Once I have a complete assembly of rotor-'n'-stator, I slide it on to both crank and stator mounting studs, this shows if there's any misalignment that'll interfere with concentricity and correct clearance once the the shim/s is/are removed.

.. Stator mounting holes are intentionally a tight fit on the studs. Any difficulty fitting rotor-stator assembly, I prefer to move the stator studs - rather than enlarging any stator mounting holes - 'til the assembly slides on to both crank and studs; however, none of my Triumphs have two of the studs poking through the primary cover ...

.. Once the rotor-stator assembly slides on to both crank and stator mounting studs, when both components are secured, when the shim/s is/are pulled out, there should be the aforementioned clearance all the way 'round.

What possessed me to go back to Meriden after a pleasant 20 years at Hinckley....?

You missed having things to do when you couldn't ride and the sense of achievement when the bike finished a trip without a problem ...

Hth.

Regards.

 

[DrPat]

Hi Don, thanks mate...yeah I'm a bit gutted, never seen this before. The motor sounded fine actually, I guess it's mainly chewed up the resin and copper windings and all that, but the rotor has also disintegrated apart from the central sleeve of it that wraps round the shaft. A couple more pics for your amusement.

So...I have had absolutely zero luck with this accursed machine. May as well have scored an utter basket case and started from the beginning. Anyway, I'll get a rotor and woodruff key and tab washer to go with the nice new stator, and continue on I guess. Disintegrating alternators do smell interesting - sortof like home baking of some sort, and THAT is what I've been smelling every time I've started this thing...

cheers, and thanks for the wire sealing wisdom....

Pat

 

[DrPat]

Hi Stuart, our posts criss-crossed just then - thanks heaps for all that advice, I will take all those steps when I get a new rotor, that's extremely helpful. I knew clearance all round was essential, but that's good method!!! - cheers agin - Pat

 

[dr.blom]

I'm guessing you have really loud pipes or very good earplugs? That must have made at least a little noise? Lucky it didnt go kaboom any way!
Im not looking forward to replacing my 53 year old stator or sealing grommet, which are pretty much like new.. dont think these indian made "lucas" stators or papier maché-rubber grommets will last that long.

 

[StuartMac]

Hi Pat,

From what I know, that doesn't appear to have been an original rotor on either a '78 or '79-on T140E.

Older (pre-'71?) Lucas rotors, the magnets simply sat on the faces of that central hex., held in place by the material cast around them. The problem is when the cast material comes loose from the central hex.; then, when the engine is accelerated and decelerated, the loose magnets are pushed outwards by the hex. ... even with the max. twelve thou. clearance, not long before the rotor magnets start whacking the ends of the stator coil cores ...

Still, look on the bright side, the old rotor hex. is a useful tool for turning the crank during rebuilds?

Commiserations.

Hth.

Regards,

 

[rambo]

When my main bearing wore, the rotor just began touching the stator. i could hear it immediately. i was able to re-use rotor and stator. I would have thought all that metal clanging around would have made a lot of noise. Very lucky the crank end did not shear off. i notice a lot of these new stators fail in short order. I am still using the stator that was fitted when i bought the bike and keep some old spare ones just in case. I have had one rotor failure when it lost magnetism but never that sort of damage.

 

[DrPat]

Hi Rambo, good to hear from you; yeah, I calculate I might have done about 90 miles with a disintegrating alternator there, yet the motor starts beautifully, runs great, no grievous noises other than the usual, just this faint smell of baking (or something). Only sympton was that the thing was not charging (which led me up other rabbit holes).
Just washing the debris out now, I'm hoping that this was a closed system and no debris could really go anywhere else, except maybe into the airbox, and there was nothing untoward there when I replaced the rectifier etc with the Podtronics box.
Only thing is, now my confidence in the supposed rebuild the motor had before I bought it is a bit low, especially if, as Stuart suspects, that rotor was not correct for T140s. I had wondered why there was a single phase system, but I suppose a lot can happen to a machine in 41 years...

Feeling somewhat more sanguine this morning, rotors are easy to source here, what else could possibly go wrong...??? hahahahahaha
Thanks for the input and commiserations everyone, very much appreciated!!!!
Pat

 

[Rancidpegwoman]

Hi Pat,
It would be useful if you drew some arrows on your photos, so that I can find where the damage is! 😊

joking apart, that is a spectacular breakdown.
Hopefully the magnets will have captured most of the metal particles, and the resin will have crushed down.

The engine breathes into the primary via the the crankshaft main bearing, so it might be worthwhile visually checking the bearing for debris.
I think I would be inclined to remove the crankcase drain plug and check if that is still clean.
I would definitely change the engine oil.
regards
Peg