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Discussion Starter #1
I was removing the primary case on my '70 T100c. Never had it off before and someone, somehow used some gasket sealer that glued the cover on TIGHT!. And I mean TIGHT.
Does anyone have any idea on how I can remove it.
Thank you,
Steve
 

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Try heating the joint to soften whatever’s gluing it and gentle application of a rubber mallet around the joint. There are no dowels locating the cover so you should be able to move it up or down a tiny amount but enough to break the joint. Have you removed the primary chain adjuster sleeve nut? On the 500’s this is housed in the primary cover rather than the crankcase as on the 650’s. This wouldn’t necessarily prevent you breaking the joint but it would make life difficult removing the cover later.
 

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Discussion Starter #3
Try heating the joint to soften whatever’s gluing it and gentle application of a rubber mallet around the joint. There are no dowels locating the cover so you should be able to move it up or down a tiny amount but enough to break the joint. Have you removed the primary chain adjuster sleeve nut? On the 500’s this is housed in the primary cover rather than the crankcase as on the 650’s. This wouldn’t necessarily prevent you breaking the joint but it would make life difficult removing the cover later.
Thank you
I'll try heating the cover joint this afternoon. I have a Mikita heat gun that should work
I have removed the adjuster nut. Is necessary to remove the adjuster screw also?
Thank you
Steve
 

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Just in case Rusty doesn't see this shortly (he and I have the exact same T100Rs), by the adjuster nut I assume you mean the blanking plug? If you've taken that off there should be a few drips of oil coming out of that now - it takes overnight to drain the primary (assuming there's oil in it!). I'd take the adjuster screw out now (actually a cylindrical nut with a slot in the outer end, that screws up along the adjuster rod and compresses the tensioner blade into an arc that then tensions the primary chain.

That nut (aka screw) can be tricky to undo as there's not much room for a screwdriver in the hole; there's actually a tool for this but the right screwdriver will do. The nut will then come all the way out and give you a bit more freedom to wiggle the primary cover free. The cylindrical adjuster nut is a good fit in the primary cover hole and that will hold the primary cover in place.

You'll need a bit of patience as the nut is quite a long way up inside the hole, and is maybe 30mm long, so unscrewing it can take a while.

Rusty will no doubt be along shortly! But the above is how I'd do it.
 

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I have removed the adjuster nut. Is necessary to remove the adjuster screw also?
I think we may be talking at crossed purposes. Apologies if you know all of this, I found it quite tricky getting the cover off for the first time but a lot easier once I could see how it all went together. Using this parts book page 34;

http://classicbike.biz/Triumph/Parts/1970s/71PartsManualTriumph500s.pdf

Remove item 33 and drain the oil it’ll take a while because inside there you’ll find item 32 which is the primary drive chain adjuster sleeve nut. This needs to be removed before you can take off the primary cover, you can get away with a screwdriver which fits in the hole but it’s a lot easier with the proper tool;

Triumph Primary Chain Adjuster Tool (1) - 61-7012 - T90 / T100 / T120 / T140

Keep going and eventually the adjuster sleeve nut will come out. Once you’ve then broken the gasket joint the cover will come off but don’t just pull it towards you. The threaded rod to which the adjuster sleeve nut was attached (item 10) will still be in the primary cover hole so wriggle the cover backwards until it’s free.
 

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Hi Steve,
Once the bolts and the tensioner is removed.
In the middle of the cover is the blanking plug that covers the clutch pushrod adjuster. If you remove this plug you will find it is hollow to allow the clutch pushrod to move. Find some coins that just fit inside the hollow. Bind them together with tape and push them in the hollow part until the space is filled. Refit the plug. The plug must screw all of the way in on full threads, if it does not screw fully in, remove one of the coins and try again. Not using all of the thread risks stripping them, so be careful.
Now apply some pressure to the clutch lever, the clutch pushrod will press against the coins and tension the case seal.
You are not looking to break the seal with just this pressure, you just need to apply a little pressure in the right direction to assist breaking the seal. Now strike sharply around the edge of the cover with a rubber mallet, the shock and tension combined should easily break the seal.

I have taken to placing sealant on one side of the gasket and grease on the other. So that in an roadside emergency the cover can be removed easily due to the grease, but the gasket stays in place undamaged due to the sealant.

good luck
Regards Peg.
 

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Hi Steve,
Once the bolts and the tensioner is removed.
In the middle of the cover is the blanking plug that covers the clutch pushrod adjuster. If you remove this plug you will find it is hollow to allow the clutch pushrod to move. Find some coins that just fit inside the hollow. Bind them together with tape and push them in the hollow part until the space is filled. Refit the plug. The plug must screw all of the way in on full threads, if it does not screw fully in, remove one of the coins and try again. Not using all of the thread risks stripping them, so be careful.
Now apply some pressure to the clutch lever, the clutch pushrod will press against the coins and tension the case seal.
You are not looking to break the seal with just this pressure, you just need to apply a little pressure in the right direction to assist breaking the seal. Now strike sharply around the edge of the cover with a rubber mallet, the shock and tension combined should easily break the seal.

I have taken to placing sealant on one side of the gasket and grease on the other. So that in an roadside emergency the cover can be removed easily due to the grease, but the gasket stays in place undamaged due to the sealant.

good luck
Regards Peg.
That coin trick is a clever idea - must remember that.

I also 'glue' a gasket to one face of the joint - I use WellSeal so the gasket stays in place, and then grease on the gasket face so it swells a bit and seals well.
 

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Discussion Starter #8
That coin trick is a clever idea - must remember that.

I also 'glue' a gasket to one face of the joint - I use WellSeal so the gasket stays in place, and then grease on the gasket face so it swells a bit and seals well.
Thank you all for the suggestions.

Heat gunned the cover seam for about 10 minutes and popped it off!

The gasket was glued to the cover and a lot of it was smeared on the engine casting. I could not screw the chain adjusting screw all the way out, but the cover giggled off anyway.

The reason I pulled the cover in the first place was because with the clutch lever pulled in it was difficult for the clutch to release all the way. Adjusting it at the lever did not help.

I noticed the clutch cover is very slightly canted. Can you tell me the best way to remedy this?

Thanx in advance.
Steve
P.S, Also, I read somewhere that the "70 T100C has three small holes to let oil in and also drain from the crankcase to permit the primary case to be lubed. If this is true, can you tell me where they are located?
 

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You can see one of them just below the stator stud on the right, the other two are obscured by the stud but they are there. This was introduced for the 1970 model year and you should also see a large bore breather pipe venting the primary drive case. Above the clutch in the picture.
721084
 

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Discussion Starter #11
You can see one of them just below the stator stud on the right, the other two are obscured by the stud but they are there. This was introduced for the 1970 model year and you should also see a large bore breather pipe venting the primary drive case. Above the clutch in the picture.
View attachment 721084
Thanks for the pic. They sure are tiny! Easy to miss. And they seemed clogged.
Also my clutch cable snapped so resume clutch adjustments when it arrives.
THANK you all again for the help.
Steve
 

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Hi Steve,

read somewhere that the "70 T100C has three small holes to let oil in and also drain from the crankcase to permit the primary case to be lubed.
To be clear:-

. The holes are only a drain from the primary chaincase into the crankcase. As the pistons rise and fall, the crankcase volume changes; when the pistons are falling, the air is pushed out of the crankcase into the primary through the drive-side main bearing and contains droplets of oil; these droplets are expected to condense in the primary chaincase before the air passes out into the large diameter plastic tube. The drain holes between primary and crankcase are to prevent the primary oil level rising more than just enough to lube the primary chain on the bottom of its run.

. While it's possible to allow just condensing oil droplets from the crankcase to fill the bottom of the chaincase after a service or primary reassembly, it isn't advisable; it's wiser to add the recommended quantity of engine oil to the primary.

gasket was glued to the cover and a lot of it was smeared on the engine casting.
Fwiw, I soften stuck gaskets with wood furniture paint stripper - it's relatively weak so it won't damage the metal gasket mating surface, nor will you damage the mating surface trying to remove stuck gasket. The paint stripper I use is a gel, so it can be painted on with an old paintbrush but it'll stick to the surface at any angle, it's water-soluble so wipes or washes off.

reason I pulled the cover in the first place was because with the clutch lever pulled in it was difficult for the clutch to release all the way.
Had you posted this before removing the primary cover, I would've advised first trying clutch/lever movement with just the clutch adjuster plug removed.

The C-range (unit 500 and 350 twins) primary covers are a vexed saga ...? To my certain knowledge, Meriden deepened it/them at least four times, sometimes with other changes (e.g. the separate cover over the alternator rotor) but also sometimes quietly, without even changing the part number (e.g. my '69 T100 has a '73-on cover, you wouldn't know the differences unless you had 'em side-by-side).

The other problem is many spares 'dealers' don't know the original E8782 (70-8782) clutch adjuster plug seal was a fibre washer, not an O-ring - Meriden changed the part during '69 without changing the part number. Then said 'dealers' supply a cheap thin generic O-ring just of about the right diameter, not a thick O-ring like Meriden originals ... :mad:

Any of the above can cause the plug to be too close to the primary adjuster screw, which clouts the plug's slot when you pull the handlebar lever, restricting the clutch movement. :(

could not screw the chain adjusting screw all the way out,
Probably because it had unscrewed from the chain adjuster rod anyway; the screw is quite a tight fit in its hole in the primary case.

Btw, when reassembling:-

. Stick the primary gasket to the crankcase side of the primary first. Fwiw, I've always used grease on both sides of the gasket, so next removal it simply peels off both cover and crankcase. (y)

. Fit the chain adjuster screw on the rod and screw it up to the chain adjuster (no tension on the adjuster) before attempting to refit the primary outer cover. If you don't, you'll never get the adjuster screw on the rod and you'll have to remove the primary cover again. Amhikt! ?

. When refitting the cover:-

.. hold it with the top edge some distance from the crankcase; you'll need to do this to slide the chain adjuster screw into the hole while the cover passes over the alternator and clutch;

.. as you slide the cover into position, pull it away from the crankcase - the chain tensioner can take a little sideways pull - if you don't pull the chaincase away from the primary, you'll ruckle up the gasket and it'll leak when you put oil in the chaincase. Amhikt! ?

.. For this reason, it's wise to have more than one new primary gasket on hand ... Amhikt ... :rolleyes:

noticed the clutch cover is very slightly canted. Can you tell me the best way to remedy this?
In what way is the cover "canted"? If it seals, I wouldn't try to "remedy" it; as above, they don't have a lot of spare metal on 'em and it's a lot harder and more expensive to add metal than to take it off.

Hth.

Regards,
 

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Discussion Starter #13
Hi Steve,


To be clear:-

. The holes are only a drain from the primary chaincase into the crankcase. As the pistons rise and fall, the crankcase volume changes; when the pistons are falling, the air is pushed out of the crankcase into the primary through the drive-side main bearing and contains droplets of oil; these droplets are expected to condense in the primary chaincase before the air passes out into the large diameter plastic tube. The drain holes between primary and crankcase are to prevent the primary oil level rising more than just enough to lube the primary chain on the bottom of its run.

. While it's possible to allow just condensing oil droplets from the crankcase to fill the bottom of the chaincase after a service or primary reassembly, it isn't advisable; it's wiser to add the recommended quantity of engine oil to the primary.


Fwiw, I soften stuck gaskets with wood furniture paint stripper - it's relatively weak so it won't damage the metal gasket mating surface, nor will you damage the mating surface trying to remove stuck gasket. The paint stripper I use is a gel, so it can be painted on with an old paintbrush but it'll stick to the surface at any angle, it's water-soluble so wipes or washes off.


Had you posted this before removing the primary cover, I would've advised first trying clutch/lever movement with just the clutch adjuster plug removed.

The C-range (unit 500 and 350 twins) primary covers are a vexed saga ...? To my certain knowledge, Meriden deepened it/them at least four times, sometimes with other changes (e.g. the separate cover over the alternator rotor) but also sometimes quietly, without even changing the part number (e.g. my '69 T100 has a '73-on cover, you wouldn't know the differences unless you had 'em side-by-side).

The other problem is many spares 'dealers' don't know the original E8782 (70-8782) clutch adjuster plug seal was a fibre washer, not an O-ring - Meriden changed the part during '69 without changing the part number. Then said 'dealers' supply a cheap thin generic O-ring just of about the right diameter, not a thick O-ring like Meriden originals ... :mad:

Any of the above can cause the plug to be too close to the primary adjuster screw, which clouts the plug's slot when you pull the handlebar lever, restricting the clutch movement. :(


Probably because it had unscrewed from the chain adjuster rod anyway; the screw is quite a tight fit in its hole in the primary case.

Btw, when reassembling:-

. Stick the primary gasket to the crankcase side of the primary first. Fwiw, I've always used grease on both sides of the gasket, so next removal it simply peels off both cover and crankcase. (y)

. Fit the chain adjuster screw on the rod and screw it up to the chain adjuster (no tension on the adjuster) before attempting to refit the primary outer cover. If you don't, you'll never get the adjuster screw on the rod and you'll have to remove the primary cover again. Amhikt! ?

. When refitting the cover:-

.. hold it with the top edge some distance from the crankcase; you'll need to do this to slide the chain adjuster screw into the hole while the cover passes over the alternator and clutch;

.. as you slide the cover into position, pull it away from the crankcase - the chain tensioner can take a little sideways pull - if you don't pull the chaincase away from the primary, you'll ruckle up the gasket and it'll leak when you put oil in the chaincase. Amhikt! ?

.. For this reason, it's wise to have more than one new primary gasket on hand ... Amhikt ... :rolleyes:


In what way is the cover "canted"? If it seals, I wouldn't try to "remedy" it; as above, they don't have a lot of spare metal on 'em and it's a lot harder and more expensive to add metal than to take it off.

Hth.

Regards,
As always, your post provided a wealth of information. Thank you.
I'm waiting for the new cable and a few other things to arrive.
I will observe your comments as I re-assemble the case and post the results or problems.
Steve
 
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