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Discussion Starter · #81 ·
Oil Drill Way Questions: My 1969 T120R engine had a Routt 750 kit with no oil way in the Cylinder, and my right (timing) side case has a plug in the oil drill way. So it last ran with tappets without the holes for oil passage. The new 750 Cylinder I purchased has the oil drill way. Since I am going to have to replace my old tappets (pitting and scoring) I am going to get the exhaust tappets with the oil hole. My question is about removing/drilling out the plug of the oil way on my timing side case. So, do I drill this out with an appropriate diameter drill bit? Also, how far do I need to drill the hole? Perhaps this will become apparent while drilling?If any of you have done this before I’d appreciate your comments on how to proceed. Once it is drilled, do I then need to install a hollow dowel? Thanks for your comments!

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Hi,
you familiar with
Motalia
seems they have a searchable way to find Triumph fasteners by part number.
I know of them but never used them.

Ime, there are several pitfalls in just relying on what's on the bike or on a supplier that relies on Triumph fastener data:-

. Data has misprints - I'm still finding 'em more than forty years after I first replaced a fastener with stainless. :( E.g. I found only recently the '68/'69 fork drain screw listing in the StainlessBits spreadsheet is wrong - in reality, it's 2BA; in StainlessBits, one alternative is 5/16"-26, :eek: the other is 10-24 (the latter is a common mistake in the StainlessBits spreadsheet and, 'til they're all found and Greg can correct them, they're in the database too. :( If you buy from a British supplier, cock-ups'll be both time-consuming and expensive whether you return incorrect parts for replacement, or suck up the costs of keeping 'em and ordering correct. :(

. Even if the data is correct, ime, parts over half-a-century old, particularly 'blind' holes (e.g. cover screws into crankcase) you'll find a mixture of old gasket goo and bits of swarf packed into the ends. As a matter of course, I clean all threads with the connect tap or die; blind holes tap with grease in the flutes - the gasket goo and swarf comes out stuck to the grease. (y)

. Blind hole cleaned, you'll often find it isn't threaded to the bottom. Assuming you're using HSS taps, especially into ally, you can use the same tap-with-grease in the flutes to extend the thread to the bottom of the blind hole.

. Then you can find the next-longer fastener will fit. (y)

Hth.

Regards,
 

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Discussion Starter · #86 ·
I finally got some time to install my cam bushings. The cases were very clean. I put the bushings in the freezer for a couple of hours and then installed them with the driver tool sold by Lowbrow customs. Then used the reaming tool for the bushings with the cases bolted together. I fitted the cams and put the cases together and it seems that they are a good fit. Now on to replacing some bearings.

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Discussion Starter · #87 ·
I’m getting ready to reassemble my clutch shock absorber unit with new rubber bits. I’ve also got new screws since the old ones were messed up a bit. I’d appreciate any comments on how to get this together as I’ve read getting the new rubber bits in can be a challenge. Also - what it the recommendation for loctite? I’m assuming a bit of red loctite? Thanks for any advice!
 

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Probably best on the bike, doesn't have to be fully assembled, but you need the hub & centre on the mainshaft, then use your clutch locking tool (the kind with the arm) to turn the outer bit so you can shove the rubbers in place.
 

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Discussion Starter · #89 ·
Probably best on the bike, doesn't have to be fully assembled, but you need the hub & centre on the mainshaft, then use your clutch locking tool (the kind with the arm) to turn the outer bit so you can shove the rubbers in place.
Thanks for this. Do you use loctite for the screws when assembling? I’m hearing different opinions on this?
 

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Discussion Starter · #91 ·
I’ve been waiting on some new cams and tappets so went to work on the frame, completely disassembling it. I took the forks apart tonight and would appreciate any comments. I am pretty sure these are forks from a 1969 Bonneville. The insides were a mess, lots of corrosion, so I’ll be needing to get a number of parts. These measure 6 3/4 inches stanchion to stanchion. On the right side stanchion there are a couple of pits about mid-way so I’m wondering if this is a problem to rebuild? On the left stanchion there are a couple of pits also, however they are very low on the stanchion. Thanks for any comments.

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Hi,
forks
measure 6 3/4 inches stanchion to stanchion
from a 1969 Bonneville
The 6-3/4" is anything '69-on with a drum brake.

The back edges of the bottom yoke show the original bike had a small tank - as well as a Bonnie, could be TR6C, T100R or T100C. As cast, the yoke had a triangle of steel on each back edge; yokes for larger-tank bikes like e.g. TR6R or triples kept the triangles, to restrict the fork lock so the stanchions or top yoke didn't hit the tank on full lock; yokes for smaller-tank bikes had the triangles ground off during machining after casting.

'69 sliders originally had a 2BA hex. bolt (setscrew) for the drain plug, '70-on had a cheesehead Pozidrive screw, but also 2BA. Be aware '68 brake-side slider will fit, also originally had a 2BA hex. setscrew for the drain plug but, because pre-'69 legs were only 6-1/2" apart, the brake anchor is narrower than '69-on and, if fitted to 6-3/4" forks, won't engage fully the brake plate anchor slot. (n)

Afaik, Triumph didn't first fit hard-chromed stanchions 'til '70.

View attachment 774278
right side stanchion there are a couple of pits about mid-way so I’m wondering if this is a problem to rebuild?
Mmmm ... the vertical lines show it's where the seal has moved up-and-down over the slider when the area's been covered in dirt and/or rust? (n)

How bad are the scratches? If you can feel 'em with a fingernail, the stanchion wants replacing or rechroming.

Otoh, if the "scratches" only show up more in a photo. because of the flash, while Paul is correct about the pits being "critical" (fork oil will collect in the pits when the seal's above them then leak out when the seal's below 'em :(); if they're the only pits, before replacing the stanchion, you might want to try something from my misspent youth - degrease the pits thoroughly, mix up a small amount of 2-part epoxy, smear it into the pits with a finger, let it dry hard, sand off the excess over the surrounding chrome, assemble the leg parts, fill with oil and see if it still leaks ... In GB, leaking fork seal is a fail in the annual safety inspection; new stanchions were expensive luxuries to impoverished youths with social lives to maintain ...

When considering stanchion reuse or replacement, bear in mind all stanchions bend just under the bottom yoke, even if the bike hasn't been involved in a crash. So, ideally, you'd straighten any stanchion before you reused it; if you didn't straighten both stanchions before reuse, you'd ensure both remained exactly parallel throughout their length when refitted; you wouldn't mix one unstraightened used stanchion with a new one.

Hth.

Regards,
 

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Discussion Starter · #95 ·
Hi,

The 6-3/4" is anything '69-on with a drum brake.

The back edges of the bottom yoke show the original bike had a small tank - as well as a Bonnie, could be TR6C, T100R or T100C. As cast, the yoke had a triangle of steel on each back edge; yokes for larger-tank bikes like e.g. TR6R or triples kept the triangles, to restrict the fork lock so the stanchions or top yoke didn't hit the tank on full lock; yokes for smaller-tank bikes had the triangles ground off during machining after casting.

'69 sliders originally had a 2BA hex. bolt (setscrew) for the drain plug, '70-on had a cheesehead Pozidrive screw, but also 2BA. Be aware '68 brake-side slider will fit, also originally had a 2BA hex. setscrew for the drain plug but, because pre-'69 legs were only 6-1/2" apart, the brake anchor is narrower than '69-on and, if fitted to 6-3/4" forks, won't engage fully the brake plate anchor slot. (n)

Afaik, Triumph didn't first fit hard-chromed stanchions 'til '70.


Mmmm ... the vertical lines show it's where the seal has moved up-and-down over the slider when the area's been covered in dirt and/or rust? (n)

How bad are the scratches? If you can feel 'em with a fingernail, the stanchion wants replacing or rechroming.

Otoh, if the "scratches" only show up more in a photo. because of the flash, while Paul is correct about the pits being "critical" (fork oil will collect in the pits when the seal's above them then leak out when the seal's below 'em :(); if they're the only pits, before replacing the stanchion, you might want to try something from my misspent youth - degrease the pits thoroughly, mix up a small amount of 2-part epoxy, smear it into the pits with a finger, let it dry hard, sand off the excess over the surrounding chrome, assemble the leg parts, fill with oil and see if it still leaks ... In GB, leaking fork seal is a fail in the annual safety inspection; new stanchions were expensive luxuries to impoverished youths with social lives to maintain ...

When considering stanchion reuse or replacement, bear in mind all stanchions bend just under the bottom yoke, even if the bike hasn't been involved in a crash. So, ideally, you'd straighten any stanchion before you reused it; if you didn't straighten both stanchions before reuse, you'd ensure both remained exactly parallel throughout their length when refitted; you wouldn't mix one unstraightened used stanchion with a new one.

Hth.

Regards,
StuartMac I appreciate the history of my fork parts. It seems this bike has a lot of disparate parts and most of the fasteners are pretty banged up too. I can feel the scratches with my fingernails, so looks like I will need to replace most everything on the forks except the yokes, sliders and steering damper. I'm pretty sure this bike was sitting still for years with water in the forks where these pits appear. The good news is when I'm done I suppose I'll know how it all works.
 

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Discussion Starter · #96 ·
I’m working to get the frame parts ready for painting or powder coating. I see that on the main frame the main tube ends with an open hole. Is this suppose to have some sort of cap on it? I have not seen anything in the parts books but it seems like it would be a good idea.


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Hi,
will need to replace most everything on the forks except the yokes, sliders and steering damper.
Mmmm ... :(

Couple of things to watch with new stanchions:-

. Make sure what you get are the correct diameter, as in the workshop manual - oversize will be difficult to fit in either yoke, undersize will be difficult to clamp particularly the bottom yoke. :(

. Ask the seller to verify the threads. At some point, Triumph swapped from 26 tpi Cycle to 28 tpi Unified; in the past, buyers have found the 28 tpi thread used on earlier stanchions; not a biggie in itself because the late conical "Top cap nut" can be used, just a pain if you have to delay assembly when, if known before dispatch, new corresponding Top cap nuts could've been ordered with the new stanchions.

Btw, something I forgot in my previous post - pre-'70 sliders have 5/16"-26 (Cycle) threads and used bolts to clamp the wheel spindle, '70-on have 5/16"-24 (UNF) threads and used studs and nuts.

Hth.

Regards,
 

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Discussion Starter · #98 ·
Hi,

Mmmm ... :(

Couple of things to watch with new stanchions:-

. Make sure what you get are the correct diameter, as in the workshop manual - oversize will be difficult to fit in either yoke, undersize will be difficult to clamp particularly the bottom yoke. :(

. Ask the seller to verify the threads. At some point, Triumph swapped from 26 tpi Cycle to 28 tpi Unified; in the past, buyers have found the 28 tpi thread used on earlier stanchions; not a biggie in itself because the late conical "Top cap nut" can be used, just a pain if you have to delay assembly when, if known before dispatch, new corresponding Top cap nuts could've been ordered with the new stanchions.

Btw, something I forgot in my previous post - pre-'70 sliders have 5/16"-26 (Cycle) threads and used bolts to clamp the wheel spindle, '70-on have 5/16"-24 (UNF) threads and used studs and nuts.

Hth.

Regards,
I would not have thought of the over/undersize issue on stanchions so I will observe your comments when ordering, as well as regarding the top cap nut. My sliders do have bolts to clamp the wheel spindle. I was going to need the top cap nut anyway as mine are rusted through the chrome. Thanks and Cheers.
 

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Discussion Starter · #99 ·
Rocker arm question. See the photo of one of my rocker arms. The face of the tappet adjuster is banged up so I am intending to replace these. I purchased some adjusters with the mushroom type head. Also see the ball end, mine have the hole in the end. I have been reading about changes made to the rocker arm and the difference between the ball with the oil hole and the ball end without. Is the ball end something I should replace also? If so, since this is a pin I’d appreciate advice on how to the the repair. Thank you.

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Hi,
Rocker arm question.
ball end, mine have the hole in the end. I have been reading about changes made to the rocker arm and the difference between the ball with the oil hole and the ball end without. Is the ball end something I should replace also?
Not necessarily? The change was advised by Umberslade Hall mainly because the 'no-hole' rocker was cheaper to make, but is also slightly stronger. Assuming you don't expect to thrash the 'nads off your rebuilt engine at every opportunity, the rockers in your photo. should be fine?

Changing to 'no-hole' rockers is something of a can of worms:-

. the rockers-'n'-washers assembly diagram in the 650 workshop manual becomes wrong, you have to use the one in the triples manuals;

. if you reuse the existing rocker shafts, they need an oil transfer groove or scroll machining along them;

. the lateral position of a shaft within the box and rockers could be a problem when the domed nuts are tightened.

The face of the tappet adjuster is banged up so I am intending to replace these. I purchased some adjusters with the mushroom type head.
Mmmm ... there's better design, if they're available to fit:-

. In theory, the mushroom head allows for the rocker-arm moving in an arc while the valve stem moves in a straight line. Snag with the mushroom-head is it's still point contact on the end of the valve stem; if the adjuster has to slide across the valve stem during actuation, that force is concentrated in one small area in both adjuster and valve stem tip.

. @DMadigan Dave developed an adjuster nicknamed "elephant's foot" for the triples from those used by Porsche and by Mercedes-Benz on the 190 engine. Each adjuster is in two parts, threaded part in the rocker, circular part covering the entire valve stem top, joint between the two takes care of the difference between rocker arc and valve straight movements. The advantage is, if the rocker arc imparts any sideways force, it's spread over the whole adjuster 'foot' and valve stem tip with the chance an oil film can survive between.

Dave makes his for the triples so they can have a 5/16"-24 thread to match triple rockers - Porsche and MB adjusters are M8 Fine thread, close but no cigar and, rockers being hardened, rethreading triples' rockers for metric adjusters needed two or three taps. :(

What I don't know is if Dave makes his adjusters to suit the 5/16"-26 thread on pre-'73 twin rockers. However, now I've name-checked him, the Forum software will show him a link next time he checks in.

Or, if you must change the rockers, I don't know whether 750 rockers - with 5/16"-24 adjuster thread - would fit?

Or use the mushroom-head adjusters you've bought, with valve stems shortened for lash caps? Any later wear, the whole valve doesn't have to be changed, only adjuster and/or lash cap. (y)

Hth.

Regards,
 
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