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Discussion Starter · #1 · (Edited)
Triumph Crank/bottom end rebuild pics..tons of pics..dialup dont bother.

disclaimer: I have NO CLUE what the hell im doing. please don't take this as bible, or any sort of helpfull tech post.

ALSO. to anyone who DOES know wtf they are doing, please please PLEASE feel free to tell me where im screwing up or if im overlooking something.

backstory: So I tore down my motor, used all the correct pullers, etc. (thanks to Tony!) and i wouldnt recommend trying to do it without them. I busted the clutch center trying to use a gear pulller on the clutch center, that sucked. my fault.

I'm following a combination of the haynes manual, as well as another manual i have.

So since im super anal retentive, and poor. i have to clean everything so i can eat off it, and since i dont have a media blaster or even a parts washer, i resort to buckets, bowls, mineral spirits, soapy water, etc. etc.




all clean




I inspected the journals and there is no scoring or anything (note: in the pictures, they look dull as they just came out of the soapy water, and i didnt polish them yet)
 

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Discussion Starter · #3 ·
BTW - the sludge trap was pretty dirty...not clogged, but enough to justify me tearing up the bottom end.

i dont have pics of that but i followed a post on here on the proper removal.

so....from the specs it doesnt look like im going to need a regrind (i think...you guys let me know if im an idiot) which is pretty good.



so i looked at the bearings, and it seems 1 side was scored pretty bad. not sure why as the crank is perfect. anyone explain?
 

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Discussion Starter · #5 · (Edited)
then i moved to the cases....I heated the cases up to drop the main bearing out....bearing seems fine to me...no play, spins free....another one of those "should I replace it anyways" question....although this one is a little more expensive.


so i spent a good portion cleaning the timing side case.....it had some spray paint on it, etc.

first i scrubbed it with mineral spirits and a toothbrush, then i put some naval jelly on there and rinsed in a bucket of hot soapy water, then had to use some stripper (then again in HOT soapy water to soak for a little) to get the liquid gasket and the rest of the paint off, seemed to work well and clean up well.




 

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Discussion Starter · #7 ·
miced the cam bushings they came in on spec. i was worried about these as the cams seem to have a tad bit of play in there, is this normal? not much, just a tad.


idler gear bushing came in on spec



Tomorrow ill work on the other case alhtough i did make sure the cam bushings were in spec. I also cleaned up the cams, ill take pictures tomorrow but they look good.

So.. it looks like im going to have to order:
sludge trap, plug
rod bearings standard size
pistons, i have a question here...i have a set of jugs they are .060 over they could be runnable as is, but im not comfortable with .60 over...can i get them bored and sleeved, (well i know i can) and when i do should i get them rebored to standard bore? or say 20 or 30 over???

after than ill send it out to get balanced. (unless anyone has any ways to do it in house)

then the bottom end will be done. (although befor ei put it together im goin gto take a look at the needle bearing tin the gearbox, and check those bearings out.

well that was a looong post sorry to bore you guys but it helps me to see if i forgot anything and i hope if im doing something wrong, or my specs are wrong that someone points it out as this is the first time i have touched a motor.
 

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so i looked at the bearings, and it seems 1 side was scored pretty bad. not sure why as the crank is perfect. anyone explain? - my understanding is one side gets less pressure, moreso on the 3-peice crank i have w/ the big void in the middle. im also reusing my main bearings, there as tight as new.
 

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zgears said:
so i looked at the bearings, and it seems 1 side was scored pretty bad. not sure why as the crank is perfect. anyone explain? - my understanding is one side gets less pressure, moreso on the 3-peice crank i have w/ the big void in the middle. im also reusing my main bearings, there as tight as new.
..

anything in a unit crank questionable area, I would start at when/if on the sludge trap, as it will restrict/stop one side first ..

Rob, you're doing this so open, pic-by-pic, search or e him for his build pic series - Jason McElroy .. has posted precision work step-by-step in immaculate conditions, of several motor builds, on several boards,

am Sure he has them hosted & available, and he does hang here .. try a pm ..

Doug ..

..

Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
 

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..

just read back your first ..

"I'm following a combination of the haynes manual, as well as another manual i have. "

Dave Steube - Classicbike here, or [email protected]com , has the original Tri-Cor manual the factory used to train their mechanics, and dealers' .. on unit rebuild; .. has on pdf or maybe disc ..

see about getting that one to study, especially while you have it apart ..

Knowlege is Power ..

most especially before your other power just Busts Hell out of things ..

..

Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
 

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yer kids will be pissed when their Holloween candy tastes like parts cleaner


be very careful when using Vernier calipers to mic stuff....the reading you are getting on the calipers is only as good as how far those tips will reach.....and when I was machining for a living,I could get as much as .003 to .005 discrepancy in readings over using outside or inside mics rather than Vernier style calipers....which could mean the difference between in spec or out of spec.......use outside mics on the crank journals and preferably ones with blade-style tips.....reason being is that there could be more or less wear on certain regions of the journal itself......as for checking cylinder bore, the best tool to use being inside dial bore mics......that way you can see if the cylinders have any taper or eggshape when checking them.........I try and use plug guages on the bronze bushings......bushings are typically a LITTLE sloppier in fit than other types of bushings/bearings........the most important part is to check the bushings for scoring and to see if the oil pilot holes in the bush line up correctly with the corresponding oil journal hole in the peice it fits in........CAM BUSHINGS being the example..........mine had miced out fine but had deep scorews in them the exact shape of a flathead screwdriver (hmmm...wonder how it got that way?)........so I jerked `em out and replaced them

tech tip: If you find you need to replace the cam bushings,and you can`t figure out how to get the ones out of the left-side case half,I did this with great success..........I dropped a penny into the bottom of the cam bush hole and then inserted a 5/8 18 (unsure of actual thread pitch size but am sure it was 5/8 OD) tap into the cam bush.......screw in the tap and when it bottoms out on the penny,it will pull out the bush easily as you continue to turn the tap....the penny was to keep the tap from eating into the case half and boogering up that oil passageway


good luck and nice work so far
 

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Nice photos. For a 1st rebuild, it sounds like you have a good understanding of what to inspect.

I'm always a pessimist. If it were my rebuild, I wouldn't hesistate to replace the main bearings, unless you know some previous history or the accurate mileage. These bearings are not very expensive. If they are original, they are over 30 years old.

How many pock marks were on the sludge trap plug? This gives a clue to how many times the bike has been apart. The cam bushings will do high mileage, so they rarely need replacing. If the wrist pins are a good fit in the small end, you will be ok there too.

If the bore is in good shape, don't be afraid to run at +.060. Pistons are available in this size. You could get many miles/years before you have to resleeve. If you choose to resleeve the cylinder, might as well go back to standard bore.

Looks like you're off to a good start. I took apart a nasty '71 T-120 a couple of weeks ago, and it is the most hammered, abused, and worn out engine I have seen in quite awhile. Everything in the primary is junk, the cams are shot, the crank needs a regrind, and the top end is toast. This shit can get expensive in short order!
 

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You probably know this already, but use an allen plug for the sludge trap, it'll make future rebuilders happy, especially if it's you.

I have that same ghetto caliper from harbor freight, by the way.
 

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fuck yeah caffeine way to dive right in!!!

you have successfully motivated me to take something apart today
 

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Discussion Starter · #17 ·
Dragon said:
..
just read back your first ..

"I'm following a combination of the haynes manual, as well as another manual i have. "

Dave Steube - Classicbike here, or [email protected] , has the original Tri-Cor manual the factory used to train their mechanics, and dealers' .. on unit rebuild; .. has on pdf or maybe disc ..

see about getting that one to study, especially while you have it apart ..

Knowlege is Power ..

most especially before your other power just Busts Hell out of things ..

..
thats the other one im using. why do your posts always look big and funny?
 

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Rob your way ahead of me now.. I havn't even split my cases yet! LOL

I'm glad your posting this though, i'm sure it'll help me along with mine once i do get rolling on it..

Thanks for the post, and thanks to those who responded..
You can never learn enough, and reading from those who have done it is sure helps..
 
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