Triumph 750 engine tear down question. - Page 3

chaddhamilton · 05-18-2012, 11:53 AM

Quote:

Originally Posted by concours

That was run on Castrol 20-50 dino oil the whole way. It IS fitted with a Lockhart oil cooler. Did you notice the logo stamped on the crankshaft? That is a big reason why it lasted so long. That, and my buddy rides it gently, rather than a hammer.

Do you care to explain a little more about the crankshaft on that bike?

concours · 05-22-2012, 09:26 AM

Quote:

Originally Posted by chaddhamilton

Do you care to explain a little more about the crankshaft on that bike?

Precision balanced at Lindskog Balancing, back in 1980 http://lindskog.com/automotive-balancing.php

marksbonneville · 06-17-2012, 02:40 PM

Had a hell of a time diagnosing a bad fuse holder but once that was replaced she started right up and runs fantastic.

http://www.youtube.com/watch?v=Jo2q5...ature=youtu.be

bagpiper22 · 12-02-2012, 05:29 AM

Great thread. Thanks. I'm about to open the case on my 76 Bonnie, and I'm getting all the input I can before I do it. Primary drive and clutch is off, gearbox cover off, etc.

Quick question: there were differing opinions, but no clear answer: was there a case bolt behind the inner cover, or were you able to split the cases with transmission in place? Like you, I'm trying to get the crank out, while disturbing as little else as possible.

I'm also having a time with the pinion gear. I've read you can heat the case in an oven then remove the crank with pinion and main bearing in place. Is that what you did? I'll probably get the proper tool, but if there's something I can try in the meantime that won't hurt the engine, why not?

Lastly, I love the T140 pedestrian slicer license on the front fender in the video. Where did you get that?

Thanks again for the post, and everybody's replies.

Scott

concours · 12-02-2012, 06:10 AM

Quote:

Originally Posted by bagpiper22

Great thread. Thanks. I'm about to open the case on my 76 Bonnie, and I'm getting all the input I can before I do it. Primary drive and clutch is off, gearbox cover off, etc.

Quick question: there were differing opinions, but no clear answer: was there a case bolt behind the inner cover, or were you able to split the cases with transmission in place? Like you, I'm trying to get the crank out, while disturbing as little else as possible.

I'm also having a time with the pinion gear. I've read you can heat the case in an oven then remove the crank with pinion and main bearing in place. Is that what you did? I'll probably get the proper tool, but if there's something I can try in the meantime that won't hurt the engine, why not?

Lastly, I love the T140 pedestrian slicer license on the front fender in the video. Where did you get that?

Thanks again for the post, and everybody's replies.

Scott

Quite sure you'll need to remove the transmission. You DO have a workshop manual on hand, right? Be careful that you truly understand the timing gears alignment, marking. MANY eff ups over the years! It's more complex than it first appears!

marksbonneville · 12-02-2012, 06:40 AM

I did remove the transmission assembly but I could have removed the inner cover, removed the two bolts holding the case together and re installed the inner cover. Putting the transmission gears back was a challenge but in the end worked out ok. The other thing I learned was I did not need a crank pinion gear puller, I removed the crank and used a press, I spent a bundle on a pinion puller that did not do the job and was junk. A repair manual will be needed but you can find online copies. Hidden bolts???? hmm let me see how good my memory is.... lifter bolts inside the crank case, front stud used for the exhaust brackets, a screw is kind of hidden that hold the inner transmission cover......I may be missing something.
I picked up the pedestrian slicer back in '88, always gave her that special look.
After 25 years I sold the Triumph, tools, and manuals this last summer, great bike just was time to move on.

bagpiper22 · 12-02-2012, 06:45 AM

Yes...shop manual and exploded parts diagrams on hand. I'm not planning on removing the intake and exhaust timing gears. Just the center gear which slides right off. Everything else seems intact there. I'll be sure to line up the timing marks when I reassemble.

My goal is the sludge trap. This bike only has 7000 miles, but sat for 30 years, so whatever is in there is hard as a rock.

Once I get the engine back together, I can start in on the rest of the bike.

So if I have to remove the transmission outer cover, can I get to the case bolt without disturbing the transmission too much?

Thanks!

marksbonneville · 12-02-2012, 06:57 AM

Quote:

Originally Posted by bagpiper22

Yes...shop manual and exploded parts diagrams on hand. I'm not planning on removing the intake and exhaust timing gears. Just the center gear which sludes right off. Everything else seems intact there. I'll be sure to line up the timing marks when I reassemble.

My goal is the sludge trap. This bike only has 7000 miles, but sat for 30 years, so whatever is in there is hard as a rock.

Once I get the engine back together, I can start in on the rest of the bike.

So if I have to remove the transmission outer cover, can I get to the case bolt without disturbing the transmission too much?

Thanks!

I would also leave the cams and gears alone, replace the rod bearings and check the main bearings close but they should be good. Sludge trap is pretty easy to clean but I would order a new cap bolt for it as you may mess up the current one getting it off.
Set the engine on its left side remove the outer shifter and kick start cover (your case a kick start cover) then mark the shifter selector on the inner cover in its current position so it goes back the same. The inner cover has a phillips screw located towards the back and I believe 2 bolts on the front. Be careful and tap the cover loose so the gears don't move around and watch for a shim that may stick to the inner cover.
Once the inner cover is off you will see a large bolt and a large nut, those are what needs to be removed to split the case. No hidden bolts inside the transmission housing itself. Hope this made sense and I'm going from memory.

bagpiper22 · 12-02-2012, 07:46 AM

Sounds good. I got the inner cover off easily enough and removed the nut there (top right).

I put the cover back on for now, so I can split the cases without a hundred gears falling out. Once I have the case back together with a nice clean crank, I'll go back and remove the old gasket material and replace the case nut.

Sound about right?

marksbonneville · 12-02-2012, 07:49 AM

Quote:

Originally Posted by bagpiper22

Sounds good. I got the inner cover off easily enough and removed the nut there (top right). Sound about right?

And remove the bottom bolt below it. If the gears come out its not the end of the world, just a few gray hairs.

bagpiper22 · 12-02-2012, 08:25 AM

Success! Left side is off. Not bad at all.

Now I need to get the crank out. Pinion gear is still attached (no puller yet) so I'll pull the pinion with main bearing out of the case, then deal with it.

marksbonneville · 12-02-2012, 08:34 AM

Quote:

Originally Posted by bagpiper22

Success! Left side is off. Not bad at all.

Now I need to get the crank out. Pinion gear is still attached (no puller yet) so I'll pull the pinion with main bearing out of the case, then deal with it.

Looking good, my sludge trap was not that bad but I felt better knowing it was clean.

bagpiper22 · 12-02-2012, 06:08 PM

I'm the same way about the trap. I don't expect much in there, but since I had the engine apart for new rings anyway, I figured I might as well put it back together all nice and clean.

I got the bike last year after it sat for 30 years in a closet of the local high school auto class. It will be a blast to hear it run. Maybe by spring...

Thanks for all you help!

marksbonneville · 12-04-2012, 02:45 PM

Quote:

Originally Posted by bagpiper22

I'm the same way about the trap. I don't expect much in there, but since I had the engine apart for new rings anyway, I figured I might as well put it back together all nice and clean.

I got the bike last year after it sat for 30 years in a closet of the local high school auto class. It will be a blast to hear it run. Maybe by spring...

Thanks for all you help!

Curious to hear how bad the trap is. Your bike looks great, I really miss having a Triumph and hope to find another one someday, maybe a 500 twin.

bagpiper22 · 12-04-2012, 03:12 PM

I'll let you know what I find. I had to leave it half-opened for now. I did what I could to remove the pinion gear, but didn't want to force it, so the proper tool is on the way. Should arrive this week.

I moved too fast and didn't mark my shifter before pulling the inner cover, so now I'll learn all about indexing. fun fun!

I hope to get at the trap this weekend. Will post results.

Thanks!

Scott

06-17-2012, 02:40 PM	#33
marksbonneville ^OP Studly Adventurer Joined: May 2008 Location: Arizona, Prescott more less. Oddometer: 937	She Runs Again Had a hell of a time diagnosing a bad fuse holder but once that was replaced she started right up and runs fantastic. http://www.youtube.com/watch?v=Jo2q5...ature=youtu.be

12-02-2012, 06:45 AM	#37
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	Yes...shop manual and exploded parts diagrams on hand. I'm not planning on removing the intake and exhaust timing gears. Just the center gear which slides right off. Everything else seems intact there. I'll be sure to line up the timing marks when I reassemble. My goal is the sludge trap. This bike only has 7000 miles, but sat for 30 years, so whatever is in there is hard as a rock. Once I get the engine back together, I can start in on the rest of the bike. So if I have to remove the transmission outer cover, can I get to the case bolt without disturbing the transmission too much? Thanks! bagpiper22 screwed with this post 12-02-2012 at 07:29 PM

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12-02-2012, 05:29 AM	#34
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	Great thread. Thanks. I'm about to open the case on my 76 Bonnie, and I'm getting all the input I can before I do it. Primary drive and clutch is off, gearbox cover off, etc. Quick question: there were differing opinions, but no clear answer: was there a case bolt behind the inner cover, or were you able to split the cases with transmission in place? Like you, I'm trying to get the crank out, while disturbing as little else as possible. I'm also having a time with the pinion gear. I've read you can heat the case in an oven then remove the crank with pinion and main bearing in place. Is that what you did? I'll probably get the proper tool, but if there's something I can try in the meantime that won't hurt the engine, why not? Lastly, I love the T140 pedestrian slicer license on the front fender in the video. Where did you get that? Thanks again for the post, and everybody's replies. Scott

12-02-2012, 06:40 AM	#36
marksbonneville ^OP Studly Adventurer Joined: May 2008 Location: Arizona, Prescott more less. Oddometer: 937	I did remove the transmission assembly but I could have removed the inner cover, removed the two bolts holding the case together and re installed the inner cover. Putting the transmission gears back was a challenge but in the end worked out ok. The other thing I learned was I did not need a crank pinion gear puller, I removed the crank and used a press, I spent a bundle on a pinion puller that did not do the job and was junk. A repair manual will be needed but you can find online copies. Hidden bolts???? hmm let me see how good my memory is.... lifter bolts inside the crank case, front stud used for the exhaust brackets, a screw is kind of hidden that hold the inner transmission cover......I may be missing something. I picked up the pedestrian slicer back in '88, always gave her that special look. After 25 years I sold the Triumph, tools, and manuals this last summer, great bike just was time to move on.

12-02-2012, 07:46 AM	#39
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	Sounds good. I got the inner cover off easily enough and removed the nut there (top right). I put the cover back on for now, so I can split the cases without a hundred gears falling out. Once I have the case back together with a nice clean crank, I'll go back and remove the old gasket material and replace the case nut. Sound about right?

12-02-2012, 08:25 AM	#41
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	Success! Left side is off. Not bad at all. Now I need to get the crank out. Pinion gear is still attached (no puller yet) so I'll pull the pinion with main bearing out of the case, then deal with it.

12-02-2012, 06:08 PM	#43
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	I'm the same way about the trap. I don't expect much in there, but since I had the engine apart for new rings anyway, I figured I might as well put it back together all nice and clean. I got the bike last year after it sat for 30 years in a closet of the local high school auto class. It will be a blast to hear it run. Maybe by spring... Thanks for all you help!

12-04-2012, 03:12 PM	#45
bagpiper22 Adventurer Joined: Jun 2012 Location: Norwalk, CT Oddometer: 18	I'll let you know what I find. I had to leave it half-opened for now. I did what I could to remove the pinion gear, but didn't want to force it, so the proper tool is on the way. Should arrive this week. I moved too fast and didn't mark my shifter before pulling the inner cover, so now I'll learn all about indexing. fun fun! I hope to get at the trap this weekend. Will post results. Thanks! Scott