Jump to content
IGNORED

Hey RandyA, Time to do second gear.


fixit3546

Recommended Posts

Today I had to put one of the pins back in my shift drum again. This is the third time in as many weeks. This time the metal tab that bends over the pin broke off, So i welded the pin to the plate, ruined it for future repairs; but it works for now. (every shop needs a small mig welder). I think that when i miss third and land in second gear it is some how causing pressure enough on the shift drum to push the pin out, I don't understand this happening; but something is doing it and it is always after landing in second. it could be that it has something to do with the shift lever being out of adjustment ( heel to toe shifter) causing me to land in second.

All this aside, it's time to do a second gear job and a shift drum repair.

 

I have aquired a donor bike/motor so i will be pulling the tranny from it as soon as i finish anpther job i'm doing so it may be a week or so.

 

I plan to make repairs along the line of the repair that randy has made to his. So Randy I'm looking for all the info you have. I am posting a picture of the tranny for reference, If i am understanding your previous posts. The location i will be working on is shaft #1 and gear set #5 which is the second gear pinion. Is #10 the washer you fliped over ? and tell me again about how you cut the dogs on the side of the gear. I think you said that you cleaned up the wear by flatening out the wear on the end of the post which caused a little slack in the gear set but wasen't enough to really notice. then you cut out .020 from the dog, my question here is how did you shape the dog. Is it a slope with the .020at the base, or is it more of a hook or notch shape?

Link to comment
Share on other sites

  • Replies 58
  • Created
  • Last Reply

Top Posters In This Topic

Just wanted to bring it back up, i'll be posting some picts of the engine removal and tear down (from the donor bike) as soon as i have a chance to do it. By the way, I have a few parts that will be avaliable soon, the bike has been pretty much stripped but a few parts remain.

Link to comment
Share on other sites

James, Without getting into a lot of detail tonight, I will try to run thru the basics of what I did.

After getting the gear set apart and determined which gears were affected, I used the following;

A Dremil grinder, digital calipers, a 1/8th inch radius Gage, good 1/4 inch grinding stones and some good close up reading glasses and a lot of patience.

The 1/8th inch radius gage fits the contour on the ends of the dogs. When removing material, you will need to use the radius gage to determine that you are maintaining the correct contour.

The first thing to do is measure the length of each one of the dogs to make sure they are the same. Mine were with-in .001 of being the same on each and from top to bottom. I clamped the gear in a workmate vise as it gave a good working platform to work off of. I then started removing material from the front of one of the dogs, making sure that I was keeping the same contour. I did this until I had removed enough material to bring the corner back to a sharp edge. When I was satisfied that the first dog was about where I wanted it(no undercut at this point), and the contour was centered when looking at it from the top to the bottom using the radius gage, I then started on the next dog. I did the same with it, but I also took into consideration that I wanted the overall length to be as close to the first one as I could get it. Then the same for the last dog.

If, in removing material from the 2nd and 3rd dog you take a little more off than you did on the first one, then the dog that gives you the smallest reading in length becomes the target. Once you are satisfied you have the dogs the same length, it is time to start the undercut material removal. By tilting the axis of the grinder you will need to start taking material off of the foot of the dog. The trick here is to remove material, still maintaining the same contour and not removing material from the top corner, but blending right up to where the edge is. What you will need to do is use the calipers and measure several points from top to bottom. Since I did this about eight years ago, I don't remember exactly how much material I removed to get the undercut, but it was probably in the .015 to .020 range at the bottom point. I don't think the amount or angle is that important, but all three dogs need to be as close to each other as you can make them. This would be with taking reading at the top, half way down and at the bottom.

What you also want to do is determine as best you can what the approximate angle you have on the grinder when you have contact from top to bottom with the grinding stone to the leading edge of the dog, and this would be with a good grinding stone.

OK, at this point you have removed material from the leading face of all three dogs and the measurements from each are as equal as you can make them and the contours fit the 1/8th inch radius gage from top to bottom and the contour is centered. Ya done good.

Now it is time to start on the female side, or the matching gear with the slots on the side. On mine, I was lucky that the corner on the contact point on the top edge was still sharp. It was not rounded off like the leading edge of the dogs were. Now, remember the angle that you used to remove material when you were tilted some with the grinder? You will need to use this same tilt to slightly more. What you are doing now is giving some relief. You will want to tilt the grinder and start removing material on the end of the slot without touching the top corner. This would be with a good 1/4 inch grinding stone. The stone will fit the slot good so you will need to make sure the material being removed is centered and you don't allow the force of the grinder to pull it off center.

Unless you have some small telescoping gages and a micrometer to measure at different points from top to bottom on the slot, you will just have to visually try to make the slots the same and have the angle as close to the same on all three slots. You can do this because you still should have the top corner of that end of the slot still not ground on, but blended up to it.

OK, the gears are done, what next? You will absolutely want to replace the thrust washer as the new ones are harder and thicker. The thicker part causes the dogs to be inserted deeper into the slots than they were originally.

The next major consideration will be the forks. Mine were bent and I am pretty sure yours will be too. They get bent when the dogs climb out of the gear and cause a lot of pressure on the forks. What you will see is score marks on the center of the forks at the bottom on one side and on the tips of the forks on the other side. You should also be able to see that the forks are not parallel in the slot of the gear. I remember that I used a reference point on the casing and I could measure the difference in the forks from the ends to the bottom. I used a small piece of pipe over each fork end to pull that back to where they needed to be. It was a bit tedious but not too difficult. You will notice when you put the gear set back in that the forks fit the slot much better from the bottom of the fork to the ends of the forks.

I belive with this as a basis and gaskets and oil that you should have a long life with this transmission and at very little cost to fix it. I know there will be some that would not take this thing a part with out repalcing everything and that is great, but I did not want to spend that kind of money and don't believe it is absolutely nesessary.

When you get into this thing, please keep me posted. Any questions that you have I will try to answer.

randya

Link to comment
Share on other sites

Couple of pictures of the donor bike and donor engine.

 

Randy, thanks for the right up. If i am looking at the gear sets right, I don't see any wear on the 2nd. gear dogs and they may alteady have some angle cut into them, I'll have to borrow a set of calipers from work and check it out.

I'm wondering if the problem has already been repaired. I do not see punch marks on the underside of the case at the shifter shaft. the odometer of the donor bike had 38000 miles on it.

 

Any specific picts anyone ??

 

Don, I have something for you if you will e-mail me your addresse.

 

I still have my bike to take apart, I'll try to get more picts on that project. and of the case separation.

Link to comment
Share on other sites

  • 1 month later...

Today I decided to get out there and get busy.

I pulled the trans gears and shafts from the donor motor. Assembled it alltogether in the lower case and started turning the shaft and working it through the gears. After seeing how things worked i pulled the drive axle out, this is the shaft with the problem. I pulled all the gears off with the exception of the second gear wheel. it is held on with clips. I had no reason to take it off at this time.

 

The problem, i found, is with the dogs on the 5th. gear wheel which has the dogs built onto the side of it to engage the second gear. Just as randy described, it had a fair amount of wear on it. also the retainer clips that hold the pinion gear on had a grove cut in them. (is this the thrust washer i keep hearing about ?)

 

The width of the posts was about .485ths. I ground them down to a flat .463ths. and cupped them to about .457ths.

 

I quit for the night. Tomorrow I will clean everything up and bag the transmission untill I have all the parts i need to do the job and a little time.

 

BTW, I built a very simple press to remove the pinion gear.

I used two 16"x3/8" allthread rod and nuts.

I used a peice of I-beam that use to be the tongue of a trailer and cut two holes in it about 5" apart for the bolts to pass through. that made up the base. for the working end, I cut the center out of an old "doughnut spare" wheel that was on a dodge car. I cut the bowl out of the middle of it, cut one small hole between two lug bolt holes for my allthread to pass through, (i used a lug hole on the other side.) then I had to open the middle up a just a bit. It worked by compressing the shaft between the the two pieces as the nuts were screwed down on the allthread. the end of the shaft rested on the plate and the "wheel" end compressed the spring sending the shaft up through the hole untill the retainers could be removed.

 

I'll try to get a photo next time, I,m not much on wrighting technical articles.:confused24:

Link to comment
Share on other sites

First of all James, it sounds like you are on track. Yes, the clips that hold the gear set together is what I turned over. It is MY understanding this is what works as the thrust washer. I will try to get my repair manual out tomorrow and see if I can jog my memory a bit better. Like I said earlier, I did this about eight years ago.

I am a little confused with some of your terminology, such as grinding the post down flat and cupping them. To me, you would be removing material from the leading edge of the post/dog until you have a sharp corner, then removing material from the bottom of the dog, blending it up the sharp corner to create the undercut.

randya

Link to comment
Share on other sites

The photos are pretty self explanitory, the 5th. gear wheel has the dogs on the side that mate into the 2nd. gear wheel to conect power to the driven shaft.

 

The home made press dosen't look like much; but was very effective.

 

One of the photos shows the work done on the dogs. don't know if it will retain much detail after resizing.

 

After reasemblying it all back in the case, i noticed that the dogs engage the 2nd gear wheel about 1/8"-3/16" Didn't look at it before hand.

Link to comment
Share on other sites

James, what does the fork look like? Can you see score marks on one side at the bottom and on the other side at the fork tips?. Also, when you set the gear set in place with the forks in place, see if the clearances are the same at the tips VS the base. Does that make sense? Did you replace the split washer?

Randy

Link to comment
Share on other sites

This is a fantastic discussion. If you two could put this together in a tech type article it would be great for the first gen tech library. If you decide to do so, just put it together in html format or even in Microsoft Word format or any way you want to. I can make it work from there.

 

Don

Link to comment
Share on other sites

Thanks Don, I appreciate the comments. I think what James or I need to do is get a couple sets of gears and set up a gear-set rebuild. This would include the gears being undercut and the thrust washer being replaced and then reassembled. With doing this and then putting together a tech article or use the one already written, a person with some mechanical understanding and some help could pull the engine, turn it upside down and split the case to the gears. The gear set could be pulled out and the rebuilt set could be set right back in. The worn set could then be sent back to be rebuilt for someone else. And the recycling could go on.

I feel this could be a real feasible program and help some of these guys get their bikes fixed for a minimal cost. The only other concern would be dealing with possible bent forks. They are fixable, as I did mine, but it could be a little tricky. At this moment I do not remember what it would take to replace the fork. Maybe James can give us an update on this. The other option would be to replace the fork as part of the rebuild.

I think this is a program we should really pursue. There are just too many early 1st gens that are really nice bikes with probably 200,000 miles left in them if the transmissions were fixed.

What do you think James?

randya

Link to comment
Share on other sites

Sounds good to me Randy. It may be after the first of the year before i get to get into the running bike. just too much going on right now. but if things come together sooner, I plan to post picts of the tear down.

 

And I'm not too bad stuck on myself, In other words this aint my article. Use it, add to it as you see fit. Everyone here deservs this info.

Link to comment
Share on other sites

  • 1 month later...
  • 2 weeks later...

Hope I got everything in order here, This is a shortened version of the shop manual procedures.

 

 

Removing the Venture Engine.

 

It is suggested that the engine be cleaned before removal, And that the proper tools are on hand.

 

[Note: When disassembling the engine, keep mated parts together. This includes gears, cylinders, pistons, bearings and other parts that have been “mated” together through normal wear. Mated parts must be reused as an assembly or replaced.]

  • I used zipper seal snack bags to keep bolts for different parts and covers together so I wouldn’t have to search for the right one later.

  • I used plastic dish pans to keep my parts in order and gallon zipper seal bags to store the clutch assy. And the oil pump.

  • I should have drained the oil before I removed the engine, (Must have been sleeping)

 

Removal

  1. Place the bike on the center stand, on a sturdy foundation.
  2. Remove side covers, false tank cover, and fairing. Remove the breather. The question was asked about the tabs breaking. I don’t know what to do about that, the first gen bikes have age and that is hard to avoid. Use care with them and use Vaseline on the side cover rubbers to lubricate them.
  3. Remove the crankcase vent hose.
  4. Remove the choke cable from the carbs.
  5. Disconnect the throttle cables at the middle connector. (don’t know it’s proper name)
  6. Remove the carburetors from the left side.
  7. Stuff clean rags into the intake boots to keep things out of the engine.
  8. Disconnect the YICS hoses. I left my coolant hoses connected to the engine.
  9. Remove the spark plug boots.
  10. Remove the YICS chamber.
  11. Remove the air baffles located on the top of the cylinder heads.
  12. Remove the radiator covers and horns.
  13. Remove the hoses from both sides of the radiator. Loosen the hoses on the bottom of the radiator.
  14. Remove the radiator being careful not to perforate it!
  15. Remove the Engine guards.
  16. Remove the footrest and break petal.
  17. Remove the right side engine cover plate.
  18. Remove the brake master cylinder bolts and the brake fluid reservoir mounting bolts.
  19. Remove the left footrest and shift pedal.
  20. Remove the middle gear case cover and the lower left engine cover.
  21. Remove the rear shock absorber damping adjuster screws.
  22. Disconnect the Generator lead, neutral switch lead and the pickup coil lead.
  23. Remove the shift arm from the shift shaft.
  24. Remove the clutch release cylinder.
  25. Disconnect the drive axle boot and spring.
  26. Disconnect the front headers from the cylinder head and the chamber and remove the headers.
  27. Remove the mufflers.
  28. Disconnect the exhaust chamber from the bottom of the engine and disconnect the rear header clamp.
  29. Disconnect the starter motor lead and the ground lead.
  30. Remove the thermostat housing and the starter.
  31. Remove the oil filter housing.
  32. Remove the front upper engine mounting bolt and the side frame tube.
  33. Place a floor jack under the engine and remove the front and rear lower engine mounting bolts, The right lower frame section and the front frame cross tube.
  34. Remove the engine from the right side (You are going to want some help here)
  35. The valve covers can be removed to give additional clearance.
  36. MAN WHAT A JOB !!!

I wanted to add some picts here but when my computer crashed i lost them............I'll see what i can dig up.

Link to comment
Share on other sites

I used zipper seal bags and plastic dish pans to separate my bolts and organize my parts as i tore the engine down. A permanent marker works well on the bags to mark where the bolts go.

 

If I can remember this right............

 

  1. Remove the clutch cylinder, the alternator cover and the starter gears.
  2. Remove the water pump.
  3. Remove the clutch cover and the clutch.
  4. Remove the bearing retainers on the final drive and under the clutch
  5. Remove the oil pump drive gear,
  6. Removed the upper case bolts on the rear of the engine and the engine ground bolt. there are three bolts under the rear cylinders that will not come out if the head is not removed. unscrew them and leave them there.
  7. Turn he engine over.
  8. Remove the oil pan.
  9. Remove the oil pump and oil lines.
  10. Remove the crankshaft main bolts.
  11. remove the lower case bolts.
  12. Gently remove the lower case.

Everything I looked at in my transmission looked good except for the shift forks and the second gear dogs.

The forks have some pretty bad uneven wear and the dogs are rounded off.

 

I had to drill the heads off of the bolts holding my clutch cylinder on because they rounded out.

 

I am posting a few picts of the tear down. Are there other picts anyone would like ? They are not in any order.

 

photo 24 is a bracket they holds one of the oil lines, i have taken two of these off and they both bent.

Link to comment
Share on other sites

  • 2 weeks later...
  • 2 weeks later...

Well still no parts, they should be in this friday.

 

I have all my plastic repaired except for smoothing it out and paint. It'll be black this time.

 

I have cleaned up some of the rust that was started by battery acid and coated with a rust inhibitor and black auto touchup paint.

Link to comment
Share on other sites

Finally, my parts arrived. When I picked them up, I found that all the parts were in (as i was told) so i looked in the bag. the sales guy had checked in all the parts and said they were all there. good thing i looked in the bag!!! The main part i needed, the thrust washers that hold the middle gear together (also the major cause of the second gear problem) were not there. on further investigation, the owner and I found that the counter man had checked the part off on the order slip. I grew up with the owner of this place and i usually just pick up my parts, never asking questions. Had i done this this time, I probably would have been accused of loosing them and i probably would have thought i did. Always check your parts before you leave the store!

Sam probably got his butt chewed on pretty good after i left.

 

These things were finished today.

  • Replaced the star shaped retainer on the shift drum. My old one had a broken tab and the one on the donor motor had been beat on with a chissel or screwdriver. The torx head screw striped out so i had to drill the head off of it; but i had thought far enough ahead to have orderd a new one. I cleaned the threads with carb cleaner and assembled it with a little "blue" loctite.
  • I reassembled it all back in the engine case, again using "blue" loctite on the screws. Note: The shift forks are numbered 1, 2 & 3 they should be assembled in that order, form left to right, with the numbers facing the left (drivers side) side. I replaced the shift shaft seal before making this assembly.
  • rebuilt the clutch cylinder. It was fairly simple to replace the seals. the hardest part was discovering that the piston is one peice and that the piston seal stretches over the piston. (my shop manual did not point that out) The bolts that hold all this to the engine also stripped out(the heads, not the threads) I had to dril the heads off of the bolts here too.
  • I had planed to put the brushes in the starter; but i couldn't find it and it was getting too cold to work. I guess i need a better shop heated instead of a 1500w electric heater.

The pictures arent all that good. they show the new parts installed on the shift drum and the parts installed.

 

NOTE: Just a note to remember that the shell bearings that the crank shaft and ballance shaft ride on need to be treated with kid gloves, with care. thay are easy to damage and they need to be put back in the same location they came from if they are reused.

 

:)

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...