Middle Gear

[Cdnlouie]

Originally it was stated:

 

"From my perspective, there seems to be a lot of "play" somewhere and I have a whining kinda noise coming from somewhere down there during deceleration. By "play" I mean that when the bike is on the centerstand and it's in first gear, I can rotate the tire forward and back to what seems to me to be excessive. I can tell by doing this that the free play is at the engine end. Thought maybe there might be a shim issue or something. I'm pretty certain it's not u-joint related tho."

 

 

This "excessive play" you are mentioning is normal on the Venture. It does seem alarming, and you are right that it is seems to be up in the engine. This play is on the main drive axle, which is why the manual states you need to hold the drive axle nut (behind left middle gear cover with special tool) when you check the middle gear drive lash. It rotates freely on the drive axle for a significant degree of rotation (not sure how much is normal), which adds quite a bit of "play" at the rear wheel.

 

You can't eliminate this free play by checking middle gear lash, as that is virtually insignificant compared to the free play in the middle gear pinion (which is set against the gear set of the main drive axle). Check the parts diagram and you can see that the middle gear set rotates against a spring and pivot arm that allows for this free play. You would need to have the engine apart to check for wear at this point.

 

I have an article on this problem in the general tech section (rear output shaft breaks off nut) as I am currently replacing my output shaft on mine and have looked into this problem.

[SilvrT]

Why are you in need to replace the Seal ?

 

I never did that and it always worked fine for me.

 

The seal looks quite worn so since it's out, might as well replace it... what can it hurt? Also, since I have now totally screwed it up removing it from the shaft, I HAVE TO!

 

LOL

[SilvrT]

Guys, please note that the 83-85 and 86up differentials are completely different. There is some confusion going on here. The 83-85 is the only one in which you pull the shaft out of the pumpkin. the later model which is the one here is part of the pumpkin.

 

This "excessive play" you are mentioning is normal on the Venture. It does seem alarming, and you are right that it is seems to be up in the engine. This play is on the main drive axle, which is why the manual states you need to hold the drive axle nut (behind left middle gear cover with special tool) when you check the middle gear drive lash. It rotates freely on the drive axle for a significant degree of rotation (not sure how much is normal), which adds quite a bit of "play" at the rear wheel.

 

You can't eliminate this free play by checking middle gear lash, as that is virtually insignificant compared to the free play in the middle gear pinion (which is set against the gear set of the main drive axle). Check the parts diagram and you can see that the middle gear set rotates against a spring and pivot arm that allows for this free play. You would need to have the engine apart to check for wear at this point.

 

I have an article on this problem in the general tech section (rear output shaft breaks off nut) as I am currently replacing my output shaft on mine and have looked into this problem.

 

Thanks for this feedback and I have been following that article to some degree...possibly missed some of the info in it.

[Squeeze]

Guys, please note that the 83-85 and 86up differentials are completely different. There is some confusion going on here. The 83-85 is the only one in which you pull the shaft out of the pumpkin. the later model which is the one here is part of the pumpkin.

 

 

Originally it was stated:

 

"From my perspective, there seems to be a lot of "play" somewhere and I have a whining kinda noise coming from somewhere down there during deceleration. By "play" I mean that when the bike is on the centerstand and it's in first gear, I can rotate the tire forward and back to what seems to me to be excessive. I can tell by doing this that the free play is at the engine end. Thought maybe there might be a shim issue or something. I'm pretty certain it's not u-joint related tho."

 

 

This "excessive play" you are mentioning is normal on the Venture. It does seem alarming, and you are right that it is seems to be up in the engine. This play is on the main drive axle, which is why the manual states you need to hold the drive axle nut (behind left middle gear cover with special tool) when you check the middle gear drive lash. It rotates freely on the drive axle for a significant degree of rotation (not sure how much is normal), which adds quite a bit of "play" at the rear wheel.

 

You can't eliminate this free play by checking middle gear lash, as that is virtually insignificant compared to the free play in the middle gear pinion (which is set against the gear set of the main drive axle). Check the parts diagram and you can see that the middle gear set rotates against a spring and pivot arm that allows for this free play. You would need to have the engine apart to check for wear at this point.

 

I have an article on this problem in the general tech section (rear output shaft breaks off nut) as I am currently replacing my output shaft on mine and have looked into this problem.

 

Sorry Cecil, but i have to oppose your Statement.

 

I don't know nothing about the early Pumpkins and their Drive Shafts, but the later Pumpkins have taken place in a Lot of Bikes (FJR,Vmax, 2Gen and who know where else) in different minor Variations. Whenever i was in need to put a Pumpkin back in Place, i've always pulled the Shaft out of the Pumpkin and never did anything go south.

 

Even the Workshop Manual for the later 1Gens and the Vmax states that the Shaft is mounted to the U-Joint prior to the mounting of the Pumpkin. In your Theory this couldn't happen, because the Shaft is mounted to the Pumpkin. Maybe you have the early and later Pumpkins mistaken ?

 

Second, regarding the free Play inside the outbound Shaft of the Transmission.

There is none. There can't be any free Paly. The Spring load on those two Cams inside the angled Gear is heavy. That is why you need a Shop Press or other high Force Tools to undo the C-shaped Washers which hold everything together. If there would be any Lash or free Play, this Safety Clutch would unlock every second Time you accelerate a bit harder. You would feel and hear this 20 Meters away from the Bike. I've been there and i can tell you this is a hammering Noise you won't forget your Lifetime. I had the big Ball Bearing partly damaged and it locked up on every 10th or 20th Revelation of the Motor. It was all my Fault and i payed the Price for it. No need to ask how come ... :whistling:

 

So, if you grab the the big Nut on the outside of the middle Gear and the U-Joint with the other Hand, you can feel the Lash between both angled Gears and the Lash in the Spline of the U-Joint. If there is a Lash in the Spline. When playing around, you can feel and determine which is which Lash. Of Course, if someone is technically inclined he can get a satisfying Result much quicker.

[Cdnlouie]

Hi Squeeze,

 

You are correct about being able to remove the driveshaft on the 86up and my intention was to differentiate between the two as the 83-85 just pulls out, whereas you have to contend with the seal on the later model. My apologies for giving the wrong impression.

 

Re: the free play in the drive axle gear set. I totally agree with your description for checking the middel gear lash, my point is that the main drive axle does rotate freely (you are correct about the spring tension on the cam that is not moving).

 

I am not sure where the play is (somewhere along the main drive axle connections toward the clutch and primary gear), but when you look in the back of the engine (output shaft removed) you can turn the pinion gear (with the cam and spring on the main axle) for a significant amount of rotation. This translates into significant free play through the middle gear set and back to the rear wheel. This is why you must isolate the gear on the left side of the engine to check the gear lash in the middle gear set (as you described).

 

Thanks for your feedback,

 

 

 

[SilvrT]

Dang... the feedback and technical info here is awesome! Some good info to include in a "How To" book.

[Squeeze]

Cecil, now we are on the same Page.

 

The "Freeplay" or "Lash" is caused by the Transmisson Gears.

 

In Fact i think we can't call it that Way, because this is none of the mentioned.

 

It is the Distance of traveling which the Dogs travel free in the Gears. These Dogs allow some Travel within the Gear which it is connected to, whenever the Trans is in a Gear. This is inherent in such Kind of Transmission.

[Dano]

Ok, finally got my hillbilly work table together and got the motor up there (don't ask me how!). Pulled the side plates and I have about 1/8" movement in the ujoint when holding the middle gear nut. I can feel the teeth touching each other when I move the joint. Re-collar and re-torque?

[Squeeze]

Can you see the U-Joint moving behind the Nut ??

[Cdnlouie]

I don't mean to hi-jack this thread (from SilvrT), but I wanted to say that I finished installing the new expansion collar on the driven pinion output shaft and I have ended up with too much free play in the bearings (in my opinion, after torquing to 65 ft. lbs and installation).

 

As I mentioned in my other post the new collar is 1mm wider than what was in the previous two engines (I am assuming wear - 10.3mm compared to 11.3mm for new collar). Now after torquing the shaft nut to 65 ft. lbs (nice and slow), there is just too much free play in the two tapered bearings (one on each side of the output shaft housing to steady the shaft). I have no measurement from the manual for this (except the procedure) and no way of knowing what is normal or allowable (except, call it intuition).

 

I have been checking the lash with a micrometer (after installing it) and it is hard to check the rotational lash with the additionnal slop in the bearings (it was hard to tell what was normal until you got it mounted back in the engine). At this point the only thing I can do is remove the collar and shave some of it off to be slightly bigger than the worn ones I took out and then re-torque. I don't want to overtorque as crushing the expansion collar is probably not a good idea.

 

I am wondering if I am missing something here?

[SilvrT]

I don't mean to hi-jack this thread (from SilvrT),

 

no problemo ... it's all good info

 

[Dano]

Can you see the U-Joint moving behind the Nut ??

 

No, the ujoint and nut move as one, I can feel the teeth touching each other when you rock it back and forth. I believe it's still tight, might just be the lash between the middle and pinion gear. I'll look closer when I finally get her opened up this weekend.

 

Thanks,

 

Dan

[Cdnlouie]

Re: I am copying my post from "Rear output shaft breaks off nut" for your information here. I agree with Squeeze if the yoke does not move behind the nut your shaft is tight (I would probably be content with leaving it). The only other thing to check for would be having the proper bearing preload as described below.

 

Post reads: Okay, I think that the picture is beginning to come together for me (no thanks to the Yamaha manual).

 

This is my first experience with pinion gears and I was much perplexed by the "standard starting torque" which is stated in the 1st generation manual. I knew it had to be related somehow to the bearing preload, but could not make the technical connection (this is the torque necessary to keep the bearing moving). This is described in no detail in the 1st gen. manual and what is there, is puzzling at best.

 

Apparently, the collapsible collar (expansion collar) works as a spring (it has a rounded centre or half-circle) that bends under tightening until you get your correct bearing preload (more precisely - spinning torque). This does not mean the collar is collapsing, but it is bending which is an important distinction (not described in 1st gen. manual).

 

The new collar is 11.3 mm wide and it does bend down to about 10.3 (which at this point would probably not have its proper bearing preload). The proper procedure requires that you complete this process without overtightening the collar, as it does not spring back or you must replace the collar and try again (a one way process).

 

This whole procedure pretty much demands that you replace the collar when you replace your rear seal, since once you remove the output shaft nut you need to start the bearing preload process all over again or else you cannot be certain you have the correct "spinning torque" (or starting torque) on your output shaft (once you have put the universal yoke back on).

 

The 65 ft-lbs stated in the manual (for the yoke nut) really has no bearing on how tight your yoke nut should be, it just gives you a starting idea of how much effort you need to apply (first time I have ever seen that).

 

After you have tightened the yoke nut (in small stages) you must use the proper torque wrench (this is the key here as it has to be a very delicate instrument) to measure the .4-.5 Nm or .29 -.36 ft-lb of "starting torque". Most likely a beam type torque wrench that will register accurately this small amount of pressure required to keep the bearing (with the torque wrench on the yoke nut) moving (or rotating in the housing). This records the ever so gentle drag on the bearing, and I assume that this drag is measured by gently pushing against the torque wrench with a couple of fingers for about one revolution to see if the torque remainds within these specs throughout the revolution.

 

Additionally, I would think that the bearing should be oiled rather than dry which would probably affect the torque reading.

 

This is all I can figure out about the process, now I will have to give a try.

---

[Dano]

Thanks, I'm going to check the wear pattern on everything when I disect the bottom end. This is fabulous info, I appreciate the time you've taken researching this. Very thorough and the posts discussing it has been like a lecture series on this area.

[Cdnlouie]

An update on this journey of learning:

 

Here is my understanding of how to properly torque the rear output shaft after you replace the seal and inner collapsible collar (and maybe bearings if necessary)

 

When I installed the new collar (on the output shaft between the two tapered bearings) it took up to 85 ft-lbs to get it moving to take up the bearing slack (manual indicates 65 ft.lbs.). This seems to indicate that the new collar has much greater strength than the old one. They may have improved these in later models, or the metal fatiques over time and it looses its "spring tension" capability. It works like an old car "leaf spring" and we have all seen them fatique over time.

 

Here was my installation technique:

 

I did have to bring the torque wrench up to 85 ft-lbs in order to get the collar to begin collapsing, in order to take up the bearing slack. I tightened the nut very incrementally. I started with about a quarter turn (to get it moving) and then reduced it to only about 1-2 degrees each time. Basically just feeling the nut barely move until I had taken up any bearing play (no discernable wiggle in the housing), turning the bearing (several times) and then checking again after about 360 degrees.

 

Once the play was gone, I marked the nut location according to the washer underneath with a marker and then just barely moved the nut in 1mm increments (a clockwise rotation measurement according to the nut and washer marks) for about 9-10 mm (from the zero bearing load position) and bearing load felt sufficient (mechanic's intuition here) at this point. As you can see it did not take very much movement to get up to a reasonable (in my opinion) bearing load. In the ideal world a torque wrench measurement would be perfect (.29 -.35 ft.lbs according to manual).

 

I then installed the universal joints and the shaft back into the engine and set the gear lash to .003 with the original shim so I did not need to change anything and it came back to perfect factory specs (.002-.004). It sure feels good when something goes right.

Now I am replacing my swingarm bearings while I have it apart as they are definitely worn and that will be a nice little winter project brought to completion, just in time for spring.

 

Cheers fellows

 

P.S. I will post a follow-up once the snow clears and it am able to do a road test).

[SilvrT]

The seal looks quite worn so since it's out, might as well replace it... what can it hurt? Also, since I have now totally screwed it up removing it from the shaft, I HAVE TO!

 

LOL

ahem!!!.... back to the original topic for a minute... I got the new seal on and was able to slip the driveshaft back into the U-joint splines with about 3 tries even tho the splined end of the U-joint was laying over to the bottom side a bit.

[paysaw]

Has anyone come up with a shade tree way of setting up the middle gear lash?.I had to pull my middle gear again because of a leak I had it the gear bearing seal.I replaced the middle gear unit but would like to take the time to set the lash with the shimms.Thanks. Ray

[friesman]

geez and rocket just rode by there yesterday..........pm him as he is online even when he is travelling. i think he is Colbourne on right now...

 

http://share.findmespot.com/shared/faces/viewspots.jsp?glId=0dW2uviFRmfVBIi65A9vRaQ1osJHe2jOq

Brian

[scottbly]

Pardon my ignorance if this is completely off subject, but I am paranoid about my 83 Venture's 2nd gear. If the punch mark indicator referred to in other threads is true, my 83 with 40,000 miles has not been retrofitted for the dreaded 2nd gear. I have an 84 parts bike with 50,000 miles that has been punched. If the 2nd gear starts to go on my 83, what is the easiest / cheapest way to fix? Can I "simply" separate the engine and transmission with the drive shaft, pumpkin, etc. in one piece, then replace with the same "assembly" from my parts bike? Thanks

[SilvrT]

Pardon my ignorance if this is completely off subject, but I am paranoid about my 83 Venture's 2nd gear. If the punch mark indicator referred to in other threads is true, my 83 with 40,000 miles has not been retrofitted for the dreaded 2nd gear. I have an 84 parts bike with 50,000 miles that has been punched. If the 2nd gear starts to go on my 83, what is the easiest / cheapest way to fix? Can I "simply" separate the engine and transmission with the drive shaft, pumpkin, etc. in one piece, then replace with the same "assembly" from my parts bike? Thanks

 

"Simply" put... yes ... but in reality, I believe you have to pull everything apart including taking the engine out so once you're at that stage, might as well FIX it with new parts (if you can still get them). Several others here on the site have done this and can assist.

 

BTW, you might get better response to this by starting a new thread as this one is pretty old and your Q is off-topic somewhat.

[dingy]

Pardon my ignorance if this is completely off subject, but I am paranoid about my 83 Venture's 2nd gear. If the punch mark indicator referred to in other threads is true, my 83 with 40,000 miles has not been retrofitted for the dreaded 2nd gear. I have an 84 parts bike with 50,000 miles that has been punched. If the 2nd gear starts to go on my 83, what is the easiest / cheapest way to fix? Can I "simply" separate the engine and transmission with the drive shaft, pumpkin, etc. in one piece, then replace with the same "assembly" from my parts bike? Thanks

 

Only way to fix it is to pull motor from bike, split case in half & replace thrust washer & any other damaged parts.

 

If it is jumping out of gear, you may need gears and possible shift fork.

 

If your asking, can you swap motors, the answer is yes. They are a direct swap.

 

Gary

[scottbly]

Thanks, but I wasn't looking at changing the whole motor, I was think of leaving the motor in the bike as swapping the transmission, drive, swing arm, etc as one piece. Does the transmission separate like a car does? Thanks again.

[dingy]

Thanks, but I wasn't looking at changing the whole motor, I was think of leaving the motor in the bike as swapping the transmission, drive, swing arm, etc as one piece. Does the transmission separate like a car does? Thanks again.

 

Transmission is built into motor. Split case is only access.

 

Gary

[scottbly]

OK. I get it now.

[SilvrT]

OK. I get it now.

 

There's simply no "simple" way around it ...