middle gear drive leaking

[uri gal]

Hello all

I have an oil leak on my 85 vmax

The leak is from the big rubber that connect the rear arm to the engine

So I believe that the problem is a bad oil seal in the middle gear drive

My question is – it is difficult to fix it ?

I know that I will not have to take out the engine, but I do need to take out the rear swing arm – o.k

After it – I now that there is three nuts that holds the oil seal – but I saw it only I a drawing
(for reference - oil seal - 93101-35085-00)

So….let’s say I took that three nuts out – from that step it will be easy to replace and put a new seal? There is no trike steps that need pullers, heating and rest of headraces?
:ummm:
Thanks

Uri

 

[wildweasel_pt]

Can't read it. Write in plain color letters. Background on tapatalk is white so yellow over white no can do

 

[Redbone]

It could also be the rear drive unit seal(s) which will run up the driveshaft and leak at the same rubber boot. I had the same issue last year and is a easy enough fix on a stock Vmax.

 

[wildweasel_pt]

Is the oil black? You can also have a leak in final drive and it's running down the swingarm to the boot. If it's the u joint seal you need to remove the hub with those 3 M8 bolts and you need to disassemble the Ujoint and undo the lock nut to press a new seal in. Without the proper tools it will be difficult to disassemble the Ujoint needle bearings. A press is recommended or a big vise

 

[uri gal]

yes the oil is do black

 

[uri gal]

in the drawing its look like the seal came before the bearing.. so I thought no pullers and special tools needed....

 

[1967vmax]

If I was you I would clean the area up to pin point the leak ,some even use baby powder to help find the leak, that side has several areas ,rubber gromets coming out of stator cover, mid gear cover or copper washer, shift shaft seal or the area you just said, good luck

 

[[email protected]]

You may be able to pry the seal out after removing the u-joint, yoke retaining nut, and yoke.

If not, you will need to get the pinion gear out of the output shaft carrier. I used a 3 jaw puller to push it out. Surprisingly, it did not take much force.

Either way, be careful when tightening the pinion nut. The is a crush collar in the output shaft that sets bearing preload. If you tighten it too much, you will need to disassemble and replace the collar. Too little and you will have play in the output shaft. Its a good idea to pay attention to force required to turn the pinion gear by hand before you loosen the nut so you have something to compare to when you reassemble.

 

[uri gal]

So...
If i will slacken the crankcase bolt on each side of the middle driven gear (two bolts) and than unscrew the three bolts securing the middle driven gear, and than take out the shims... from this step could i just push out the unit ? (Without any forces or tools)

While i will have this unit in my hands, its will be easy to replace it with used one or get some help from friends to rebuild it.... but i need that unit out.
When i will have the replacmant i will bolt ot with a torqe tool like it need to be.

 

[[email protected]]

Yes, loosen the 2 pinch bolts in the engine block and then remove the 3 bolts from the output shaft. Pay attention to these bolts. Only 1 of them has a washer under the head. It must go back in the same position.

After that, it should pull out of the engine fairly easily. Mine needed a bit of a tug.

Its NOT recommended to replace the whole unit with another because the gears are a matched set and the shims are matched to the gears. It would be best to just replace your seal. I have heard of another vmax owner replacing the whole unit without problems but it is not recommended.

 

[uri gal]

I gusse you are right.
So i am good to go
Thank u for the help, and thank other.

 

[uri gal]

just note - the parts from 85 and the later model are different!
the 85 don't have a washer on the shim pinion, and also the shim pinion is called T30 while the later models is T015 - and have different serial number
the washer and the nut on the yoke is also different

this is for the other guys that will have this issues in the future

 

[wildweasel_pt]

What you have is the left part of this assembly above. By removing the 3 M8 bolts you can just pry out the hub. No need to loosen to top 2 bolts. What holds it into place is that oring you see on the pic. Be careful not to loose the sheet metal shims between hub and case. The yoke seats on the outer tapered bearing inner racer and then the thick washer goes on top of yoke and then the lock nut. That is not a crush washer it's pretty stout and hard. The torque is very important due to set the load on both tapered bearings as noted before. As for the seal you can just pry it out with a thick flat screw driver. When installing the new one I would recommend making a driver (tube) with the same diameter so you make sure it goes in square and it doesn't twist which could ruin the seal. Before disassemble I would get a flash light and verify if there's any visible damage on the seal though black oil is surely engine oil as gear oil is yellowish. Another thing the hub face shows an arrow make sure you install it the same way otherwise the lubrication ports can be misplaced (through holes on hub side to oil the bearings - they need to be vertical)

 

[uri gal]

Thank you - it was very helpfully !

 

[uri gal]

In a second thought is not so easy to install it properly …

I read and see some videos on it on YouTube

The free play of the unit need to be precise!

To do it right – I should use a Dial Indicator Magnetic Base & Point Set – but for tuning it correctly I should use different sizes of shims till I get to the correct free play… (if I understand it right)

Did I understand it correctly?

From where I can buy a pack of shims with a different thickness ?

 

[Redbone]

For the 1985 model year they offer 2 shim sizes (see part #20):
http://www.ronayers.com/oemparts/a/yam/50042686f8700209bc78860f/middle-drive-gear

For the 2002 model year they offer 6 shim sizes (see part #20):
http://www.ronayers.com/oemparts/a/yam/50044844f8700209bc7900ea/middle-drive-gear

 

[[email protected]]

You don't need to replace any shims. It is already set from the factory. The shims set the gear lash. The shims are matched to the gear set. Changing a seal will have no effect on lash.

As noted, there is a crush collar inside the assembly. When you tighten the pinion nut, the collar collapses. It is possible to reuse this if you tighten carefully. If you make it too tight and the gear is difficult to turn, you will need to replace the collar with a new one and start over.

The crush collar is part #12 in the attachment. #18 is the oil seal you should replace. You may want to purchase #19 which is the o-ring that seals the output shaft in the block.

 

[uri gal]

The dilemma is this,

I have two options to figure it out

1. Rebuilt my 85 unit assembly – new seal, o ring, bearing…..
2. get a used unit assembly

about option 1:
from what I read in that post – Its not going to be easy to rebuilt it, and probably need to work with bearing, pressure and special tools – this is not for me

if I just could pull out the oil seal (part18) and put a new one without disassemble the unit – it could be the best solution for me.
wildweasel_ - write something about it – and I will be glad to hear more about it – it is possible ? how? With or without to open the three bolts / pull out the assembly or not) ?

about option 2
a friend from US is sending me a used unit that taken from 2004 vmax with 10k.
the problem with that option is that will need to tune the lash from the start (I will get a magnetic base dials )
from what in understand , I cannot used the formula T=A-B because this is a used part, so I will have to handle it when I will be in front of the unit while the bike will be dissemble.
For doing that I will need to have a pack of several shims with me.

**remember that the 85 models are different and not always sharing same parts – it will fit?
What about that washer inside one of the three bolts? (85 models don’t have, later models do have) .. I have an headache…..

General rules that I learned till now and need to keep:
1. lash 0.05mm – 0.12mm
2. new o ring - always
3. keep the position of the arrow
4. keep correct torque
5. start from “above” – using big shims in the start – because the unit have a cruse washer

only a week ago I thought that all of that work its only 3 bolt that need to open and close after 3 minutes … now it look to me more like missile science Lol

I need your feedback – what to do, how to do, and what an option will be better for me


Thank u my friends, I am really appreciate it!

 

[wildweasel_pt]

Dude just buy the seal, undo the Ujoint install seal and tighten everything up to the required torque settings. Don't make it more complicated than it is. You can re use the "crush" collar with no problems. Make sure that the shims go back to original position and you are golden. I would strongly recommend to use a driver to seat the oil seal as it's pretty wide around 2ish inches and it's easy to warp if you use a regular hammer around it.

 

[wildweasel_pt]

Regarding the lash there's hints on service manual but as a rule of thumb you can measure yours before disassemble and it should be within spec. If you decide to install another hub just use shins in order to achieve same lash. I'm sure you don't need any other hub assembly if yours is not damaged which I think it's not. Gears don't usually go bad and he weakest point of this assembly is the threaded stub for the yoke that sometimes breaks by shearing by the "crush" washer. I had to replace one for a friend a few years back due that failure and i just replaced the whole thing. There was no need to adjust lash as it was in the ballpark and it's been running well since. But I tend to look at things in a pragmatic way though. Don't forget lash will tighten when you torque the 3 bolts to spec so make sure you measure lash with the bolts properly torqued if you desire to do so. This will only be needed if you replace the hub assembly with the output shaft. If you keeps yours you just need to keep the same amount of shims you started with as long as lash is within spec prior disassembly.