Jockey Journal Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
72 Posts
Discussion Starter #1
So I decided it was time to tear the primary off my Shovelhead and fix the transmission leak. It only leaked when running on the kick stand and as I suspected turned out to be the small seal and the end of fourth gear.
I installed two new seals and a super nut this time. As I did a test with my hand drill rotating the main shaft I noticed the chain wheel is wobbling. Maybe it's just me but it seems excessive. Is it normal (that's AMF Harley for you?) or is something wrong? I have a video of it here: Video of wobbling chain wheel
63898340941__86422537-4092-4AEF-B505-40E2DD44FCBF.jpeg
 

·
Registered
Joined
·
1,296 Posts
In the shop when we see the small seal leaking - every thing from that spot forward is a bandage if the HI gear bushing is not replaced - and most times the area under the hi gear bushing ON the mainshaft is worn down .001 to .002 thousands - the wear plus the original .001 to .0015 clearance is too great for that small seal to hold back the volume of oil against it on the stand

it will not stop until the trans is completely gone through and put back into spec - could what you are attempting work for a while sure
 
  • Like
Reactions: 70FLH

·
Registered
Joined
·
72 Posts
Discussion Starter #3
In the shop when we see the small seal leaking - every thing from that spot forward is a bandage if the HI gear bushing is not replaced - and most times the area under the hi gear bushing ON the mainshaft is worn down .001 to .002 thousands - the wear plus the original .001 to .0015 clearance is too great for that small seal to hold back the volume of oil against it on the stand

it will not stop until the trans is completely gone through and put back into spec - could what you are attempting work for a while sure
Thank you for the reply. The fourth gear bushing was replaced and honed to fit the new mainshaft less than 2.000 miles ago and new rollers for the fourth gear were installed. I put in a spacer modified with a groove to have an o-ring seal (Saddlebagrail fix) maybe that spacer has collapsed from over tightening? I shot this video of the leak prior to the fix where the fourth gear doesn't seem to wobble: Video of transmission leak
 

·
Registered
Joined
·
1,296 Posts
What oil did you use the GL5 gear oil will destroy the trans brass is that time frame

years back we went back to motor oil in gear boxes

grab on to 3 and 9 o’clock on the trans drive gear NO chain on it - and see if it rocks - if yes - its shimmed incorrect and or the bushing is wiped out
 

·
Registered
Joined
·
72 Posts
Discussion Starter #5
I tried rocking it at 3 and 9 o'clock. It is firm with no hint of play. I removed the super nut and still it is a tight fit on the shaft. The bushing must be in good shape.
I use Red Line 80W Motorcycle Gear Oil with ShockProof - The green stuff which is excellent when tracing leaks . It is synthetic but supposed to be safe for yellow metals, but I can't find any exact info or GL rating on their website.
 

·
Registered
Joined
·
1,296 Posts
The super nut your using they had 2 different ones i have seen over the years - one is flat against the locking tab - the other uses a small o ring between the nut and the lock tab < not a fan we cut the groove off and use it as a flat nut with out using the o ring

Now you said the gear is not running true - if it does not move back and forth up and down it not going to move – have you isolated the movement - i know you posted a film but my computer stuff is a American motors rambler with a flat head 6 cylinder - so i cant down load it
 

·
Registered
Joined
·
407 Posts
I watched your video.

It looks as the seal in that nut is running eccentric.

If I was to guess, I would say the bushing is either worn or was machined offset.

To test, mount an indicator to the trans case with the indicator pointer on the main shaft. Trans in neutral, hold the main shaft from spinning and then spin the sprocket. If the shaft moves up and down, the main drive gear bushing is running eccentric.

Past that, I have never had any luck with those super nuts.
 

·
Registered
Joined
·
72 Posts
Discussion Starter #8
If I was to guess, I would say the bushing is either worn or was machined offset.
Exactly what I start to suspect - the offset machined part - but wouldn't that result in some very worn parts by this point? Everything feels tight.
My mind starts coming up with far fetched theories like the thread on the fourth gear itself being machined slightly off by the Monday morning shift at the AMF machine shop.

Past that, I have never had any luck with those super nuts.
I only installed the super nut (it has an o-ring on the back, johnjzjz) as a last line of defense if the two small seals both fail (fingers crossed they hold up this time) to prolong the time before I have to tear down again. I will run it as is and if it starts to leak out goes the tranny.

In regards to GL-5 oils and yellow metals, I found this link where he does some actual testing:
 

·
Registered
Joined
·
72 Posts
Discussion Starter #9
On a side note I just looked at the old seal - the one that leaked. It has a very fine tear which I suspect is from the installation where someone (not me, I swear 😇) omitted to put tape over the razor sharp key-way edges on the shaft.
 

·
Registered
Joined
·
1,296 Posts
Grease the seal rubber install the slinger then install the pair together deep below the trans edge as the cog stay if it has one will rip the seal if its out to far - the seal should have a backing making it a 2 lip and no cork going in with it
 

·
Registered
Joined
·
1,742 Posts
Thanks for that gear oil/yellow metals link, 70FLH. I saved it for leisurely perusal.
 

·
Registered
Joined
·
1,686 Posts
I'm baffled how if it's all in clearance and it's still leaking. I had this issue but that was due to a wear groove where you now have a seal. I've had great luck with the super nut, and using extremely thick driveshaft oil designed for early 1900 bentleys!

As for the wobble.. peculiar!! interested to follow and find out what's causing it. I think Dan could be on the money.
 

·
Registered
Joined
·
1,296 Posts
The turn of the century bentleys used whale oil that was blended with something i forget what - in the states i was a RR tech both for the motor company but also my own shop and have worked on those 1970s in NYC
image.jpg
 
  • Like
Reactions: 70FLH

·
Registered
Joined
·
1,686 Posts
Had to spoon it in almost!

But, it's done the trick for me, my lil old 40 tranny works like new!
 
1 - 15 of 15 Posts
Top