Transmission Main shaft to Main drive gear oil Leak

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51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

Transmission Main shaft to Main drive gear oil Leak

#1

Post by 51Hog » Thu Mar 13, 2008 12:27 am

I decided to chase down a big leak today. I removed the clutch and the primary tins from the 51 fl 4 speed.
I can clearly see that there is oil leaking from between the outside of the main shaft and the inside of the main drive gear.
I have looked in the books, and just do not see any provisions for a seal in this area.
The main seal between the Main drive gear and the case is not leaking, neither is the rubber clutch rod seal on the inside of the clutch nut.
I did notice that the large nut that holds the sprocket onto the main drive gear was not tight, and the sprocket was not pulled up tight to the main drive gear spacer.
Any advice would be greatly appreciated.
Dale



Cotten
Posts: 6791
Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

#2

Post by Cotten » Thu Mar 13, 2008 1:23 pm

Dale!

Maindrive gears with seals were not introduced until '65.

Therefore, any wear upon the bushing and/or shaft will allow increased seepage. Normally, all seepage should be diverted into the primary by the 35159-39 deflector.

Naturally, over-filling or extra lean on the jiffystand will promote it as well.

Beyond a premature rebuild, commercial band-aid nuts with seals are available, BUT:
They will only work with a '65 and later clutch hub, and they quickly wear away upon the shaft due to the shaft's slop, and a lack of a counterbore within the gear for the seal's lip.

If the level in the tranny doesn't fall quickly, you may wish to only address why the deflector did not keep the mess within the primary. The loose nut may be all it was, but be certain when the inner tin is installed that the deflector is well within it.


....Cotten

51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

#3

Post by 51Hog » Thu Mar 13, 2008 5:05 pm

Thanks for the reply Cotten,
Most of the oil was going into the primary.
So much so that the clutch gets oiled-----regularly---- I have to watch while going up hill it will start slipping.
When I would stand the scooter up, the oil would run out of the nipple on the inner case.

Sure is making a mess of my back tire, frame and inside of fender.
I am thinking that I may run a piece of tubing towards the back of the bike from the nipple on the primary. Hopefully that will keep most of the oil off of the white wall and out of the fender.
Meanwhile, I will be looking to buy a main shaft and bushing for the main gear. Also this time I think I will put in the later model 1st-3rd gear set. I have a pretty good howl while in third---Still no shift problems tho.
When I rebuilt the tranny, about 4000 miles ago, the main shaft was within tolerance, so I did not replace it.

Any idea what measured quantity of 80/90 oil I should be using.
As far as over filling---I do not doubt that I have over filled.

I will look into making the old gal stand a little straighter on the stand.
She leans quite a bit. I need to watch when I fill the tanks. Fuel leaks out of the cap vent and down the side of the tank and onto the rubber foot board. The rubber doesn't like that!
Thanks for your input,
Dale

VintageTwin
Panhead Register Member
Posts: 618
Joined: Mon Aug 16, 2010 7:18 pm
Bikes: '46 Knuck. '57 Panhead, '59 Panhead
Location: Repop Hell

#4

Post by VintageTwin » Thu Mar 13, 2008 6:27 pm

Stand the bike up. Look at the oil level at the bottom of the case. If you can see it, that's enough oil (on a trans with a worn mainshaft/bushing).
Use Harley-Davidson Formula+ for all transmissions.
imo, Rebuild the transmission. Be sure you know who's doing the actual re-building. You can ask someone here to re-build it, or you can box it up fully stuffed with packing material, in an export-quality box (S&S® makes a good one!) and send it to http://stettsironhorseranch.com. He'll guarantee it. I'll guarantee the transmission, in addition to his guarantee as long as it's for a 74 cu. in. Knuckle or Pan.
Don't email him. Call them.
Your chasing a major problem that a seal won't repair. Send your tranny off for repair (tomorrow) while you work on other places around the bike. Do whatever Stett tells you to do. Send them a cleaned exterior transmission out of respect.

51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

#5

Post by 51Hog » Thu Mar 13, 2008 7:06 pm

Thanks for the reply VT,
While I probably will be sorry, I will not be shipping the tranny out for repair. The innards of this tranny are really very simple. When I rebuilt it, I brought everything back to factory new specs with the exception of the main shaft which was Just Barely within tolerance. It came back to bite me--Lesson learned.
Once I have the parts in hand, I can do the job in a weekend.
If I ship it out, the freight alone will cost more than the main shaft.
also I will be at the mercy of the repair shop ---time wise--
My riding season is pretty short here in Alaska.

VintageTwin
Panhead Register Member
Posts: 618
Joined: Mon Aug 16, 2010 7:18 pm
Bikes: '46 Knuck. '57 Panhead, '59 Panhead
Location: Repop Hell

#6

Post by VintageTwin » Thu Mar 13, 2008 8:07 pm

Good and understood.
Stett allows no more than 0.005" free-play on the counter shaft. The free-play is accumulative and by the time you get to the top, it's out of spec.
Use an Andrews mainshaft if available. Use Andrews everything if available.
EasyRider had a transmission rebuild stapled book back in the 70's. Took you through the steps one-by-one for the most part. Sunnen-hone the bushing.

51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

#7

Post by 51Hog » Thu Mar 13, 2008 9:45 pm

Thanks for the tip VT,
I will report back when I get the deed done.
I am going to order parts and ride for a little longer helping to maintain the roads with oil--LOL

fourthgear
Posts: 1365
Joined: Mon Apr 11, 2005 1:12 pm
Location: north florida

#8

Post by fourthgear » Thu Mar 13, 2008 10:41 pm

51hog
Don't be afraid to use Rev Tec parts , I have a whole set in mine and they have proved to be up to par with any other manufacturers . If you are going to pull the trans apart again to replace the main shaft , replace the main drive gear with the late model one with the seal in it , you won't regret it .Main drive gear end play is some thing else that will let oil by if not up to specs. ,0.003-0.013 , there's a thrust washer set you can get so you can set it up right( your sprocket nut being loose may cause damage to the washer/spacer, not to mention the main drive gear bearing assem.). The newer third gear set makes less noise,( better supported ), but did it do it all the time or just lately ? I ask because if there is play in your main shaft bushing in the main drive gear , it could be part of the problem , but they changed to the new gear set for a reason.

PanPal
Posts: 1083
Joined: Wed Apr 21, 2004 8:57 pm
Bikes: 50 EL custom
58 FL
76 FLH All Original
Location: Maryland

#9

Post by PanPal » Thu Mar 13, 2008 11:32 pm

I like the new main shaft and the clutch gear with the provision for the seal. The seal helps a lot. Last time I kept as many Harley part in it as I could because they are better quality steel than what you buy aftermarket. But....

I've just recovered from a grenaded transmission case. This was due to the sprocket nut coming off and the clutch gear walking so far in it went into two gears at the same time. Lesson learned. It doesn't take much to make sure the sprocket nut is tight. You don't even have to disassemble anything to check it. Always buy new locking tabs when rebuilding.

I had a clunk shifting into 2nd and a Howl in 3rd prior to the work. I now believe many noises come from replacing only the gear that looks bad rather than replacing the set. They seem to mesh better all new. I went with Andrews and stayed with the early ratio because it felt right and changing the ratio changed 1st and 3rd. I think the change for 3rd would help, but I like the way first gear is now. I may be wrong, but it sounds and feel good now. I do need to adjust my chain oiler now because It had been lubricating the primary chain with the oil that was leaking from the main shaft bushing. That little seal is working pretty well now and I'm running 60W instead of the heavy gear oil. So far so good!

51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

#10

Post by 51Hog » Fri Mar 14, 2008 1:38 am

Third gear has whined from the day I put it in the tranny.
I just tightened everything back down and the end play on the main gear is just within spec. I am going to put a few more miles on it to see what happens.
My tires do not like the ice on the roads---Not even a little bit!!!!
Seems like whenever the Ice burns off of the roads, It snows again.
When I rebuilt the tranny, I used all harley parts-- Some NOS, and some just good Old Parts.
Anyone have a part number for a newer style shaft that will work with my setup? What all do I need to get to make the new shaft work?
Thanks

fourthgear
Posts: 1365
Joined: Mon Apr 11, 2005 1:12 pm
Location: north florida

#11

Post by fourthgear » Fri Mar 14, 2008 1:12 pm

There are several ways to repair a worn main shaft bushing, it all depends on what shape the main shaft is in, you can just replace the bushing and have it line honed to the main shaft specs.( just getting the bushing out of the main drive gear can some times be a problem , they can be cut out ,but very carefully) . Hows the taper for the clutch hub? Key way for clutch hub key , any chips in it ? How old is it, any discoloration any where the gears ride on ? That main shaft seal is in the main drive gear , the 65 -76 ( 77 went to a one piece bearing )gear will get the main drive gear with it. If both your main shaft and main drive gear are in question , replace them both. Always use new seals and locking tab washers and any of the retaining rings that hold the various components in place in the tranny.

http://www.hydra-glide.com/coppermine/d ... ?pos=-1210

I always question the validity of components that say they are NOS unless they come in HD wrapping and even then I wounder . There is no way they made an endless supply of the oem parts , even if from over seas , in which I would not trust any way. As far as gear sets or components from swap meats , well your on your own there .my two.

PanPal
Posts: 1083
Joined: Wed Apr 21, 2004 8:57 pm
Bikes: 50 EL custom
58 FL
76 FLH All Original
Location: Maryland

#12

Post by PanPal » Fri Mar 14, 2008 5:55 pm

What I am calling the clutch gear is what you are calling the main drive gear for clarification. Also check for wear on the main shaft where the bushing runs. This makes fitting a bushing tuff. The bushing must pass over a larger diameter on the shaft before reaching it's running position.

Fourthgear,
Does you Rev Tec set have the small seal in the end of your main drive gear? Not sure about your application, is this for your 65 Regardless the sealed gear can be used in earlier case. But I'm not sure If it can be used with the original shaft or not.

fourthgear
Posts: 1365
Joined: Mon Apr 11, 2005 1:12 pm
Location: north florida

#13

Post by fourthgear » Fri Mar 14, 2008 8:14 pm

The Rev Tec gear set in the photo is in the 54 tranny in my older Pan ,and Yep, it has the seal at the end of the main drive gear , kit is 2.60 to 1 . Had every thing needed except thrust washers for the main drive gear and counter shaft. I had to order the trust washer set for the main drive gear & counter shaft, its nice to have the whole range of sizes to make sure end play is proper.
I'm not sure if all after market main drive gears are all the same ,unless you get a OEM,NOS, type main drive gear , it will probably have the recess for the seal.The four speed main drive gears are all 26 teeth and as long as you get one made for a 65 -76 it should be a sealed main drive gear for the main shaft.The books show 38-77 (loose rollers )and 77-84( needle bearing) for the different main drive gears and the shafts are all the same except for the different lengths for certain years ( electric starts , 65-69, & 70-84 )so pretty much any main drive gear will work , Just the main shafts have diff. lengths.

Cotten
Posts: 6791
Joined: Mon Aug 26, 2002 9:09 am
Location: Central Illinois

#14

Post by Cotten » Sat Mar 15, 2008 3:07 am

Beware that R&Ring a maindrive gear bushing isn't as simple as it sounds.

The Factory supplied Dealerships with oversized bushings (still Clevites) only because they wouldn't trust field repairs.

Take comfort in that at least they are more forgiving than Indian's, whose gear must invariably lathe-bored for acceptible concentricity.

After installing the bushing within the maindrive gear, it should be torqued upon a spacer and sprocket before reaming and honing. The stress of the assembly splays the mouth of the gear outward. If the bushing is fit without preload, it will be loose at that end upon final assembly.

That end is where the oil-retaining slinger grooves do their job.

...Cotten
PS: My first choice for internal hardware would be Eastern Mcy Parts.

51Hog
Posts: 655
Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

#15

Post by 51Hog » Sat Mar 15, 2008 5:22 am

Thanks to all for the advice and tips. After dodging the ice on the roads for about 100 miles today, and temps between 15 and 38 degrees, The rear whitewall only had a couple black splatters on it. Maybe the oil was too cold to leak--LOL
I drained the oil out of the tranny and refilled to about 1/4 inch Below the bottom of the threads in the filler hole. Tranny was not noisy, and did not get warm.
The only other thing I did was to re-torque the output sprocket nut.
I also put a 4" piece of wood under the jiffy stand which stands the bike up at about 2-3 degrees out of plumb.
I have to do this anyway with a full tank of gas, or it will leak out of the left cap vent.
You guys/gals are great!

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