Fluid Change

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Oct 17, 2012 | 12:45 PM

gr8jeep

Thread Starter

Stage II

Joined: Oct 2012

Posts: 2

Likes: 0

From: New York

Fluid Change

Hello , first post here , new Harley Owner also , recently purchased a 74 Sporster and was getting ready to change out all the oils . I watched the how to video on the primary checking the chain tension and adding the quart of oil but i guess i still don't get it . On my Sportster the plug on the underside was leaking so i pulled the plug and dumped the oil , the stuff was pretty black . Where does this get refilled ? I was under the impression the Primary and Tranny used the same oil , i was only given a quart at the Harley place i bought my stuff from and more then a quart has come out at least it seems like its more so i figured i better join up and ask the question before i screw something up ......the reason i pulled that plug was because it was leaking and i had also gotten a new drain plug washer ..... any help would be much appreciated , Thanks

Oct 17, 2012 | 04:16 PM

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

You need both of these ...

99484-78 Factory Service Manual
99451-78B Factory Parts Catalog

Widely available from local bike shop, HD dealer, eBay, internet sellers, amazon, J&P Cycles, etc. Put the part numbers into the Google and eBay searches.

The primary takes 1.5 pints == 24 fl oz; it does not take a whole quart. Add it in thru the primary chain inspection port [the opening above the shift lever; the other further back is the clutch adjustment port]. With the bike level add it until it starts to drip from the oil level bolt hole ...

Oct 17, 2012 | 06:00 PM

gr8jeep

Thread Starter

Stage II

Joined: Oct 2012

Posts: 2

Likes: 0

From: New York

Thanks , i have the manual , i think what scared me was the amount of oil that came out when i pulled the drain plug on the bottom , it was well over a quart possibly close to 2 so i am guessing the guy i got the Bike from had no clue about where the oil level shoulda been , that would explain the oil running out of the inspection cover . WOW is all i can say ......

Oct 17, 2012 | 07:23 PM

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

There is an oil transfer port inside the engine. I do not know all of the details but it is misnamed and has to do with engine ventilation. When it is worn oil can pass thru and may cause overfill of the primary.

Like i say i do not really know much about this it is just something you should check into. Here are a couple of links ...

Oil Transfer/Crankcase Breather Valve
http://xlforum.net/vbportal/forums/s...d.php?t=581947

oil leaking into primary
http://xlforum.net/vbportal/forums/s...d.php?t=150130

And on a similar sounding but different topic ...

Engine breather 101 / Crankcase Vent 101
http://xlforum.net/vbportal/forums/s...32#post1960632

Oct 17, 2012 | 09:19 PM

scottfisher

Road Captain

Joined: Oct 2010

Posts: 566

Likes: 3

From: rural ontario

welcome to the forum

I have a gr8Jeep too. 96 cherokee...damn thing won't die so I can get a new one.

s

Oct 17, 2012 | 09:42 PM

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

My Cherokee is a red 1999. Here it is on Google street view. Too bad my IronHead was not out there when they went by ...

https://maps.google.com/maps?q=39+Du...86.86,,0,16.32

Oct 18, 2012 | 02:05 PM

piniongear

Stellar HDF Member

Joined: Feb 2006

Posts: 3,035

Likes: 17

From: Houston Texas

Quote:

Originally Posted by gr8jeep

Since you have a 1974 model and are new to Sportsters, I offer these comments.........

As Mick said, it takes 24 oz of oil for the primary and transmission.
Both share the same oil.

The oil you use in the primary and transmission should be the exact same oil you use in the engine.
That oil is straight 60w which you can get from a Harley dealer.

The reason you use the same oil is because of the 1974 model having a transfer valve.
This 'valve' is a one way affair that lets engine oil into the primary in very small amounts under normal conditions.
And I mean a very small amount.
The pistons coming down are what cause some pressure in the lower end, and while there is a breather to relieve this pressure, some puffs into the primary.

So why did you have so much oil inside your primary/trans when you drained it?
The answer is because your bike had sat without being started for some length of time.

What happens is the oil pump contains a ball check valve using a spring against a small bearing (ball) to keep oil from draining out of the oil tank into the lower end of the engine when the bike is not running.

You start the engine and the oil pressure from the oil pump is more powerful than the small spring and so it lifts the ball off it's seat allowing oil to be pumped through the engine. This works fine when it works, but it does not always work as intended.

So what happens is the bike sits for a week or two, maybe longer, and the ball does not do a good job of sealing.
Oil from the tank drains into the lower end.

The bike is sitting parked on it's side stand (leaning left) and if the oil reaches a high enough level it reaches the transfer valve.
The transfer valve is in the left crankcase between the primary area and the engine bottom end.
Oil then flows into the primary/transmission.
The transfer valve is a one way affair so oil comes in but does not go back toward the bottom end of the engine.

You look in the oil tank and it is a quart or more low.
What has happened is this quart or more has drained into the bottom end and most of it is also in the primary/transmission.

What can fix this 'problem'?
Just crank the engine up at least every two weeks. A brand new Sportster would load up the base sitting on the showroom floor in 1974 and we had to crank each machine up every 1 to 2 weeks to keep the oil from loading up the base.

So you did the correct thing in draining the oil.......AS LONG AS IT WAS THE TRANSMISSION DRAIN PLUG THAT YOU REMOVED.

On a 1974 you may find another plug forward of the oil pump that looks like a drain plug, BUT IT IS NOT!
DO NOT ever remove this plug for any reason.
The plug is right below the flywheel assembly and the crankcase is about a scant 3/8 inches thick at this point and the aluminum is crumbly and of poor quality.
When you remove this plug you will never get it back in.
If you are lucky it will go back in and only leak oil from now on.
Most likely the threads in the crankcase will strip out and then you have serious trouble.
Serious trouble like you are going to have to take the entire engine apart and split the cases to fix this blunder.

You cannot re-tap the hole or install a Heli-Coil because there is only 3/8 inch between the flywheel and the inside of the crankcase.
My knowledge of this plug is that the factory had a hole there for some machining purpose and rather than welding up the hole they ran a one time plug in there to seal it.

I understand a plug is cheaper than a weld, but this plug is not mentioned in any service manual that I have ever seen and to take it out is a serious matter.
A lot of guys here on the forum have made that mistake thinking it was a drain plug.

The transmission drain plug will have a 5/8 inch head and is located at the rear of the engine underside.
I sure hope that was the plug you removed.