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Discussion Starter · #1 ·
Hello folks,
Here is and issue that needs help.
A close friend has a 96 dyna.
There is a problem that has developed recently.
Primary oil is being sucked into the crankcase.

Crank seal has been replaced twice, by a good mechanic.
With close inspection, we believe there is a crack at the base of the stator mount, on the crankcase.
it's really hard to see it. During inspection with a light and a scribe, you can feel that there are points all around that are not smooth, and have a fractured feel.

(I'm not a bike mechanic, so it could just be rough machining)
WIth that said here are some questions


1. has anyone experinced the issue?
2. Is it possible that the crank bearing or it's race have gone bad?

Any and all input is welcome. My friend is totally bummed.
got a kid going to college and now his hog is doing bad things.


Thanks
Trix
 

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Trixboomer said:
Hello folks,
Here is and issue that needs help.
A close friend has a 96 dyna.
There is a problem that has developed recently.
Primary oil is being sucked into the crankcase.

Crank seal has been replaced twice, by a good mechanic.
With close inspection, we believe there is a crack at the base of the stator mount, on the crankcase.
it's really hard to see it. During inspection with a light and a scribe, you can feel that there are points all around that are not smooth, and have a fractured feel.

(I'm not a bike mechanic, so it could just be rough machining)
WIth that said here are some questions


1. has anyone experinced the issue?
2. Is it possible that the crank bearing or it's race have gone bad?

Any and all input is welcome. My friend is totally bummed.
got a kid going to college and now his hog is doing bad things.


Thanks
Trix
Find someone with a dye penetrant inspection kit and you can use it to see if it's really a crack. The kits are not expensive and you can find them online, but most machine shops should be able to check it for you. What does the factory service manual say about it?

I can't say that I've ever seen that problem before. I would think that it wouldn't be possible since the crankcase has more static air pressure (breather) in it than the primary, so the oil from the crankcase would be going into the primary rather than the other way around, but I could be wrong.
 

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By you saying that the primary fluid is being sucked into he crankcase, are you saying this because you notice the oil level in the tank increasing? Second, the starter bolts to the inner primary not the crankcase, although the inner primary does bolt to the crankcase, just not the same location. The biggest leak I find in the stater/primary area is the starter shaft seal where the starter shaft runs thru the primary and seals the primary fluid in.
 

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Discussion Starter · #6 ·
sucking oil from the primary

yes, folks it is leaving the Primary and getting into the crank.

Straingest thing I've ever seen.

I will check into the die.

What bothers me is that, any crack in the case should be visible.

and we are almost sure that the vacuume is coming from the crank.

:hmmm:
 

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Trixboomer said:
yes, folks it is leaving the Primary and getting into the crank.

Straingest thing I've ever seen.

I will check into the die.

What bothers me is that, any crack in the case should be visible.

and we are almost sure that the vacuume is coming from the crank.

:hmmm:
It may only be open enough to be visible when the engine is hot. That's hard to check since it will cool down pretty quick once you pull the primary cover.

I've seen this happen a few times on jet engines. An engine would use several quarts of oil during flight, leaking it all over inside the cowling. But after we refueled it and fired it up on the ground with the cowling open, the engine had cooled down and we couldn't find the source of the leak. It was only after running at high power for several minutes with the cowling closed that we noticed the oil leaking out of the cowling drain holes. Twice it was a cracked oil tank on an F101 engine (B-1B bomber). That thing drove us nuts for 4 days straight, losing about 5 quarts during a 4 hour sortie. We couldn't even see the crack when it was hot.... we only saw an oil film forming on the tank surface. We finally located the crack by performing a dye penetrant inspection.
 

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have seen it move both ways pu a coulpe of washers on the mainshaft install the extension shaft & nut tighten down plug the head breathers take the case to oil tank line aplie 15 psi on air and sprits area you beleive the crack is with windex 409 ect or use soapy water if its cracked it will bubble up
 

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A possibility is, if it has a plastic breather gear and the gear broke causing breathing problems.
The old 65 pan has no seal on the crankshaft, a little oil will enter the primary, but the engine wont draw it out.
 

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I just remembered something else....

It may very well be a crack. Dyna's are known to have trouble with cracks in the engine crankcase and inner primary case. This is due to their design since the swingarm bolts directly to the transmission rather than the frame. Because of this, almost all of the torque is applied to the left side of the engine/tranny unit which is only joined together by the inner primary cover. There is nothing holding the right side together except the engine and tranny mounts at the frame. When accelerating hard, doing burnouts, or after increasing torque with modifications to the engine, this increases side-to-side flexing which will cause cracks to form in the cases. On a stock bike, it's not a problem.

This is why Tony Carlini came up with the "Torque Arm", which was later copied by the MoCo which sells it as the SE "Race Brace". This bolts to the right side of the engine, between the crankcase and tranny and strengthens the entire drivetrain. I bought one on ebay last year, copied the dimensions, then made my own from 6061 aluminum. (then sold the original for a nice $125 profit... LOL!)

I made mine as a two-piece assembly, though. That way I don't have to pull the whole thing if I have to remove the cam or trans cover. The torque arm is a MUST HAVE item for those who have hi-torque Dynas! Another thing I noticed after installing it was that the bike handles a LOT better on the twisties. Probably because the front and rear wheels are more likely to stay aligned with the arm installed. There's a very noticable difference!
 

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Here's a post I made a few months back..hope it helps..

2001 FLTRI...I hope this finds you before you spend a lot of money...I had the same problem on my '90 dresser..the cure is to take the primary apart..take the stator off ...clean the area with brake cleaner...clean it again...now for the next 3 days you put a bead of Loctite 290 (about $13.00 for a 2 oz bottle, buy it at a heavy machine shop) all around the steel sleave on the crank bearing...it's hard to see but if you look real close you'll see a difference in the metal...do it once a day...then when you are putting things back together you'll have 2 screws that hold the wires for the stator..put Loctite Blue on those screws...I did mine in '97 and it's still working....the part that bites my butt is that I told the dealer I was losing a half qt. every 1k ...guess what..that's normal ...then he comences to tell me not to put more then a qt of oil in the primary cause these "new" machines don't need anymore then that...I found out in '97 that they had a TSB on the problem since Feb of '90....just more of HD BS....good luck
 

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SKUNKY said:
Here's a post I made a few months back..hope it helps..

2001 FLTRI...I hope this finds you before you spend a lot of money...I had the same problem on my '90 dresser..the cure is to take the primary apart..take the stator off ...clean the area with brake cleaner...clean it again...now for the next 3 days you put a bead of Loctite 290 (about $13.00 for a 2 oz bottle, buy it at a heavy machine shop) all around the steel sleave on the crank bearing...it's hard to see but if you look real close you'll see a difference in the metal...do it once a day...then when you are putting things back together you'll have 2 screws that hold the wires for the stator..put Loctite Blue on those screws...I did mine in '97 and it's still working....the part that bites my butt is that I told the dealer I was losing a half qt. every 1k ...guess what..that's normal ...then he comences to tell me not to put more then a qt of oil in the primary cause these "new" machines don't need anymore then that...I found out in '97 that they had a TSB on the problem since Feb of '90....just more of HD BS....good luck
Sounds like a good idea, if the cases are not cracked. Hopefully they aren't. I'll have to print this and put it in my maintenance binder. :cheers:
 

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Discussion Starter · #14 ·
Sucking oil

Skunky!
THat a great idea.
sounds like loose tolerances in the bearing and sleeving.
I'll for sure try that.

I'll keep you posted on the progress.

Thanks a million guys.

:beer:
 

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My Indy told me about that fix after I discovered what the problem was..He showed me the TSB from Harley dated Feb. 1990..I bought my bike in April 1990..no recall cause it wasen't a safety factor...but I thought that HD had corrected that problem by '92 or '93..oh well..it's those little things that give HD it's character..thanks for the beer..
 

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There is a service bulletin at the dealer pertaining to that problem. It was prevalent in the '89-'90 models, the insert that was cast into the cases on the sprocket (primary) side would loosen and allow oil to be swapped. Some would move the engine oil to the primary. I have not seen the problems in any engines out of those years but it doesn't mean that it's not happening to the '96 you have seen. The bulletin has a way to check for this and I would suggest getting a copy and test.
 

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"Skunky
did you apply the loctite with the seal in place?"


Yes I did..the Loctite 290 sucks itself into the crack..(I:E gap )
 

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Yes, there was a problem on some years of the cast into the aluminum main bearing mount. And that piece could work considerably loose. The oil problem was oil swamping the primary, and vibration.
the problem here appears to be the opposite, where oil is being sucked out of the primary and into the regular oil system.
Now whats really weird about that is the primary oil should be lower than the main bearing. and also it doesnt happen on 65 to 68 engines that have no main seal and that have had the primary converted to non circulating.
A way of testing if the bearing insert has loosened in the left case is remove the complete alternator and grab the inserts protruding nose with a pair of channelock pliers and twist it around various directions. If it is loose you can see oil squeeze out between the insert and the aluminum case.
 

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Discussion Starter · #20 ·
Thanks to all

Folks,
I want to Thank all who posted and gave their input.
This site is a godsend. I can't even begin to express my appreciation for the information that has been passed on here.

Now,
My buddy had the bike fixed!

No cracked cases.
The bearing seal was replaced and a spacer was replaced as well with liberal amounts of sealant.

From what i've been told the original spacer had some scoring.
I'm not a mechanic, but this is the information i was given.
Maybe the original "good mechanic" didn't install the seal properly. (twice no doubt) But this cannot be confirmed.
It could be the most logical step.

I did look at the cases and there was a possible area that could have passed for a crack, but not really fractured so you could really say it was cracked. (Good learning expreience for me)

A road trip to Phoenix and back confirmed the problem has been cured.
I will try to get my friend to post on this thread and lay out the straight scoop.

Once again I am sincerly thankful for the good folks on this site, and the useful insight that has spread here.
Thanks:clap: :clap: :clap:


Trix
 
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