March 28, 2024, 08:25:26 AM

News:


M8 trans fluid leaking in primary

Started by grnrock, February 17, 2017, 02:31:46 PM

Previous topic - Next topic

0 Members and 5 Guests are viewing this topic.

Jobie

Then why does venting the primary work?  Because the tranny needs more venting to relieve more pressure.  That goes back to what I was saying before.......... Hd went from a 3/16 to a 1/8 vent in the top cover.  Just like water in a hoes, want more water get a bigger hose.  In this case, size does matter.

HogMike

Quote from: Jobie on June 23, 2019, 02:59:23 PM
Then why does venting the primary work?  Because the tranny needs more venting to relieve more pressure.  That goes back to what I was saying before.......... Hd went from a 3/16 to a 1/8 vent in the top cover.  Just like water in a hoes, want more water get a bigger hose.  In this case, size does matter.

Harley transmissions have had a vent since 1926 IIRC. The trans vent is to keep the inside at atmospheric pressure regardless of heat, altitude, etc.
there should be no positive pressure in the trans case, unless the vent is clogged, not likely.
The primary case will go into a negative pressure during some running conditions. Some are looking at the causes to be engine sprocket shaft seal allowing crankcase negative pressure to impact the primary case through the lip seal.
One fix a factory tech tried is a different seal and a double seal. Didn't really fix the issue but slowed it down a bit.
Cheapest and easiest fix was to relieve the NEGATIVE pressure in the primary case.
Harley doesn't have to do a massive recall (non safety related) AND they get to profit buy selling a rubber hose and directions to their loyal customers.
Win win for Harley.
Dad always said "follow the money"!
JMHO
:potstir:
HOGMIKE
SoCal

PoorUB

Quote from: Jobie on June 23, 2019, 02:59:23 PM
Then why does venting the primary work?  Because the tranny needs more venting to relieve more pressure.  That goes back to what I was saying before.......... Hd went from a 3/16 to a 1/8 vent in the top cover.  Just like water in a hoes, want more water get a bigger hose.  In this case, size does matter.

If the transmission was building pressure, venting the primary should make it worse! Trust me, any sized vent on the tranny is enough. The tranny building pressure is just short of ridiculous. The gradual increase in heat and then pressure in the tranny is slow and minuscule.

Some speculate the engine is pulling air through the crankcase seal, causing a vacuum in the primary, pulling oil from the tranny. Makes sense if the primary vent works. Funny it does not pull primary lube into the engine.
I am an adult?? When did that happen, and how do I make it stop?!

HogMike

Quote from: PoorUB on June 23, 2019, 05:48:34 PM
Quote from: Jobie on June 23, 2019, 02:59:23 PM
Then why does venting the primary work?  Because the tranny needs more venting to relieve more pressure.  That goes back to what I was saying before.......... Hd went from a 3/16 to a 1/8 vent in the top cover.  Just like water in a hoes, want more water get a bigger hose.  In this case, size does matter.



If the transmission was building pressure, venting the primary should make it worse! Trust me, any sized vent on the tranny is enough. The tranny building pressure is just short of ridiculous. The gradual increase in heat and then pressure in the tranny is slow and minuscule.

Some speculate the engine is pulling air through the crankcase seal, causing a vacuum in the primary, pulling oil from the tranny. Makes sense if the primary vent works. Funny it does not pull primary lube into the engine.

One theory is the alternator "flings" whatever oil happens to make up far enough to the seal. Mostly air/vapor at that point.
:nix:
HOGMIKE
SoCal

JMHD

Quote from: PoorUB on June 23, 2019, 05:48:34 PM
Quote from: Jobie on June 23, 2019, 02:59:23 PM
Then why does venting the primary work?  Because the tranny needs more venting to relieve more pressure.  That goes back to what I was saying before.......... Hd went from a 3/16 to a 1/8 vent in the top cover.  Just like water in a hoes, want more water get a bigger hose.  In this case, size does matter.

If the transmission was building pressure, venting the primary should make it worse! Trust me, any sized vent on the tranny is enough. The tranny building pressure is just short of ridiculous. The gradual increase in heat and then pressure in the tranny is slow and minuscule.

Some speculate the engine is pulling air through the crankcase seal, causing a vacuum in the primary, pulling oil from the tranny. Makes sense if the primary vent works. Funny it does not pull primary lube into the engine.
I wonder if the theory of the engine pulling air through the seal causing the transfer is directly related to the sumping problem? Sure seems like this engine is having difficulty breathing and is fairly choked up by the extremely small breather assemblies. Just a thought.  :scratch: :nix:

PoorUB

Quote from: JMHD on June 23, 2019, 07:06:50 PM
I wonder if the theory of the engine pulling air through the seal causing the transfer is directly related to the sumping problem? Sure seems like this engine is having difficulty breathing and is fairly choked up by the extremely small breather assemblies. Just a thought.  :scratch: :nix:

Too small breathers would add to crankcase pressure, which also would likely stop any air being drawn from the primary. All engines have some blow by the rings, the crankcase vents are there to relive it.
I am an adult?? When did that happen, and how do I make it stop?!

Jobie

Two small breathers would not add to crankcase pressure.  FYI........ Vents relieve pressure not build it.  What goes on in the tranny and primary has nothing to do with the venting or pressure in the crankcase.  Crankcase pressure is caused by SUCK/SQUEEZE/BANG/BLOW... Google it.

PoorUB

TOO small, not TWO small.

Jobie, I have been rebuilding engines for 50 years. I know what a crankcase breather does. I am not certain some others here do.

Re-read my posts.

I am an adult?? When did that happen, and how do I make it stop?!

HogMike

All of this goes back to the original question of WHY the primary case goes into a negative pressure while running. I'm pretty sure it has nothing to do with the transmission building "too much pressure" .
In theory, the gearbox vent will also vent the primary.
Think that when the primary goes into a negative pressure, whatever oil is pooled in the pushrod cavity will get pulled into the primary.
Thus the idea that the primary is influenced by the "suck" part of the 4 stroke process. How else would you explain how the negative pressure happens?
:slap:
HOGMIKE
SoCal

Jaycee1964

New, new update was done to my bike yesterday.  Primary vent installed and trans side seal.  Will be reporting back.  I typically ride 70 miles per day M/F so it should rear its head pretty quick.

One note though... For some reason, it shifts more quietly :scratch: on both up and downshift.  Maybe it's me...  Dunno.  But I did notice that when its cold the primary is relatively quiet but when warmed up if I blip the throttle slightly I hear a primary rattle now... :scratch:
If you have to stop and think about if it is right or wrong, Assume it is wrong.

cbumdumb

Quote from: Jaycee1964 on June 27, 2019, 05:23:32 AM
New, new update was done to my bike yesterday.  Primary vent installed and trans side seal.  Will be reporting back.  I typically ride 70 miles per day M/F so it should rear its head pretty quick.

One note though... For some reason, it shifts more quietly :scratch: on both up and downshift.  Maybe it's me...  Dunno.  But I did notice that when its cold the primary is relatively quiet but when warmed up if I blip the throttle slightly I hear a primary rattle now... :scratch:

My rgu up shifts almost silently now with breather tube installed in primary....almost a thousand miles so for and no change in oil levels or shift feel .

road-dawgs1

Quote from: Jaycee1964 on June 27, 2019, 05:23:32 AM
  Primary vent installed and trans side seal. 

Do you mean vent installed and trans oil deflector removed? Or something else
'24 FLTRX Sharkskin blue

Sunny Jim

Quote from: Jaycee1964 on June 27, 2019, 05:23:32 AM
New, new update was done to my bike yesterday.  Primary vent installed and trans side seal.  Will be reporting back.  I typically ride 70 miles per day M/F so it should rear its head pretty quick.

One note though... For some reason, it shifts more quietly :scratch: on both up and downshift.  Maybe it's me...  Dunno.  But I did notice that when its cold the primary is relatively quiet but when warmed up if I blip the throttle slightly I hear a primary rattle now... :scratch:


Primary cover has been off. You probably have new oil and perhaps the tensioner was adjusted. Seems reasonable.

HDDOC

I use Redline in my 2019 Tri and have no issues.
2019 Tri Glide

Jaycee1964

Quote from: road-dawgs1 on June 27, 2019, 02:22:30 PM
Quote from: Jaycee1964 on June 27, 2019, 05:23:32 AM
  Primary vent installed and trans side seal. 

Do you mean vent installed and trans oil deflector removed? Or something else

I see a new Vent installed in the back top edge of the primary.  Oil deflector removed and updated seal installed in the Trans.
If you have to stop and think about if it is right or wrong, Assume it is wrong.

Jaycee1964

Quote from: Sunny Jim on June 27, 2019, 04:01:31 PM
Quote from: Jaycee1964 on June 27, 2019, 05:23:32 AM
New, new update was done to my bike yesterday.  Primary vent installed and trans side seal.  Will be reporting back.  I typically ride 70 miles per day M/F so it should rear its head pretty quick.

One note though... For some reason, it shifts more quietly :scratch: on both up and downshift.  Maybe it's me...  Dunno.  But I did notice that when its cold the primary is relatively quiet but when warmed up if I blip the throttle slightly I hear a primary rattle now... :scratch:


Primary cover has been off. You probably have new oil and perhaps the tensioner was adjusted. Seems reasonable.

Dunno..  :scratch:  I brought it back to them on Saturday and the noise int he primary when hot is "Normal" Compensator noise when I lightly blip the throttle..  LOL  Hey,  They own the bike for 18 more months of warany and I already have about 11,500 miles on it in 6 months.  I figure something else is going to fail on it with the amount I ride and it'll surely be back.. 
If you have to stop and think about if it is right or wrong, Assume it is wrong.

Xyzzy

If you are on a trip, nowhere near a lift and tools, and your M8 starts to transfer oil, will adding oil to the transmission as needed be okay?

Or will it continue to go into the primary and fill that up and possibly leak into the engine area?

My guess is it will stabilize at some point, maybe half full? The shifting would be a bit rough but at least you could complete the trip.

Or am I missing something?

I don't mind checking the transmission every night.

Coyote

I'm sure it will stop transferring once the primary gets full.  :oops:

Xyzzy

Would it literally fill up entirely?

Or just to the point that the primary and transmission are at the same level?

Could the oil migrate then to the cam chest?

Coyote

How could the oil migrate to the CAM chest?    :doh:

I doubt you'll fill the primary if you keep adding transmission oil but I doubt the clutch is gonna like being half buried in it. Why not find out if you are having this issue before heading out on a long trip?

Xyzzy

I was just thinking of what to do if the unexpected happens.

:smilep:

Hossamania

Quote from: Xyzzy on July 10, 2019, 04:36:26 PM
I was just thinking of what to do if the unexpected happens.

:smilep:

You drain the primary, you fill the transmission, and you get pissed off that you can't take a small trip without carrying a few quarts of different types of oil and having to work on your bike every night. Don't forget your tools.
If the government gives you everything you want,
it can take away everything you have.

rigidthumper

Maybe they'll go to unit construction, like the Sportsters, to fix this issue? Pri & trans will then share fluid- no problem!
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

Moparnut72

Yeah that and go one more and get rid of the stinkin primary chain. Get rid of all the chains for that matter.
kk
If you find yourself in a fair fight,
You didn't prepare properly.

VDeuce

Just installed the primary vent today; pretty easy job. Noticed a slight amount of transfer with the CVO 3-piece pushrod, though very little. This should solve it completely I think.