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Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 16, 2018 01:57PM

Ok. Im at my witts end.
Installed a rebuilt diff and trans for someone.
Everything went in without a problem. However, the diff is blowing oil out the top vent.
Usibg Sta Lube GL4 80-90
Took the trans down to verify that the gasket was installed correctly. No problem found.
Checked all the passages for blockage. Not problem found.
At the request of the owner reinstalled the original trans.
Filled again and still having same issue.
Transaxke was filled while level and was 1" or so below the fill plug.
Trans filled first. Then diff.

What am I missing?

The last time I had a situation like this it turned out to be the gear oil.
Was given GL6 . When switched to GL5 the problem went way. But was GL4 and GL5 (which is what was in it when we started)

Marco
Sun Valley Ca 91352



Edited 1 time(s). Last edit at 07/16/2018 05:02PM by MattNall.

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Re: Puking Diff Fluid
Posted by: corventure Dave ()
Date: July 16, 2018 02:20PM

Marco,

Yep, a strange one there!

I would suspect the oil also. It's an easy drain and re-fill with something else to find oil.

The other thing that comes to mind is what Diff cover is on there? I know they changed the vent location.

Years ago I tried some X-brand synthetic gear oil in a rebuilt 1966 4-spd diff. The stuff never leaked out. But it half evaporated in 18,000 miles! Talk about a strange thing to happen!

Corventure Dave

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Re: Puking Diff Fluid
Posted by: 66vairman ()
Date: July 16, 2018 03:07PM

Marco - Many years ago I recall a post about problems with the differential vent.

Found it (Matt should be proud of my search effort).

See [corvaircenter.com]

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Re: Puking Diff Fluid
Posted by: azdave ()
Date: July 16, 2018 03:14PM

Sta Lube GL4 85W90 (locally at NAPA Auto) is about all I have used in the last 10 years. No issues here.


Dave W. / Gilbert Arizona
66 Corsa 140 4-speed w/factory A/C
66 Corsa 140 4-speed
65 Corsa 140 4-speed
66 Corsa 455 Toro V8
65 Monza 455 Toro V8
65 Monza 110 Convertible
65 Monza 4DR 140 PG w/factory A/C
65 Monza 4DR EJ20T w/5-speed




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Re: Puking Diff Fluid
Posted by: davemotohead ()
Date: July 16, 2018 04:15PM

The only time I had that happen was when the units were filled too much and it came out the vent until the level went down to spec, some top covers have a splash guard next to the vent that is supposed to keep the oil from splashing out the vent. I use the same oil as AZdave.





Email me at: Dave Motohead

1960 4dr sedan caveman car
1961 Rampside (Chetside)
1962 Rampside (Barnside)
1962 Short Rampside (Shortside)
1962 Monza 700 Wagon
1963 Monza 900 coup (General Nader)

-----------------------------------
Rust Free Lancaster Ca

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Re: Puking Diff Fluid
Posted by: Timothy Shortle ()
Date: July 16, 2018 04:35PM

The top cover Mr. MotorH. is referring to is only on the late late made cars. Only on MT cars (I believe). I have seen a couple of 69 PG cars that did not have the baffle on it. I was told (by Bob Helt, R I P), that it was introduced to keep more oil on the rear pinion bearing but as a added bonus it also kept oil away from the top vent.

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Re: Puking Diff Fluid
Posted by: 66vairman ()
Date: July 16, 2018 04:43PM

Timothy Shortle Wrote:
-------------------------------------------------------
> The top cover Mr. MotorH. is referring to is only
> on the late late made cars. Only on MT cars (I
> believe). I have seen a couple of 69 PG cars that
> did not have the baffle on it. I was told (by Bob
> Helt, R I P), that it was introduced to keep more
> oil on the rear pinion bearing but as a added
> bonus it also kept oil away from the top vent.

That interesting. Makes sense.

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Re: Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 16, 2018 04:52PM

From what I can tell, correct vent. RR of cover on an EM.
Not over full.
Correct oil
Pass through holes all clear.

Im at my wits end.

(Now owner wants to go back to the diff)

Marco
Sun Valley Ca 91352

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Re: Puking Diff Fluid
Posted by: Max Roeder ()
Date: July 16, 2018 05:00PM

The following article lists too much defoamant additive in the original formulation or "sweeting" of the additive package. Amazing that too much defomant would cause foaming! I believe I would switch brands to see if same thing happens. Sometimes the mfg. does make mistakes.

[www.machinerylubrication.com]

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Re: Puking Diff Fluid
Posted by: jjohnsonjo ()
Date: July 16, 2018 05:12PM

Any chance you got some water in it. Oil and water can really whip up some foam.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa

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Re: Puking Diff Fluid
Posted by: Timothy Shortle ()
Date: July 16, 2018 05:28PM

An after thought here Marco, how about get a hold of a cover with the built in baffle and install it. Or even weld a baffle into place on your cover. Just a thought. I also use the same fluid AzDave and DaveM. use.

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Re: Puking Diff Fluid
Posted by: JimBrandberg ()
Date: July 16, 2018 08:53PM

Corvair Secrets by Bob Helt Page 254 shows 60-63 vent on the corner towards the engine on the passenger side. 64-65 on the corner towards the transmission on the drivers side. 66-69 in that same corner but with a baffle added. I don't know if this helps but I read the above post and then was reading the book a few minutes later.
I generally use the 85/90 Sta-Lube like above. I did try Redline GL-4, if I remember right it's 75/90 and thought about switching whenever I start from empty, seems like good stuff.
I wish I had something that would help, I feel your frustration.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 17, 2018 10:46AM

Changed brands from sta lube to STP.
My only other option is to try a differnt top cover.

Marco
Sun Valley Ca 91352

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Re: Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 17, 2018 05:03PM

Thinking on this more.....
Im begining to think that perhaps things are to tight in the diff....
Will know once i pull the pack again. Will check clearances and measure pinion torque with the inch pound beam torque whrench.

No water in oil. Irs a fresbnbn rebuild. Oil replaced twice now...

Marco
Sun Valley Ca 91352

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Re: Puking Diff Fluid
Posted by: Brizo ()
Date: July 17, 2018 07:56PM

I've cut out and welded a shield around several early (on right rear of cover)diff cover vents when I didn't have a late cover to use. The only EM diff I've ever seen puke myself was with a PG on a very hot day at 70 mph after a few sweeping curves. I've never seen evidence of the diffs being sensitive to the type of lube used.

Dan Brizendine,
'64 8door Greenbrier 140 PG. "In beautiful Wanamaker Indiana...with one stop light and 5 pizza shops"

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Re: Puking Diff Fluid
Posted by: steve c goodman ()
Date: July 17, 2018 08:18PM

I have only had one similar to this, a 64/pg. It would push gear lube up the dipstick tube (axle check tube). I had never seen it before and actually asked Craig Nicol for advice, he suggested the vent on the diff cover was plugged. I pulled the diff cover in the car and sure enough there was a gummy substance around the vent and it was plugged. I actually saved that cover to show the customer and simply replaced with a clean cover and gasket and it has never happened since. In fact the car has been to Palm Springs Toss and Okla last year to Roundup plus several Tri-state meets plus normal driving. I never figured out what the gummy junk was and tossed the cover because I didn't trust even tanking it.

Only reason I am relating the story here is in case someone searches later for similar problems they can read about it.

GOOD LUCK Marco fixing yours.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC

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Re: Puking Diff Fluid
Posted by: richard1 ()
Date: July 18, 2018 10:29AM

Most common causes of foaming are
-oil level too high (most common cause)
-oil too thick
-residuals of cleaning fluids
-too little anti-foam in oil
-too much anti-foam in oil (anti-foam is actually like alka seltzer, making bubbles big enough to break)

BTW, 85W-90 is really awfully thick for a Corvair, and "evaporation"? I once had a customer who told me that. The Chevron engineer with me, upon hearing that, broke up laughing. Said the transmission would have to get up to about 500ºC for that to happen. I later found that the driver was just getting "receipts" along the way for oil he never bought so he could pad his pocket.

Restoration in Bolivia
Richard's Mini Pickup
Richard's Corvair
Richard's Renault Dauphine

Selection of the Right Motor Oil for the Corvair
Selection of the right transmission oil for the corvair
How to polish and restore stainless and aluminum trim

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Re: Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 18, 2018 11:14AM

Richard. What is recomended then as far as the weight of the oil?
Ive used 80 90 in the past with no boil over.

As fas as contamination, ive dumped and replaced the fluid once already.
I can do again with a different grade if needed.

Marco
Sun Valley Ca 91352

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Re: Puking Diff Fluid
Posted by: richard1 ()
Date: July 19, 2018 12:02PM

75W-90 is what makes mine shift the best. 80W-90 is often used, and I used that first, but the first few shifts of the day, even in the 80's (F), hat to be slow.

Restoration in Bolivia
Richard's Mini Pickup
Richard's Corvair
Richard's Renault Dauphine

Selection of the Right Motor Oil for the Corvair
Selection of the right transmission oil for the corvair
How to polish and restore stainless and aluminum trim

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Re: Puking Diff Fluid
Posted by: Marco_a_p ()
Date: July 19, 2018 05:17PM

Dumped fluid again and refilled. 80w90.
Took for a good 20 mi freeway drive hitting about 70 mph (per phone GPS set to HUD mode on the dash)
A little "sweat" on the diff top cover (but might be residue from my last clean up effort)
Wipped down again the best I could with a rag and brake clean. Will have the owner drive it around for a week and we will check again for fluid venting.
Will drain one more time and refill if it continues to sweat.
It all seems to point to some kind of contamination. Of what what and how is uncertain.

Marco
Sun Valley Ca 91352

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