Rear Diff Pressurized?

nicktechla · 12-22-2020, 12:33 AM

When you guys have changed your rear diff fluid, did it sound like it was under pressure? Like when you loosened the plug did it sound like it was relieving pressure? I'm just wondering if maybe the breather isn't working on my diff.

waterman · 12-22-2020, 12:40 AM

Top plug first, two change outs in a semi-quiet garage...nothing here.

Was your eLSD hot?

nicktechla · 12-22-2020, 12:41 AM

Quote:

Originally Posted by waterman

Top plug first, two change outs in a semi-quiet garage...nothing here.

Was your eLSD hot?

no it was pretty cold. I did go to the track on Saturday though. I didn't open the top plug first, I just took the bottom one out and it had some pressure in it for sure. So I was just wondering if the breather isn't working, maybe it's just normal.

waterman · 12-22-2020, 12:43 AM

Quote:

Originally Posted by nicktechla

no it was pretty cold. I did go to the track on Saturday though. I didn't open the top plug first, I just took the bottom one out and it had some pressure in it for sure. So I was just wondering if the breather isn't working, maybe it's just normal.

Interesting...keep us posted.

nicktechla · 12-22-2020, 12:44 AM

Quote:

Originally Posted by waterman

Interesting...keep us posted.

Will do! It was leaking before, so I was thinking maybe the breather wasn't leaking the pressure and pushing out some fluid. Just a theory. I'm put new gaskets on the plugs. So I'll see how it does and if it has pressure next time. I'll take the top plug out first.

waterman · 12-22-2020, 12:53 AM

Quote:

Originally Posted by nicktechla

Will do! It was leaking before, so I was thinking maybe the breather wasn't leaking the pressure and pushing out some fluid. Just a theory. I'm put new gaskets on the plugs. So I'll see how it does and if it has pressure next time. I'll take the top plug out first.

I always pull the top plug first because of a nightmare situation that I had many years ago.

I've not noticed an off-gas up top of my diff, but I was not really looking for it. with that said, this is my first experience with an eLSD.

nicktechla · 12-22-2020, 12:57 AM

Actually maybe it was under a vacuum actually. When I loosened the bottom plug it made a sucking sound, and didn't spray fluid.

UnknownJinX · 12-22-2020, 01:05 AM

There was some hissing when I opened the top drain plug on mine.

Curious about that as well.

waterman · 12-22-2020, 01:06 AM

Negative pressure is definitely a different animal.

I'm interested to see what you find.

Keep us posted.

nicktechla · 12-22-2020, 01:07 AM

Quote:

Originally Posted by UnknownJinX

There was some hissing when I opened the top drain plug on mine.

Curious about that as well.

maybe it's perfectly normal?

foshjowler · 12-22-2020, 08:12 AM

Funny, just changed mine last night, and noticed the same thing. So it's not an elsd thing. I couldn't tell you if it was pressure or vacuum, but it did make that hissing sound.

Rnovrit · 12-22-2020, 11:52 AM

Just bit of advise. Always take the filler plug out first. Not only will this relieve any pressure and save a mess it will save you a possible massive headache. I have had many times in the past on vehicles where the filler plug is either seized in the housing or some goofball before me has stripped it out. If I had pulled the drain plug first, there would be no way to refill the vehicle. Hope this saves one of you guys in the future.

Timbo-1LE · 12-22-2020, 12:16 PM

Mine does it, would not worry.

clg82 · 12-23-2020, 12:59 AM

Quick question on refilling your differential as I have to do mine soon for my break in period....can you reach everything you need to without jacking up the car? Or do you have to jack up the front and rear level so that you can fill it up properly?

12-22-2020, 12:33 AM	#1
nicktechla Drives: 2012 Porsche 911 Turbo S Join Date: Jan 2017 Location: Los Angeles, CA Posts: 1,776	Rear Diff Pressurized? When you guys have changed your rear diff fluid, did it sound like it was under pressure? Like when you loosened the plug did it sound like it was relieving pressure? I'm just wondering if maybe the breather isn't working on my diff. __________________ IG: 2fast2nick -- Current -- 2012 Porsche Turbo S - PDK - Basalt Black Metallic -- Past -- 2017 Camaro ZL1 Coupe - Red Hot - A10, PDR - HRE P101 2015 Mustang GT PP - Whipple Supercharger

12-22-2020, 12:40 AM	#2
waterman Drives: Grandad's C2 L89 Join Date: May 2017 Location: 2051.50N 15629.60W Posts: 1,711	Top plug first, two change outs in a semi-quiet garage...nothing here. Was your eLSD hot? __________________ 2018 ZL1 1LE sw/PDR

12-22-2020, 12:57 AM	#7
nicktechla Drives: 2012 Porsche 911 Turbo S Join Date: Jan 2017 Location: Los Angeles, CA Posts: 1,776	Actually maybe it was under a vacuum actually. When I loosened the bottom plug it made a sucking sound, and didn't spray fluid. __________________ IG: 2fast2nick -- Current -- 2012 Porsche Turbo S - PDK - Basalt Black Metallic -- Past -- 2017 Camaro ZL1 Coupe - Red Hot - A10, PDR - HRE P101 2015 Mustang GT PP - Whipple Supercharger

12-22-2020, 01:05 AM	#8
UnknownJinX Drives: 19 Chevrolet Camaro 2SS 1LE Shock Join Date: Apr 2020 Location: BC, Canada Posts: 1,947	There was some hissing when I opened the top drain plug on mine. Curious about that as well. __________________ Current: 2019 Chevrolet Camaro 2SS 1LE M6 Shock GM Performance Intake and that's it, because driver mods before car mods Past: 2009 Mazda RX-8 GT M6 Velocity Red Mica (Sold) 2015 Chevrolet Corvette Z51 2LT M7 Velocity Yellow Tintcoat (Flood totaled)

12-22-2020, 01:06 AM	#9
waterman Drives: Grandad's C2 L89 Join Date: May 2017 Location: 2051.50N 15629.60W Posts: 1,711	Negative pressure is definitely a different animal. I'm interested to see what you find. Keep us posted. __________________ 2018 ZL1 1LE sw/PDR

12-22-2020, 08:12 AM	#11
foshjowler Drives: 2017 Camaro 2.0T, 91 Miata Join Date: Jan 2020 Location: Raleigh, North Carolina Posts: 505 View My Garage	Funny, just changed mine last night, and noticed the same thing. So it's not an elsd thing. I couldn't tell you if it was pressure or vacuum, but it did make that hissing sound. __________________ 305 BFG Rivals FTW Youtube Channel

12-22-2020, 11:52 AM	#12
Rnovrit Drives: 2018 NFG ZL1-1LE Join Date: Jun 2018 Location: Near the water Posts: 354	Just bit of advise. Always take the filler plug out first. Not only will this relieve any pressure and save a mess it will save you a possible massive headache. I have had many times in the past on vehicles where the filler plug is either seized in the housing or some goofball before me has stripped it out. If I had pulled the drain plug first, there would be no way to refill the vehicle. Hope this saves one of you guys in the future.

12-22-2020, 12:16 PM	#13
Timbo-1LE Drives: 2017 SS 1LE Join Date: Mar 2017 Location: Florida Posts: 617	Mine does it, would not worry.

12-23-2020, 12:59 AM	#14
clg82 Banned Drives: 2020 Camaro ZL1 Join Date: Oct 2020 Location: Texas Posts: 1,724	Quick question on refilling your differential as I have to do mine soon for my break in period....can you reach everything you need to without jacking up the car? Or do you have to jack up the front and rear level so that you can fill it up properly?

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