Diesel Place banner

1 - 14 of 14 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
Fixing to drain the front and rear diffs and go to synthetic and read on here about changing the front vent cap to the white one#12479296. I peeked under mine and it has a white one and not the black that needed to be swapped when you go to synthetic. Hate to spend money on a part I dont need. Just wondering if any of you have this as well. My truck is an 06, maybe GM put the white ones in now from the factory?? What should I do?
Thanks,
 

·
Registered
Joined
·
5,255 Posts
Ditto. I think the white cap was standard starting with LLY in '04, not sure, but they absolutely are standard on '06.
 

·
Registered
Joined
·
1,460 Posts
what does the white cap breath better or what
 

·
Registered
Joined
·
17 Posts
Discussion Starter #5
Ok thanks guys, I will pull it in the shop tomorrow night and get it changed.:D
 

·
Registered
Joined
·
3,464 Posts
iirc, the white cap has a different type of o-ring that is compatible with synthetic fluids. but i don't buy it.

if i would have had the black cap to start with, i wouldn't have changed it for synthetic.
 

·
Registered
Joined
·
1,460 Posts
iirc, the white cap has a different type of o-ring that is compatible with synthetic fluids. but i don't buy it.

if i would have had the black cap to start with, i wouldn't have changed it for synthetic.
i dont think i would change it either a seal is a seal untill it starts to leak or something then iwould change it
 

·
Registered
Joined
·
303 Posts
It may also be possible that GM put the white vent cap on the later model trucks because the front differentials have synthetic fluid inside. May want to check before you change it.
Mark
 

·
Registered
Joined
·
1,801 Posts
I just changed my front tonight. I checked before I did the job and it had the white cap. Very easy job. Just don't be surprised that it is yellow coming out the front and black coming out the back of the G-80.
 

·
Registered
Joined
·
5,255 Posts
Ditto.... front is a dino 80w90, rear is "Grapejuice" 75w90.
Replace both with Mobil-1 75w90 and be happy.

Dunno why the front looks so bad.... it looks like it's loaded with water.
Some speculate that it's "contaminated" with a material they use for testing gear mesh.
 

·
Registered
Joined
·
1,460 Posts
Dunno why the front looks so bad.... it looks like it's loaded with water.
Some speculate that it's "contaminated" with a material they use for testing gear mesh.
is that why it is yellow from the stuff they use to check gear mesh
 

·
Registered
Joined
·
65 Posts
The white cap has a metal vaine on it to wieght it down better to keep the gear lube from being forced up the vent hose. The yellow in the lube is glow in the dark die for leak checking
 

·
Registered
Joined
·
17 Posts
Discussion Starter #13
I just changed my front tonight. I checked before I did the job and it had the white cap. Very easy job. Just don't be surprised that it is yellow coming out the front and black coming out the back of the G-80.
Yeah it looked like shiat coming out the front all yellowed up. I was thinking it looked like gear marking compound, being I have a tub of it I use setting up ring and pinions.
 

·
Registered
Joined
·
159 Posts
:lol:
Yeah it looked like shiat coming out the front all yellowed up. I was thinking it looked like gear marking compound, being I have a tub of it I use setting up ring and pinions.
man that first change freaked me out!!!! What really pissed me of was the fact that my wifes burb that I bought at the same time as my truck had the white cap and mine had the black cap!wifes burb only had quart and half, truck had little over to quarts! Valvoline syntec 75-90 in both vehiks and in both front and rears (yeah I filled them to the right levels by-the-way...)
 
1 - 14 of 14 Posts
Top