Differential fluid change instructions?
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Differential fluid change instructions?
A few questions I have below before I drain and refill my rear diff on my '87 6.9. Any other pointers appreciated. Thanks.
Gear oil weight?
Capacity (almost positive it's a factory diff cover)?
Resealing the cover? specifc gasket or liquid gasket?
Torque on the diff cover bolts?
Gear oil weight?
Capacity (almost positive it's a factory diff cover)?
Resealing the cover? specifc gasket or liquid gasket?
Torque on the diff cover bolts?
Postmaster
Joined: Apr 2008
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A few questions I have below before I drain and refill my rear diff on my '87 6.9. Any other pointers appreciated. Thanks.
Gear oil weight?
Capacity (almost positive it's a factory diff cover)?
Resealing the cover? specifc gasket or liquid gasket?
Torque on the diff cover bolts?
Gear oil weight?
Capacity (almost positive it's a factory diff cover)?
Resealing the cover? specifc gasket or liquid gasket?
Torque on the diff cover bolts?
1) I used 80W90 oil.
2) factory service manual says 3.5 qts capacity, I put in a bit over 4 qts.
3) you can just black RTV and no gasket, but I opted for a new Felpro paper gasket ($6) and black Permatex gasket maker on both sides of that, works absolutely great.
4) dunno the factory torque specs, but those are some 5/16" grade-8 bolts there, so you can tighten them down pretty good.
You drain by loosening the bolts for the diff cover, then when the pumpkin is empty pull the cover entirely and jack first one side of the axle up, then drop that side and jack up the other side - you do this to til the axle so all the old oil and from the axle tubes leaks back into the pumpkin. After all is drained you're about ready to reassemble it and fill it up, but before that and while the cover is still off make it a point to check the torque on the ring gear to the diff - they are known to get loose on some trucks, and that ain't no fun at all. Only then you put the gasket and the cover on, and tighten the bolts back in. Filling is done through the inspection hole on the driver side of the pumpkin, that plug takes a 3/8" drive ratchet or breaker bar. I found it easiest if I just attach a hose to the new gear oil bottle, then feed the end of that hose inside that inspection hole.
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From: Jupiter
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Postmaster
Joined: Apr 2009
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From: Malahat/Cowichan Valley
because it relates to this thread, would water in a diff make the fluid a weird tan color? Had this question from a fella here at work, apparently it is like cardboard box color. I guessed water. But with that, how would that happen??
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From: Maine (NorCal Native)
Yes, And it can happen several ways...
A couple ways:
The Housing is vented ... Is the vent hose missing!
Typical wheel seals can leak in but not out ... (Junk, Single lip seals)
Single lip seals can allow water in when submerged!
We found because of my annoying cleaning ritual! The pressure washer was blowing water in through the wheel seals! Went to double lip seals and have not had a problem since.
-Enjoy
fh : )_~
A couple ways:
The Housing is vented ... Is the vent hose missing!
Typical wheel seals can leak in but not out ... (Junk, Single lip seals)
Single lip seals can allow water in when submerged!
We found because of my annoying cleaning ritual! The pressure washer was blowing water in through the wheel seals! Went to double lip seals and have not had a problem since.
-Enjoy
fh : )_~
Postmaster
Joined: Apr 2009
Posts: 4,086
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From: Malahat/Cowichan Valley
Ya i know what you mean with the vents, they are both sealed and up high in the engine compartment. It is his front diff that has the nasty color. So as for the double lip seals, can you give me a run down on how to do it so i can help him this weekend? Thanks for the relpies guys!
Methanoholic
Joined: Mar 2009
Posts: 6,442
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From: Maine (NorCal Native)
Not much to elaborate on, They are just a better seal, they have two sealing lips, the inner one keeps fluids in and the outer one keeps water and what not from getting in.
I typically get my seals from Seals Unlimited, I think they can be found online, they are here in Maine.
-Enjoy
fh : )_~
I typically get my seals from Seals Unlimited, I think they can be found online, they are here in Maine.
-Enjoy
fh : )_~
Post Fiend
Joined: Nov 2003
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From: Nutter Fort, WV
My mud truck friends here made an interesting observation.
The guys that drove to the events were eating bearings and other axle internals.
The guys that trailered their rigs were not.
Same basic trucks, same mud holes so what was going on.
The trucks that were driven had hot drivelines from the drive, so when they hit the mud and cooled the axle housing off fast, the low pressure it created inside the housing was sucking in muddy water and grit.
The guys that trailered had cold drivelines, so they did not have the same problem.
Same thing happens when you ford a stream with a truck that has been driven several hours before you got to the stream.
Even if you have the vent hose up high, it is probably to small to let in enough air when you run a hot axle down in 50 or colder degree water.
So the difference in pressure is made up with water sucked in the pinion seal and axle seals.
The guys that drove to the events were eating bearings and other axle internals.
The guys that trailered their rigs were not.
Same basic trucks, same mud holes so what was going on.
The trucks that were driven had hot drivelines from the drive, so when they hit the mud and cooled the axle housing off fast, the low pressure it created inside the housing was sucking in muddy water and grit.
The guys that trailered had cold drivelines, so they did not have the same problem.
Same thing happens when you ford a stream with a truck that has been driven several hours before you got to the stream.
Even if you have the vent hose up high, it is probably to small to let in enough air when you run a hot axle down in 50 or colder degree water.
So the difference in pressure is made up with water sucked in the pinion seal and axle seals.
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jberylecrider
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