Dana 44 front differential vent

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Dlieb

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Hello, new to the group and to working on square bodies. Just purchased a '74 GMC K2500 and noticed the front differential (Dana 44) vent is a piece of brake line that had been caulked in! I'm trying to find the original type vent but can only find (expensive) kits for attaching hose to route the vent higher. My truck will likely never leave the road so I'm not concerned with deep water. Can anyone point me to a source for whatever was there originally?
 

bucket

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Originally it would have been a nipple that was lightly pressed into place. One option would be to tap the hole for an NPT nipple to thread in.
 

ali_c20

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Welcome from Austria.

I would buy a threaded fitting with hose barb and tap the hole like Bucket said.
Attach a piece of hose with a vent valve to the fitting (the cheap plastic thingies). You don't want moisture or water in your diff.
 

PrairieDrifter

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I tapped mine. I believe it was 1/4 npt. Take a chunk of shop towel and shove it down to the bottom then you may have to run a drill bit in the hole, just barely have to upsize for 1/4npt. Tap, and run a shop vac over it real good.

There should be a metal line under the oil pan, on the engine crossmember, that goes up to the core support. With a vent valve on the end of a hose.

5/16 hose
 
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75gmck25

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Mine had a hole with a hose nipple pressed in, and it had popped out of the hole. I used JB weld on it, pressed it in firmly, and it’s been that way for at least 20 years.
 

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Just drained 2 + quarts of milkshake from a Dana 44 on the K5 thats mated to the 57. Detective work also found granite sand. All due to major axle seal failure and launching a boat last April. Just a tad of rust on the ring gear. Camping receipt in the glove box confirmed it all.
Haven't found any vent, but replaced shoes, drums, lines,bearings, seals.
 

PrairieDrifter

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Just drained 2 + quarts of milkshake from a Dana 44 on the K5 thats mated to the 57. Detective work also found granite sand. All due to major axle seal failure and launching a boat last April. Just a tad of rust on the ring gear. Camping receipt in the glove box confirmed it all.
Haven't found any vent, but replaced shoes, drums, lines,bearings, seals.
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Dlieb

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Thanks all, I wasn't aware that the hole is not threaded. I'll tap it when changing the gear oil.
 

PrairieDrifter

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Thanks all, I wasn't aware that the hole is not threaded. I'll tap it when changing the gear oil.
The hole is hidden behind the carrier bearing. A shop vac and the paper towel trick. Unless you pull the carrier.
 

Copymutt

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I checked that spot this AM. Appeared to be solid weld or cast. I’ll take another look., thanks.
 
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