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Rear diff vent

diesel_lv

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Rebuilt my rear diff. 8-3/4, 3.73 w sure grip. I'm getting a lot of oil blowing out of my diff vent on top. My nice clean diff is now caked w oil n dirt. Is this normal? If so, is it possible to run a hose from it up higher?
 
Short answer is yes you can extend it.
Lots off off road trucks do to keep water out.
I got to ask though is it over filled ?
 
Short answer is yes you can extend it.
Lots off off road trucks do to keep water out.
I got to ask though is it over filled ?
No, not over filled. I'll get some rubber tube n a vent filter and mount up at upper shock mounting area.
 
No, not over filled. I'll get some rubber tube n a vent filter and mount up at upper shock mounting area.

I did this on my high speed car. Works great. Mini breather tanks are available if you want to get fancy. Be sure to have a loop of rubber hose if you mount it to the body.
 
Before I pulled my diff the vent was always wet. Never added any fluid as it always seemed to seep out the vent.
Pulled diff and axles and had Tucson Differential rebuild. Filled until it puked with 85w140 conventional per Tucson Differential recommendation. Vent is dry?
Pumped out 7 pints at 500 miles and filled with fresh gear oil. Vent is still dry.
Not sure why it was always wet Before?
 
I read during my research that over time the vent goes bad and will let oil out. May buy a new factory one. But for now do a high vent w filter.
 
Rebuilt my rear diff. 8-3/4, 3.73 w sure grip. I'm getting a lot of oil blowing out of my diff vent on top. My nice clean diff is now caked w oil n dirt. Is this normal? If so, is it possible to run a hose from it up higher?
I get this in my red car too. Mine was filled to the edge of the plug.
 
I get this in my red car too. Mine was filled to the edge of the plug.
Yep, I fill to the edge. Have had to refill it twice. Hoping high vent hosevw filter will stop it n quit coating the axle w oil
 
Is the vent any good? Can you blow air out of it? If not, replace.
 
I tried a long hose tied up as high as I could. Still leaked. I put a fuel filter in the hose at the end-still leaked. I finally solved the issue with a bellows. They sell them for off road vehicles. This was on my 65 Coronet-bone stock rear axle.
Mike
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Nobody should need to extend their vent or alter it in any way. Something tells me the diff fluid is too full.
 
Is the lube synthetic ? I don't know much about synthetic but is the viscosity thinner causing vapor to leak out vent?
 
Mine all mist and they're not overfull and have dino oil in them. All the vent is is a hollow stud with a cap staked overtop. Not sure how one could go "bad".
 
My '66 has the original vent, car goes 126 in the quarter - dry as a bone. That is a strange issue.
 
They do, that’s why companies sell new ones.
 
69 had the issue when the sure grip design changed and in 70 the vent was moved away from the ring gear as a solution. Modern lube has made the problem worse and changing the breather vent won't fix it. I had to use a catch container that allowed the lube to drain back when the car stopped moving. I tried 4 different vents and found an NOS 69 sure grip unit for my car and it still did it. Cleaning the gas tank and rear of the car every time it is driven really sucks.
 
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