8 3/4” axle leak

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dart1

dart1

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Hi All,

I’ve noticed a fluid leak where the 3rd member differential carrier meets the 8 3/4” axle housing.
Wanted to get some info on who had success in stopping the leak and method they used.
Is it better to use a gasket only, or use high temperature silicone only, or use both gasket with high temperature silicone together?

Much appreciate your time and reply,
Thanks
 
I used a gasket only. No leak but those gaskets are tough to clean off around all those studs. You could clean off the leaking area with brake clean and apply a "smiley face" of black silicone. Let it sit overnight and it might stop the leak.
 
I have a leak on the top of the housing somewhere... It only leaks when I am driving and it runs down the back of the housing....cant find it for the life of me. I will have to pull the housing and strip it down this winter.
 
I have found that if the studs were removed and replaced, and not indexed in the original stud serrations. it will create a leak path. Some gear oil resistant RTV around the stud will help. A little bit goes a long way.
 
Steven190 said:
I have found that if the studs were removed and replaced, and not indexed in the original stud serrations. it will create a leak path. Some gear oil resistant RTV around the stud will help. A little bit goes a long way.
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I have resealed the carrier 3x and it still leaks. I am afraid it is a hairline crack in the housing weld
 
mbaird said:
I have resealed the carrier 3x and it still leaks. I am afraid it is a hairline crack in the housing weld
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that's not impossible. The welds on those housings were notoriously poor. I, personally, have never had one leak on me, but the welds look terrible. I've heard a few others complain about leaks at the welds.
 
if you suspect a weld leak you could pull the axles and make a plate to block them off. apply light air pressure in through the breather vent and see where it comes out. I stress light air pressure as I don't know what will happen to the pinion seal with positive pressure in the housing.

you might be able to do the same with the axles in place but the same seal warning from above.
 
Dana67Dart said:
if you suspect a weld leak you could pull the axles and make a plate to block them off. apply light air pressure in through the breather vent and see where it comes out. I stress light air pressure as I don't know what will happen to the pinion seal with positive pressure in the housing.

you might be able to do the same with the axles in place but the same seal warning from above.
Click to expand...
if you decide to try that, maybe you could use a bicycle pump, even better if it had an integral gauge.
 
Thinking leak detection, there shouls be dye you could add that is visible with a black light. Look up uv leak detection
 
mbaird said:
I have a leak on the top of the housing somewhere... It only leaks when I am driving and it runs down the back of the housing....cant find it for the life of me. I will have to pull the housing and strip it down this winter.
Click to expand...


Check around the vent. Gear oil was blowing out of mine just a little while driving. replaced it with a new one and no more leak.
Here's one at year one:. Mopar Dodge 4032798 Rear Axle Vent1966-74 A B E-Body
 
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toolmanmike said:
Thinking leak detection, there shouls be dye you could add that is visible with a black light. Look up uv leak detection
Click to expand...
I just bought some fluorescent orange dye to color the GO5 coolant for my 02 Trep. I got it from Forestry Suppliers. They have other more common colors, which show up under UV.
 
rustycowll69 said:
I just bought some fluorescent orange dye to color the GO5 coolant for my 02 Trep. I got it from Forestry Suppliers. They have other more common colors, which show up under UV.
Click to expand...
Oil and coolant dye are different. But that's ok. Get what you need.
 
dart1 said:
Hi All,

I’ve noticed a fluid leak where the 3rd member differential carrier meets the 8 3/4” axle housing.
Wanted to get some info on who had success in stopping the leak and method they used.
Is it better to use a gasket only, or use high temperature silicone only, or use both gasket with high temperature silicone together?

Much appreciate your time and reply,
Thanks
Click to expand...

Didnt mean to hijack your thread...
I added my issue just in case you have a similar issue.
 
dart1 said:
or use both gasket with RTV together?
Click to expand...

That's what I did when I built my rear.

A 1/8 inch bead is sufficient, run it in the center of the mating surface between the studs, and a bead completely around the base of each stud. Slide the gasket on, and repeat the process on the gasket............install third member.
 
Thanks Everyone for your info and knowledge. I'll try using both gasket with RTV together as Bad Sport did and hopefully stop the leak. Thanks again Bad Sport and All.
 
On a side note... ford 9" use copper crush washers under the nuts that hold the center section in. I have not seen this on mopars but might help
 
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