I have a slow leak at my rear third member. It’s not the drain plug, it’s definitely coming from where the third member attaches to the axle housing. If my breather is clogged, is it possible for the internal pressure in the diff to cause a leak? I ordered a new breather and will relocate it this weekend, but just curious. Trying to avoid pulling my axles to reseal the third member.
Clogged breather = diff leak?
- Thread starter BostonJon
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nevada
Senior Member
theoretically I suppose its possible, though that usually causes a leak at the axle seals. the seals are a much easier compromised point of exit than the differential. if the 3rd member is leaking currently, I doubt fixing a clogged breather is going to stop it from leaking.
dogtail
New member
It is possible. But it can just leak also. When you pull off the breather, can you blow thru it? The rear diff can build up some pressure. I once broke off my tail pipe and it was blasting at my floor, so I took a Sawsall and cut it off so it would just blow straight out muffler till I got a tailpipe. Well I didn't realize it would heat up my rear diff so much, ended up blowing out my pinion seal from heat pressure (well that's my theory), I think my breather was partially clogged also.
thegipper
New member
Your third member is probably just leaking, it happens. It certainly never hurts to check your diff breather or better yet, do the diff breather mod.
It really isn't that hard to pull the third member. Put truck on jack stands, remove wheels, pull axles, unbolt rear drive shaft, unbolt 3rd member and remove. You'll need to clean up the third member and the axle housing real good and either use some FIPG or I used Permatex "The Right stuff" which dries much quicker. Hardest part is lifting the 3rd member and getting it back in place, be careful because it's heavy AF.
It really isn't that hard to pull the third member. Put truck on jack stands, remove wheels, pull axles, unbolt rear drive shaft, unbolt 3rd member and remove. You'll need to clean up the third member and the axle housing real good and either use some FIPG or I used Permatex "The Right stuff" which dries much quicker. Hardest part is lifting the 3rd member and getting it back in place, be careful because it's heavy AF.
mtbtim
Elite Member
If you are forced to pull the 3rd member to reseal it, this video might help you out.
<iframe width="560" height="315" src="https://www.youtube.com/embed/ZMTbgY1xQKk" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
<iframe width="560" height="315" src="https://www.youtube.com/embed/ZMTbgY1xQKk" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
Already watched it twice and took some notes! Rarely do I start a project without checking your video library first
MaineRunna
Member
Axle & pinion seals are the most likely places to leak in the case of excessive pressure. Try tightening the nuts around the third member first, if that doesn't work you will have re-seal it. You can use the factory paper gasket, but I agree with thegipper on Permatex "the right stuff". Great adhesive sealant that dries fast and is instantly oil resistant.
