Ok guys, any advice here is appreciated. A few weeks ago I noticed the rear end had some substantial oil over the pumpkin and axle tube. Definitely not normal amounts. Far from it, actually lol. Thats why I say it's volcanic. The extent of the oil is what caught my attention initially. I wiped it all down in an effort to locate the source once it leaked again. Didn't take long before it was apparent that the leak was from the driver side axle tube breather valve. I tried doing some initial research and found a mustang forum that mentioned this being a problem on their cars. Their solution seemed much more simple. Removing the breather valve, adding some tape and reinstalling. I don't think thats my problem, but reading about their problems did make me realize I'm not the only one in this position and that it's maybe more common than it should be for such a popular rear end. Anyway, Background on the rear setup on my truck is this; The previous owner built the suspension/driveline and manufactured their own Ford 9" rear housing, Strange 9" Ford nodular iron third member w/ 3.50 gears, Strange 31 spline axles. The breather valve on the axle tube is more like a spring or pressure valve though and not a breather valve like I'm used to seeing. So basically, my question is this. Does anyone have any advice as to why I'm spewing gear oil everywhere? I mean, aside from the oil heating up, pressurizing in there and needing to blow off some steam. Should I assume this is as simple as an overfill issue? Or is it a sign of something potentially more serious happening back there? Should I change out the vent spring? First pic, I'm holding it up. The spring definitely has tension in it. It's not stuck open like that. I just did that for the picture.
It appears that you are threaded into a boss, if it were mine I would attach a hose and get it well above the axle with a filter. Here's an example using a metal small diameter fuel filter to keep the dirt out.
10-4! Kinda like how I did the diff breather on my Tacoma. I did it there for off roading purposes as to not get water in the diff. But same concept. I installed a union and ran some hose up high with the breather at the end. I'll give that same setup a try here. I was so focused on the driver's side I didn't double check but thought this truck has one on each side. So I'll install one on each side and see what happens. Sent from my iPhone using The H.A.M.B. mobile app
Two things come to mind. One is to make sure that the rear end is not over filled. Over filling will cause a multitude of problems leaking from pressure buildup is one of them as well as blown axle seals. It is also a parasite and will rob you of usable torque. Another thing that comes to mind is that your breather valve doesn't come open until you build pressure so it is not really a breather and once you build enough pressure for it to come open it is going to spew. You ay try a more common breather, they let the pressure off way before it become a problem.
..............................I think 'beaner has it right. Instead of a "spring" loaded vent, why not just a vent?
Thanks pork! The rear end has about 2,500 miles on it since being built so I want to change the fluid anyway. The PO didn't have much information at all for me when I bought this, so a lot of these things have been guessing games for me. Planning to use 75w140. I haven't started to research it, but since it came up....With a custom rear housing like this, do I still fill it to the fill hole? That fill hole is damn near at the top of the housing. Or should I go w/ whatever capacity is standard for this rear end? Got me! I was wondering the same thing. I've never seen this style before, and didn't know if there was a reason for using this instead of a standard breather valve/cap.
Fill to the fill hole and if you are using a Strange chuck use what Strange suggests. The size of the housing should not have any effect on your fill height, it may take more then a stock housing to fill it but the fill height should be the same.
DON'T fill it to the fill hole on the back. That big hole is for ease of pouring in the lube. Fill it to the pipe plug hole that should be on the side of the Strange chunk. The lube level should be just above the pinion shaft.
You said you might install a vent in the other side as well. Why? A 9-inch should be open the whole way inside and only one vent needed.
Only because there's already one on that side. I wouldn't be tapping a new one in. Sent from my iPhone using The H.A.M.B. mobile app
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