7.5 rear - plastic vent help?

[sheriffd2]

Hey all, hoping for some expertise and maybe advice...

I'm building a T with a Chevy 10-bolt 7.5 rear end (I know, maybe not the be-all end-all greatest rear choice, but it's what I have and it's already set up with brackets, brakes, etc)... anyway, I spent several hours today with wire cup wheel, sander, wire brush, degreaser etc. really cleaning it up (remarkable the dirt, grime, sludge etc built up on the thing), and during the cleanup process I noticed the little plastic tube on the top of the diff. At first I thought it was some kind of filler tube, but a little research looks like its actually a vent.

So, what's the question? Well, I actually found the thing accidentally with a sanding disc on an air die grinder. Ugggh, needless to say, I buzzed a bit of it off. So, is this something I need? Can it be easily replaced, if so where do I get a replacement and how do I remove it? Plugged? Or another suggestion?

Really appreciate any help :thumb: Thanks in advance!!!

 

[Ted Brown]

Hey all, hoping for some expertise and maybe advice...

I'm building a T with a Chevy 10-bolt 7.5 rear end (I know, maybe not the be-all end-all greatest rear choice, but it's what I have and it's already set up with brackets, brakes, etc)... anyway, I spent several hours today with wire cup wheel, sander, wire brush, degreaser etc. really cleaning it up (remarkable the dirt, grime, sludge etc built up on the thing), and during the cleanup process I noticed the little plastic tube on the top of the diff. At first I thought it was some kind of filler tube, but a little research looks like its actually a vent.

So, what's the question? Well, I actually found the thing accidentally with a sanding disc on an air die grinder. Ugggh, needless to say, I buzzed a bit of it off. So, is this something I need? Can it be easily replaced, if so where do I get a replacement and how do I remove it? Plugged? Or another suggestion?

Really appreciate any help :thumb: Thanks in advance!!!

Well I can't see it, but you do need the breather, or the grease will work it's way out through the seals onto your brake pads and drums... if that hole is tapped into the housing, then you could make your own, if you can not find a stock part at the parts store, or maybe even the web... Alway best to clean ALL THE CRUD off first with hot soap and water or solvent?? then MAYBE a sander, and then sand correctly, WITH the tube, not against or across the length of the tube, as this will leave dips in the tube and they will be hard to hide without a lot of filling, grinding is an art form... Good luck with your project, and yes, you are right to use the rear you have... Go slow, enjoy the ride..

 

[RPM]

We have run into similar situations and you can buy and aftermarket vent. When we narrowed our Dana 60 the tube that got cut out was the section that had the vent. So we just drilled and tapped a new hole and installed an aftermarket vent.

Here is one I found just looking on Google.

http://www.yearwood.com/index.cfm/page/ptype=product/product_id=834/prd834.htm

 

[Hotrod46]

I used a screw in vent from McMaster Carr, an industrial supplier. They are listed as tank vents. They screw in with pipe threads and have a heavy duty bronze element that acts as a screen. Mine was gold cad plated and low profile.

My 7.5 S10 rear had a straight hole for a press in plastic vent in the center section that was not tapped. I believe I used a 1/4" pipe tap.

If you decide to tap the hole, be sure to catch all the metal shavings from the tapping process or you'll be replacing lot's of expensive internal rearend parts. Mine was disassembled for a gear swap when I tapped it.

Here is a link to the McMaster Carr page. The vents are about half-way down the page.

http://www.mcmaster....k-vents/=65op6t

The vent is the small gold finished piece in the lower right of the pic.


Mike

 

[railroad]

Okay Hotrod46, you posted that picture just to drive me crazy. What is the linkage and box attached to the back of your axle.
I have convinced myself, it cannot relate to dampning.

 

[Hotrod46]

Okay Hotrod46, you posted that picture just to drive me crazy. What is the linkage and box attached to the back of your axle.
I have convinced myself, it cannot relate to dampning.

Railroad, I'm running air suspension on the rear. The box is a control for auto leveling. It "reads" whether the arm is high or low and either adds or releases air to maintain ride height. GM put the boxes on lots of luxury type cars from the 60's through the 90's (that I know of). Ford used a similar setup on Lincolns.

The system works well and keeps just enough air in the bags. I think my car rides about as good as a 2000 lb straight axle car is going to. I've made 450 mile days in it with no problem and the car always sits at the same height loaded or empty.

Edit - Actually, my system is a hybrid. The only thing from the original GM car. The control valves are industrial and the compressor is an after market motorcycle size air suspension piece.

Mike

 

[railroad]

Thanks for the explaination. Sounds like a class set up.

Jegs carries the vent for less than $5 and comes in 1/8 and 1/4 NPT.

 

[sheriffd2]

Guys, Thank You! To my surprise I was actually able to find a local dealer who had the part in stock (actually even surpised him!).

Seven bucks and change, so not too bad. got the rear about 80% finished up today, tomorrow, when I can get a good look in the daylight I'll inspect the new paint and should be able to button it all up.

Really, thanks again, I love this forum, great group!