9 INCH REAR END ALL NEW AND BLOWS FLUID OUT VENT
 

FINISHED A 69 MUSTANG PUT A HEIDT;S REAR FOURLINK WITH BRAND NEW HOUSING,AXLES AND A CURRIE CENTER WITH 3:89 AND DETROIT LOCKER, 31 SPLINE AXLES. BLOWS FLUID OUT OF VENT, REMOVED SHORT VENT AND PUT LONG VENT WITH HOSE TO FLOOR PAN AND STILL PUSHES FLUIDOUT. CHANGED FROM SYNTHETIC FLUID TO 80W90 PER CURRIE TECH LINE AND STILL SAME PROBLEM MADE SURE WASNT OVER FULL AND NO IMPROVEMENT, EVERYTHING FITS NICE IN NEW HOUSING, AXLESLIDE RIGHT IN, CHECKED AXLE LENGTH TO MAKE SURE WEREN'T TOUCHING IN CENTER FROM BEING TO LONG AND HAS PLENTY OF CLEARANCE. ANY CLUE? BUILT TONS OF REAR ENDS AND NEVER HAD THIS PROBLEM. TALKED WITH COUPLE OF DRIVETRAIN SHOPS AND THEY HAD NO REALANSWER EITHER. :?

it has to have to much fluid and is whipping it into a pressure point and forcing it out the vent---check with your center section maker--the mass size might have alot to do with the amount you put in the rearend housing---just also try lowering the fluid in the housing and run it again :oops:

make sure the vent fitting and line both come out of the TOP of the housing straight up not at an angle 8)
i had that vent angle problem on a mud truck 9 inch and that was causing a syphoning problem of the fluid :cry:

let us know what you try and the results 8)

thank you
 

thank you for response, i already lower fluid 1/2 inch from fill plug as currie recommended, and vent is on left hand axle tube and is straight up and down, i was told to try and ad a 2nd vent to housing but still worries me that why? when never had to have 2 vents before on other rear ends that had spools and lower gears, what could make th fluid foam by chance that is the problem?

My 9" does the same thing. Always has. The 8 3/4 in my buddies rail does it too.Maybe because they are narrowed so much? I dont know.
We took the vents out,screwed in a pipe fitting with a 5/16 barb fitting and a piece of fuel line up to a el-cheapo fuel filter tied up high on the frame. Not pretty but it works.
If you find a good solution I would love to hear it since I am putting that car back on the highway soon. Thanks

If there is any kind of port on top of the ''pumpkin'' pull the fitting out of there and use that as your vent. You want to get the vent at the highest point on the housing. Don't forget to plug the vent you're now using if you're able to switch.

Looking at the rearend from the back ... where is the vent located at ?

THANKS
 

THE PORT IS IN THE DRIVERS AXLE TUBE ABOUT 2 UINCHES FROM HOUSING TO TUBE WELD

Be careful how low you get the oil in the rear. Last April I put a new gear in my truck and only put about 2 quarts of oil in it. The gear lasted 1 pass. The pinion bearing didn't get enough oil and locked up which broke the trans input shaft, busted the trans and ruined the driveshaft.
A $18 quart of oil cost me a transmission, driveshaft, 2-1350 u-joints
and a ring gear and $90 worth of gear oil. Probably close me about $2,000.
I think I was more ticked about the cost of the oil (2 quarts wasted on the first time and the 3 I had to use the second time.) than anything else.
Lesson well learned on that one :oops: :oops:


Like already said use a piece of fuel line and I put a loop to it to make sure it doesn't overflow or get water down in it.

Is the vent right above the ring gear? If so it could be flinging the oil through the vent line. Just a thought.