Installed Fairey - Big Leak

[98 HOO]

I installed a used Fairey OD in my truck this evening. Took it for a test drive and am thrilled with the difference at 55 mph. Trouble is, when I got home, there was oil dripping from the unit and sprayed all over the underside including the rear axle and tire. I pulled the interior cover, and it all appears to be coming from a small hole in the square cover plate that faces straight up at the underside of the center front seat. There appears to be a cotter pin stuck in the hole, but that obviously isn't working. I looked at RDS, and think I see the same hole in their photo.

Is this type of leak normal? Is it alright to plug that small hole, or is it a vent? If it is a vent, has anyone used a length of hose to raise the vent and help to prevent the oil loss?

Thanks for the help!

[LaneRover]

It is a vent, I have heard of folks putting a hose in there. Is there a chance that you overfilled?

[98 HOO]

I don't think there is much of a chance I overfilled - I started with a 1 liter bottle and put 1/2 of it in there. I believe they take 1/2 liter?

[stomper]

You definitely overfilled something. There should be a little weeping from the hole, but the spray you are describing is obviously excessive. Pull the dipstick, and make sure there is the proper amount of oil in there. It is a small resivior, so check it often, and top up as needed, but don't overfill.

[I Leak Oil]

Yes that is the ingenious vent hole. Yes they leak from that hole, even if you have the right amount of oil in it. Yes, you can put a fitting and a vent hose for better results, just make sure it's in the right location and you have a baffle on the inside or the oil will come out the vent tube. The seal on the input gear could be shot allowing the transfer case oil to enter the O.D. unit. If you check the oil level and it's more than what you put in then you have a bad seal.

[luckyjoe]

I agree to check if the OD is overfilled. Some vent hole oil is normal, but yours does seem excessive. If you pull the OD top cover, make sure there is a baffle below the hole, or oil will be thrown directly at the vent (and could result in the excessive loss you're experiencing).

This pic shows the Fairey top plate baffle on the LEFT, inverted. On the RIGHT is the new brass baffle I made, to be fitted with a new top plate and re-positioned breather (see the second photo below).


Here is a picture of the breathers I installed, routed from T-case, to OD, to Gearbox, to engine bay.


Several years in operation and no oil in the breather tubing.

Just to be thorough, here is the t-case top cover and baffle. In final configuration I used a 90deg. fitting since the T-case was the origin of the breather loop.


Regards,

[98 HOO]

Good news is that I do have a baffle.

There is a notch about 1/2" from the bottom of the dipstick - is this where I am supposed to fill to? If not, where on the dipstick should it be filled to? I checked, and with the 1/2 liter, it is almost to the top of the dipstick, so it must be overfilled.

Thanks again

[stomper]

That notch is the fill mark. Drain out the excess oil, and you should be good to go. FWIW, I keep my dipstick nut finger tight, and check the level of the fairey unit whenever I check the engine oil level. Maybe that is overkill, but with all the discussions of burnt up overdrives, I figure it is cheap insurance.

[98 HOO]

Thanks for all the help. I will get it sorted-out this evening.