1967 Midget rear end leaks oil

[Gunner]

My 1967 Midget started leaking rear end fluid onto my wire wheels a few weeks ago. Not a bad leak... but just not right. I removed drum, large retaining bolt and lock washer, pulled the hub and axle... complete clean up... etc. The paper gasket looks new as do the brakes, drums, rubber O-Ring and bearings and axle seal. What did I miss? the axle fluid appears to be leaking from the center of my rear hub where the knock off tightens. Can fluid leak out the center of the hub?
Thanks
Gunner

 

[drooartz]

No answer for you, but I'm curious as to the cure myself. Tunebug's got this problem as well, though I've got disk wheels.

 

[bugimike]

Leaking from the center of the axle-flange Drew?

 

[drooartz]

Haven't checked that closely yet, but the wheel and rear 1/4 panel show oil/grease marks.

 

[Sarastro]

There's an oil seal and that strange o-ring/gasket combination. (I say it's strange because, in any ordinary situation, one or the other would be enough, no need for both.) If all these are holding, the sucka just doesn't leak. So, one of these has to be leaking. All three of them won't cost you much, so I'd just replace all three. AND, especially, check the mating surfaces to make sure they're smooth, flat, and unscratched. Especially where the oil seal contacts the rear axle body--this should be really smooth. The oil seal also has to be pressed into the hub correctly; if it's cocked or anything like that, it may not seal properly. Finally, the AH service manual makes a big deal over the fact that the gasket must be at least 10 mils thick. If someone made one of these by hand, it might not be right. Frankly, I suspect that this gasket does the real job of sealing; I can't imagine why the o-ring is there at all (but I suspect someone will tell me!) so, of the two, this is the guy to worry about.

Given that the oil is coming out of the center of the hub, I'd suspect the gasket. Be sure the mating surfaces are smooth, clean, unscratched, and flat. (Check flatness with a steel ruler.) If it were coming out the back, probably the oil seal. Still, I'd replace all three.

 

[Hap Waldrop]

Leaking hubs on a race car is always a problem, here's my advice since I done it what seems like a thousands times with diff gearing changes and all. Clean everyhtin really good, use a solvent like brake clean, repalce the o-ring use Black RTV, you use the gasket if you want but we don't use them on the race cars just the o-ring and black RTV. Make sure you bolt a wheel back on to give everything a good 360 degree seal and let it all set 24 hours if you can for the silicone to cure before you refill the rear end with dope. If you pull the hub and replace the seat there, make sure you clean the housing thread for the hub nut with solvent, air blow dry, clean the nut the same way, use red lock lite and torque to the factory torque, 140 ft. pounds. Remember the left side hub nut is left hand threads and the right side right hand threads.

 

[Trevor Jessie]

Don't all these rear end housings have vents? Would a clogged vent contribute to the leak?

 

[aeronca65t]

I do exactly as Hap says. It is your best bet, but with these cars, it is still no guarantee. I've owned many Spridgets and ALL of them leaked (or at least seeped a bit) onto the rear drums.
Unless you want to re-engineer things, it's a matter of reducing it to a manageable level.
The picture below shows the details of a Spridget rear.
Much of the leakage can be reduced by a new large O-ring (#37). I use "Hylomar" sealant rather than the paper gasket (#35).

 

[Gunner]

Thanks, all
I worked on the blasted thing all weekend when it was sunny and seventy.. now it's freezing cold and I'm old...
I'll order the new seals and O-rings and gaskets and bearings... then replace everything when the weather is suitable.

Gunner

 

[jlaird]

That's a big 10-4 on the cold. North Florida here.
Berrrrrr.

 

[drooartz]

now it's freezing cold and I'm old...

It's freezing cold here, and I'm young. I'm still not working out in the garage. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

 

[healeyboz]

I second that Drew!

 

[JerryB]

When you get everything off the housing, check the seal surface on the housing end.

It should be somewhat pit and rust free. The seal lip has to have a nice smooth surface for the hub seal to ride on.

Next you can get a sealed both side bearing for the hub. That will help limit diff lube from migrating thru the bearing and collecting and overwheming the hub seal. Using the open or sealed bearing, it MUST have a SLIGHT pressure to be put into the hub. If the bearing falls out, there is too much hub wear in the hub bore. When installing the hub seal , pack the inside of the seal lip with chasis grease and a light smear on the seal surface on the housing when installing the hub.

The hub end play is set by the gasket thickness. Use too thick of a gasket and you will have a floppy hub and the hub bore will pound out. The gaskets Moss sells are TOO thick. .010" thick is what you want (make your own). As Hap sez , I also just use the o-ring with Hylomar tho, and no gasket. But we use double bearing hubs and set the end play elsewhere (at least I do). Another trick I do is to use selective diameter (thickness fit) 1" i.d. o-rings slid over the axle shaft that barely contacts the i.d. taper on the hub when all is installed. This helps keep the lube in the axle tubes and out of the hubs.

In hard corners the lube runs from the banjo and packs up the tube(s) ...the housing tubes are straight and the lube doesnt drain back to the banjo. Way too much lube gets in the hub pocket. Also dont use synthetic gear lube....it makes a small leak big. 90-140 GL4 or 5 for a street car .

Do the drill on the hubs and you will be leak free.