3rd member seal

[TX '73]

I have a minor leak at the rear end third member. I got a new gasket and sealer for the 9 inch but I'm wondering what is going to happen when I take the cover off the pumpkin. I've never replaced a seal like this. Should I have a grease/oil bucket handy and do I need to replace whatever oil or grease empties from the pumpkin? I know this an easy job but I just don't know about the fluid part of it.

Thanks in advance for the help!!

 

[Yardape]

Yes do have a catch bucket for the gear oil that will pour out. You must first remove the axles if you did not know this already. One thing I used to do with a Ford 9 inch. Undo the lowest three nuts and using a punch, punch the bolts into the housing and let the oil pour out controlled into a catch bucket. When you have removed everything and started clean-up this really helps because you can be sure to get all the oil out. To re-install the bolts, place them in the holes and put as many washers on it that will fit and tighten the nuts on the bolts, sucking them through the housing a seating them into place. Just the same as installing wheel studs.

 

[Broncoholics]

Are you sure thats where the oil is leaking from? 9" rears do leak there but it could be leaking further up and leaking downwards. Could be a pinion seal which is much easier to replace. Then there's the bad news. The old 9" (banjo housings) are weak and crack on the back side/ passengerside middle of pumpkin at the weld. Look right where the tubes meet the pumpkin on the back side. Look real close for a crack at the weld. If there is a wet spot that high and more to the right like I see in your photos I'd say the housing is cracking. I've seen it too many times. This might not be your problem, just something to look at. It can be fixed if this is the case. You have to weld in inside and out. Then add a gusset across the back side so its reinforced.

So when are the larger tires going on? Nice paint, can you send a side shot?

 

[TX '73]

Oh man - I need to clean that oil up and look closely for the crack, I hope it's not the problem. I'll also check out the pinion for a leak. I've got some nice wagon wheels and tires on this truck but I can't wait to put 33's on it. I just have to come up with the money for new wheels and tires. I hear discount tire does pretty decent package deals but if you have another suggestion I'll try anything. I've even been shopping for nice, used bullet hole rims to accomodate the 33x12.50's but no luck yet. The paints okay, not my choice of color but thanks! These are some pictures I took when I put on the lift.

One more question. If it is the gasket, is it totally necessary to drain all the gear oil and replace it? If not I can let the gravity carry the gear oil in the pumpkin when I roll the axle out and have the gasket side facing up, right? Then replace the gasket and add oil if necessary, and button it back up?

THanks again!

 

[Yardape]

You dont really need to get all of it out, there is a lip, so you will have about an inch or two deep of gear oil, I like to drain more out because when you try to clean the gasket surface the oil constantly finds a way to get on the surface. So I make sure that it wont by draining more. I have never once put a gasket back in, I have done many and never had any leaks, run a bead of ultra copper rtv silicone around the housing, spread it evenly with your finger across the whole mating surface and tighten the bolts.

 

[TX '73]

Yardape, are you saying don't replace the gasket with a new one? Just silicone the surface and put the plate back on?

 

[Yardape]

Thats all I have ever done, And everyone that I know that are into cars/trucks. I can't vouch for any other silicone than ultra copper, I have always used ultra copper and never ever had any leaks. Correct No Gasket.

Thats all I have ever done, And everyone that I know that are into cars/trucks. I can't vouch for any other silicone than ultra copper, I have always used ultra copper and never ever had any leaks. Correct No Gasket.

It is however a bit of a pain to get the silicone off next time you do this, but if you use a drill equipt with a wire wheel you will make short work of the clean-up

 

[Broncoholics]

Sounds like you're gettin yourself into alot of work doing it that way. Plus you want to replace the gear oil, don't try to save it or reuse it.

The only way to rotate the axle upwards so the oil doesn't spill out is to take the rear axle completely off the truck. There's no need for all that work. Yank the axle shafts out 6" each side and then take off most of the lower bolts of the 3rd member and loosen the tops a bit. Get a drain pan under and insert a ***** driver so the 3rd member starts to pull away at the bottom only. This will help control the fluid so it doens't splash out. I've sealed it both ways, it doesn't matter. using sealant is the easiest. If I use a gasket I seal it to one side and keep the gasket dry on the other so I can pull it off without damaging the seal. This will only work a few times until it rips or enough oil soakes into the gasket to start a leak. Let us know how it goes!