Drive Train Leaks

Trying to identify all the drippings coming from the underside of the car   :huh: .

I've started with following drive train leak on my 1973.

How do  I  fix ? Should I fix ?  After I fix . How do I clean up  the drive-train to make it somewhat presentable?

When you say drive train, that means transmission, driveline, and rear axle. I assume you just mean the rear axle, though.

Most likely cause of the leak in the rear axle is the pinion seal. Not a difficult job, just requires a lot of torque to remove the pinion nut and something to hold the yoke to keep it from turning while you're removing and reinstalling the pinion nut. You'll need to install a new crush sleeve behind the yoke and torque the pinion nut to 175 ft-lbs to get the correct preload.

As far as dressing up the axle housing, just depends on how much effort you want to put into it. You can wire brush it and coat it with rust converter and then paint, or just Rustoleum paint. You can also use the Eastwood rust converter primer. Or, you can remove the axle, then remove all of the rust then epoxy primer it and paint it or have it powder coated. POR 15 paint is another option. You'll need to remove the driveshaft when you replace the pinion seal so you can tackle that then.

+1 on what Don said. I would just make sure it is the pinion seal and not the differential housing that is leaking. If in question I would suggest cleaning the area good with a degreaser and then keep an eye on it to see where it is leaking. May take some time to show back up depending how bad the leak is. If it ends up being the differential housing then it becomes a much bigger job. If you have to go down that road then it would also be a good time to replace the axle seals, bearings and have the rear end checked out while you have it pulled.

From the looks of the drip on the floor, I would say it's leaks a fair amount. It look like it's far enough forward to be under the pinion seal, but I agree, check the seal between the carrier and the housing, too.

Don C.

Thanks for clarifying . I meant the Rear Axle that was pictured in the image.

Wasn't quite to sure to call it ' the pumpkin' .

I'll change the subject line, how to do that? 

I'll start out by degreasing the area to locate the true issue per Kilgon.

How do you determine if it's the pinion seal or the diff housing? But clean is needed first .

Any problems with Driving it like this till I get it resolved? 

It's not a daily driver .

Pinion seal is a pretty big job for a novice mechanic. Getting the crush sleeve correct is paramount.

I suggest...removing the entire 3rd member. Take it to a driveshaft/rear end specialty shop. Take your axles with you.

The shop can properly replace the seal, remove and replace your axle bearings, and inspect your differential while it’s out.

While the shop is doing all that, you can remove and replace your axle seals, clean, prep and paint your complete housing. You can then paint your 3rd member when you get it back.

Put it all back together, saving yourself 500 dollars in labor and knowing the job is done right.

Voila! Done.

Another common leak is through the bottom differential studs which would be unrelated to the gasket. Either copper washers and/or black silicone on the threads.

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The pumpkin is the removable carrier that bolts to the front of the axle housing by 10 studs and nuts. The pinion retainer bolts to the front of the removable carrier with five bolts. The pinion seal is inside the front of the pinion retainer behind the driveshaft yoke/flange.

There are four potential sources of leaks, listed in most likely to least likely

1. Pinion seal

2. Carrier to axle housing gasket

3. Pinion retainer to carrier gasket

4. Crack or bad weld in the housing

The pumpkin is the removable carrier that bolts to the front of the axle housing by 10 studs and nuts. The pinion retainer bolts to the front of the removable carrier with five bolts. The pinion seal is inside the front of the pinion retainer behind the driveshaft yoke/flange.

There are four potential sources of leaks, listed in most likely to least likely

1. Pinion seal

2. Carrier to axle housing gasket

3. Pinion retainer to carrier gasket

4. Crack or bad weld in the housing

Click to expand...

Don, I am surprised you didn't mentioned the leak through the stud threads which is also very common and its unrelated to the gasket. At least that was in my case.

I saw your post about yours leaking around the stud, and thought to myself, "Damn, I missed that one".

You had it covered and I wasn't going to go back and edit mine.

Most of the ones I've seen leaking around the pinion seal were due to bearings, but as these cars have gotten older I believe most are now due to wear on the seals or dried out seals due to inactivity. (Hmm, saying inactivity sounds like an ad for Chuck Norris's Total Gym)