1939 Ford rear axle - how bad is it?

[BillW810]

I bought a non running project off the HAMB. Good body lots of new parts,. I have the car on jack stands. With the car in gear I can turn the rear wheels by hand. I took the speedo turtle off and of course the drive shaft doesn't move, in or out of gear. So I removed the fill plug from the rear housing. This is what I saw:

Trans Neutral:

Move wheel - the other wheel does not move
The ring gear turns - ring gear appears to be ok hard to see with oil

In any gear:

Turn wheel - the other wheel turns in the opposte direction
The ring gear does not move - if I rock wheel a very small amount the ring gear
will rock a little and stop in either direction, like taking up slack

I know I have to drop the rear just wondering how bad it might be.

Anyone rebuild these rears near Allentown PA? Can any diff rebuilder handle this or are they pretty easy. I looked at Van Pelt it doesn't look too bad.

Thanks,

Bill

[Mart]

Sounds right to me.

In gear the driveshaft will not move.

Turning one wheel will turn the opposite one the other way.

If in neutral, with one wheel chocked, turning the other wheel will turn the driveshaft.

Mart.

[BillW810]

Originally Posted by Mart

Sounds right to me.

In gear the driveshaft will not move.

Turning one wheel will turn the opposite one the other way.

If in neutral, with one wheel chocked, turning the other wheel will turn the driveshaft.

Mart.

Thanks I guess I thought too much and just panicked. I'll try holding the other wheel. Maybe I am more overhead than I thought��

Bill

[JM 35 Sedan]

That's why it's called a differential. This allows you to make turns, one rear wheel remains stationary while the other is still driving to complete the turn. Probably nothing wrong with that rear, although you may want to tear it down to check gear wear, bearings, and seals.

[ford38v8]

Originally Posted by JM 35 Sedan

That's why it's called a differential. This allows you to make turns, one rear wheel remains stationary while the other is still driving to complete the turn. Probably nothing wrong with that rear, although you may want to tear it down to check gear wear and bearings.

John, I wouldn't advise tearing it down just to inspect condition. Now, if it showed symptoms such as a growling or clunking noise, that would warrant a teardown!

[BillW810]

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Originally Posted by ford38v8

John, I wouldn't advise tearing it down just to inspect condition. Now, if it showed symptoms such as a growling or clunking noise, that would warrant a teardown!

Turning by hand no noises. The rear externaly looks good. Fresh paint, new zerks fittings on torque tube.

I guess the pessimist in me was looking for problems.

I may not know but I can learn!

Bill

[BillW810]

Originally Posted by JM 35 Sedan

That's why it's called a differential. This allows you to make turns, one rear wheel remains stationary while the other is still driving to complete the turn. Probably nothing wrong with that rear, although you may want to tear it down to check gear wear and bearings.

That I understand I just thought in neutral the drive shaft would turn. My brother had a '55 Chev with a "locked" rear in the early '60s. I remember hopping around corners. I'll learn.

Thanks,

Bill

[Ggmac]

I strongly suggest buying a Motor manual or a chiton manual from the time of your ride . It will prevent more grey hair or the occasional heart attack . They are cheap , less than $20 at the auto flea markets .

[19Fordy]

Bill, Do some research before you even think about taking the rear apart. It's a lot of work. It might be in better shape than you think. There was a big write up on HAMB or Fordbarn a while back on how to rebuild the rear. Get vehicle running and then see how it performs.

[Cecil/WV]

I wouldn't do a thing until I drove it, based on what you have shown!

[BillW810]

I am pretty sure the rear is fine. I had my wife turn a wheel while I turned the other. In neutral the drive shaft turned fine. No noise from anywhere. Thanks for all the responses. I have a manual on order.

[Charlie Stephens]

I would install a set of safety clips or safety hubs and run it. Good advice in general but even better if you don't know the condition of the axles.

Charlie Stephens

[Tinker]

The old posi trac hop on corners!



When you get to that point, rear safety clips for the drum brakes are easy to install on juice rears. very good idea.

[Flathead Fever]

If the gear oil looks good I would not tear it a apart. If its quiet going down the road I definitely would not tear it a part. Unless an axle seal is leaking I would not tear it a part. But if you do, be aware that the paper gaskets between the axle housings and center section are what is used to set the side bearing preload and the ring gear's back lash. Those are your shims. There are no metal shims like on modern rearends. The paper gaskets come in different thicknesses in a gasket kit. Make sure to take a micrometer and measure the thickness of the old paper gaskets on each side. Don't mix then up.

[cas3]

alot depends on what the op intends to do with the car. wanna take the wife and kids to disneyland? better to rebuild it now and not have a failure out on the road. gonna just drive around local and have some fun? drive it for a while-see what ya got

[Tinker]

being this is a bare project, i'd move on to getting it running and on the road.... rebuilt is usually the best.

[JSeery]

Attempting to rebuild a working rear axle without any experience seems like a bad idea to me.

[ford38v8]

Originally Posted by JSeery

Attempting to rebuild a working rear axle without any experience seems like a bad idea to me.

We were all there at some point.
Probably most of us as kids with advice from the local junk yard operator.
Those were the days! Don't we wish those greasers were still with us today!

[BillW810]

The gear oil looks clean. It looks very clean outside new paint, zerks fittings wire through the bolt heads at the banjo. No noise when I turn the wheels. I am going to risk it and get the car running.

Thanks for all the help

[cas3]

good for you!!! i am usually not so lucky, but i buy alot of cheap auction junk, which is usually junk. drive the heck out of it!

[Mike in AZ]

Welcome to the ‘Barn. Sounds like you’re having fun already. Glad you’re asking questions and getting advice. Get ‘er runnin and have fun. Mike