Packard Forum Index » Post-War (1946-54)

I have a NOS differential, complete, that you would be welcome to for shipping and whatever donation to this website you would see fit to make.

One other bit of info:

I haven't noticed any rear end whine or anything. I know in general what that sounds like because I had to replace my Toyota Tacoma differential after 250,000 miles. The Cavalier doesn't make any notable noise, at least from the vantagepoint of the passenger compartment.

Thanks, I just sent you a PM!

Will keep y'all posted.

I don't know if this will be of any help, but I found this in Popular Science, June 1949.
Wes

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Thanks for the thanks but I don't think that the 10 degree lash in your rear axle is the cause of the rough shift from fwd to reverse. It is well below what I have experienced in smooth shifting cars. Also, the rear axle is not affected by warming up and getting looser, it is a pure mechanical connection.

My guess is it's in the trans which can be affected by temperature. Some operating seals in the reverse piston servo are rubber.

good luck.

Just an update:

Planning on:

1) Checking the idle speed. The mechanic who got the thing resuscitated may have set the idle speed a bit high. I am looking for an appropriate Digital Multi-meter with an RPM setting. There are a few out there, I probably will go with the Bosch-Actron CP7677.

2) Complete system flush (and replace transmission pan gasket), replacing with Dextron III. I have been thinking about possibly replacing the low-range and reverse piston seals at the same time. It appears I could do that with the transmission still in the car, but I would need the Packard tool PU-308. Is that available or easy to make?

I think the right thing is to do these two things first, out of due diligence. The transmission otherwise operates well - I am loathe (both from the standpoint of not fixing something that is not broken, and from the $$ standpoint) of trying to get the transmission completely overhauled. Some of the problem may also be the differential, but as Fred says, if it operates satisfactorily when the transmission fluid is cold, it may be something else.

Why the expense? Just grab a screwdriver and turn the idle down. That is only about an 8 second investment of your time. The only difficulty is that on a 4 bbl carb the idle speed screw points straight to the rear right next to the exhaust manifold. Awkward. In fact I usually use a small (1/4"??) open end wrench to turn it.

The fluid change is a good idea as are new servo seals; that saves a lot of pressure loss in the trans. Have never used the Packard tool in the three dozen or so of those trans I have built. The key to not loosing your band struts during this operation is to remove the servo covers and pistons but do not remove the valve body.

On transmission fluid, is it better to use the F type with original bands and the Dextron with the new replacement bands? Or does it matter?

John

I'm using Type F with a recent rebuild by Ross with modern friction surfaces. Although some certainly may prefer a softer shift, I prefer snappier lockup, minimizing slip time. Frankly, in the long run the work quality and comprehensiveness of the rebuild and at least equally importantly the driver's habits no doubt have far more to do with transmission longevity than fluid choice.

So with some experimentation, I was able to get the idle speed set to a point that it's not too slow but the transmission doesn't "clunk". It's still "solid" but not to the point of alarm.

Still working on everything else, of course

Thanks everyone.