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I had my '46 transmission rebuilt with NOS parts to fix a syncro problem for 2nd and 3rd gears. It still grinds every time you shift unless you shift gears at less than 15 mph, and even then you get the occasional 'grind'. My mechanic is getting frustrated and I need any insight you can give me. I don't want to double-clutch for the rest of my life. Thanks.

How much free play in the clutch pedal and are you sure the clutch is fully disengaging? What weight gear oil in the transmission? Do you have confidence that the person installing the new sychros did the job properly?

Where did you get the synchros? They are very rare and hard to come by.Since Packard manufactured their own trans, you have to get their synchros.

I have 90wt gear oil presently, although we tried a heavier viscosity that made it worse and 50wt motor oil to see if that helped, but, it didn't. I asked him about the clutch fully releasing and he said it was. As for the shop, they are reputable and specialize in drivelines. They have been around since the 70's. Dan's Driveline in Las Vegas.

I bought the syncros from Max Merritt Packard Supply.

It should be better, not worse with heavier gear oil so I don't understand that observation. Packard's recommedations were probably SAE90 in the winter and SAE140 in the summer. I'd check myself to make sure the clutch is fully disengaging - with the engine idling and the car in neutral, depress the clutch pedal fully to the toe board, pause 5 seconds, and put it into any gear. If the grinds, the clutch is not fully disengaging.

G'day vegas4al,
to PackardInfo.

Can't offer anything more, instead invite you to include your '46 Packard in the Packard Owner's Registry here on PackardInfo!

vegas4al, I don't know which model Clipper you have or whether it is equipped with overdrive. The car in overdrive mode should make for easy and quiet gear changing as it freewheels. I had a crunching gear change from 2nd to high in my 47 Custom Clipper. It was less with the OD engaged, but would still make a noise although not as bad. My clutch was operating correctly, fully releasing and smooth. I was using 85W-140 gear oil. Along the way I noticed that the rubber bushings on the transmission's anti chatter rod were in bad shape. I installed new ones and wah la - the shifting problem mostly went away. I don't know how to explain this, but it is MUCH better. Something to consider.

(o{}o)

Vegas,
Please keep us posted on your problem. I have exactly the same problem. I have had the clutch adjusted, and will perform the test Owen suggests as soon as I get the Clipper back together and off the blocks. Good Luck.
Mark

These synchro problems are relatively new as years ago the biggest problem was the rotten column shift.

That snubber story is really neat. Unfortunately the Packard manual has virtually no troubleshooting items.

I stopped changing transmission oil because of shifting problems cropping up with the new oil. I never had a shift problem crop up after a clutch job so the problem is most likely internal.

End play should not be a problem because the spec can be set using shim stock rather than selective snap rings. This applies to OD transmissions only.

Obviously I don't have one here and analysis is beyond the typical flat rate trans shop job. Where I would start is to take those synchros to the bench and do the standard palm test for synchros using different oils.

If a new snynchro doesn't pass then the gears themselves may be wearing out.