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

My '49 Custom, which I just purchased, exhibits a bit of gear grinding when I shift from first to second, or from third to second. I did the linkage alignment procedure per the page in the tune-up manual, lining up the two levers on the column with the 3/16 pin etc. but it still does it.I know on my '50 Ford doing that alignment did the trick and it shifts seamlessly. Anybody know of anything else I can do, short of a transmission overhaul? Thanks.

Since several have suggested thicker lube for some of the earlier transmissions with clashing issues I would wonder if your gear lube might be old and could stand changing or, due to the high ambient temp you mentioned in your post on fuel issues perhaps it is too thin for the season. Interestingly, some lube charts for the 22-23 series say use 140 gear oil in spring and others say use 90. If you have 90 in there it might be worth a change. Maybe going up in viscosity would work on yours.

Also, you will notice a nice improvement by using a GL-1 rated gear oil rather than the more typically available GL-4 or 5. They are fortified to be extra slippery which foils the synchronizers. You can get a 90 weight GL-1 rated oil at Napa or Tractor Supply.

Thanks for your reply. Well, the owners manual lube chart just says use "90 wt gear oil". I couldn't find any spec for the lubricant in the shop manuals on-line. Come to think of it, I never checked the level, it could be a bit low for all I know.

If you only experience gear clash when going into 2nd on an up- or down-shift, it's likely the 2nd gear synchronizer is worn, because if it were merely an issue with fluid, the shift to 3rd would likely experience some clash as well. However, if you've lived a pure life, you may find changing the fluid will ameliorate the problem.

Straight 90 GL-1 can be hard to find, but NAPA does carry it, albeit occasionally only by special order. Most gear lubed out there are GL-4/GL-5 for Differentials, and many times you'll notice the label will say "GL-4 for axles only, not for manual transmissions" or some similar language.

An acceptable substitute is SAE 40 engine oil -- in fact Borg-Warner specified that as their preferred lube in some of their overdrive transmissions (T85/86).

In newly rebuilt transmissions I've used a synthetic gear live intended for older manual transmissions to hopefully maximize the lifespan of the rebuild. Amsoil has a manual transmission oil that specifies its suitability for older transmissions that is GL-4 rated for transmissions (which means it won't harm the yellow metals in your trans).

If you're experiencing clash, be careful and slow down your shifts-- if the synchronizes aren't doing their job anymore you could end up plutting a knife-edge finish on the gear teeth necessitating gear replacement rather than a more conventional synchro and bearing rebuild.

Good Evening all...One more thing to try while shifting is to double clutch...if the problem is worn Cynchronizers, this should make your shifting easier. Ernie

My 47 Custom was experiencing the same 2nd gear crunching when shifting up to it or down from high. I discovered the clutch anti-chatter rod had bad rubber bushings. I replaced them and the shifting got much better. You may want to check the condition of your rod's bushings.

Also, if your car has overdrive, does it make a difference shifting with the OD engaged?

(o[]o)

When I bought my 47 clipper I thought I had a synchro problem. But, I learned to just shift sooner. No clashes.
I think they were designed this way because ladies did not like to shift. So, engines had lots of torque to permit early shifting of gears...and to take off from second if desired,

Try shifting sooner and see what happens.