The 49–54 Ultramatics can generally be shifted from low to high at speed as long as you take your foot off the gas when doing it. These Ultramatics had little in the way to limit engine flare on the low to high shift since it's a manual shift. You don't keep the gas pedal floored when shifting from 2nd to 3rd in a manual car, do you? The other possibility is if the shift was mistimed in the other direction, then "something" actually broke from the transmission locking up between the gear switch.
Likely the high range clutch pack is burnt to a crisp and the car became completely undriveable without experiencing severe clutch slippage. Fortunately there are tens if not hundreds of unloved Ultramatics lying around and rebuild kits are readily available.
If you need someone to rebuild it for you, give me a shout. Or if you want to DIY, I would encourage you to post your questions on here, as there's a good amount of small things that can go wrong...
Soon I will begin uploading a video series featuring the venerable Ross Miller how to rebuild a Twin Ultramatic. Yours is the first gen Ultramatic. Different, but also not terribly so. You may want to keep an eye out for that on my YouTube channel,
HPH Packard Lowrey.This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=273506