If it shuddered, it's probably the overdrive/direct clutch pack that slipped a little. On a 48re, it's the pack in the OD housing with 23 single sided clutch/steel combo disks that is applied by a large 830# spring. This clutch pack cannot slip in forward gears even if it is toast because there is a one-way roller clutch behind it that uses heavy steel rollers on a cam-type ring that 100% prevents slippage.
FYI, the forward clutch is released when the transmission shifts into reverse so there is virtually no probability that the forward clutch pack was causing the shuddering.
The low/reverse band is applied in reverse and there is a chance it was slipping and causing the shuddering. This band is pretty tough and would likely just need readjustment if it was slipping and shuddering. To gain access to low/reverse band adjustment, you have to drop the pan unfortunately.
On my 95' Junker Drag truck, the whole valvebody came loose and caused too low of pressure in reverse to fully engage the low/reverse band and the truck was unable to back up on anything but perfectly flat ground. It took a day or two to figure out what was wrong and by then it had burned off quite a bit of the band's lining but I was still able to readjust it and get many more miles out of it.
One way to test the low/reverse band would be to drive around in manual L on the gear shifter and see if you can detect any slippage.
A way to test the OD/Direct clutch pack would be to drive around in Drive with the OD/OFF and when your in 3rd gear, let off the throttle and see if there is any engine braking. If the truck seems to free wheel, it means the od/direct clutch pack is probably toast. Also take note that when you let off, the torque converter will unlock so don't confuse torque converter release with a lack of engine braking. A lock-up switch really helps with this diagnosis but if you drive carefully, you should be able to let off in 3rd and feel engine braking.
