After 1-1/2 years of tracking down the rumbling noises from my 1952 Chevy pickup and replacing flywheel, clutch parts and transmission, I finally solved the mystery today... Both rear end pinion bearings (part# 3 and 4) disintegrated after they cried for help starting in February 2019... see photos Leaving the ring with missing teeth, while the pinion carved its pattern into the casting along the way. Sadly I was unable to diagnose the problem without the inevitable to happen. I posted a couple of threads along the way. https://www.jalopyjournal.com/forum...r-transmission-noise-only-under-load.1147799/ https://www.jalopyjournal.com/forum...d-transmission-jumps-out-of-3rd-gear.1174941/ Since that last post, we had the worst 24 hour snow dump in my area in decades, on Dec 26 2019. I was stuck for 16 days in 2 feet of snow until I could shovel my way out from the garage to the dirt road, taking 4 full days. The dirt road was wet mud puddles by then and I just barely got out to the paved road slipping and sliding and limiting the RPM revving to what was required to keep momentum and stay barely on the road and hold forward direction rolling the steering wheel wildly in all directions. My dogs were along for the ride next to me on the bench seat as usual and rather uneasy but trusting. Once I reached the paved road, I knew something broke really bad in the drive train - heavy clunking noises and broken metal part sounds. I immediately suspected the transmission broke, however it shifted smoothly in all gears and I decided to drive 20 miles to town regardless, get supplies and head back home, since under load the ride was pretty smooth if I stayed around 30 mph. Another thrilling muddy sliding fun-ride and I was home with my heart pounding out of my chest and adrenaline in my system for the remainder of the day. I couldn't believe I made it with all the noises and especially today after looking at what happened to the rear end. I suspected the useless gear-jumping transmission or maybe the U-joint was what broke, so I left the truck untouched until I found another hopefully working replacement transmission last week. Yesterday I put it in and today opened the rear end cover plate and learned what happened ... see photos. You can see some of the roller and ball bearing parts and the damage to the cast part holding the gears. The drive pinion is moving around loose without the bearings, needless to say. That rear end was professionally upgraded to a brand new set of 3.55 ring & pinion in 2001. I remember the shop said the rear was in bad neglected shape and they had to find a few parts from other donors to get it right. They advised to keep changing the gear lube once a year, which I did. I assume the bearings that now exploded must have been original and they didn't change them. Otherwise I can't explain why this happened. But I am no expert and maybe one of you guys can explain this. My other ride the 48 coupe has a 1954 original torque tube and rear gears, so now I am paranoid that I will go through this again one day. At least I now know the warning noises and sounds to pay attention to and make the proper diagnosis. Anyway, still have to fix this and as far as I can see I have at least three options: - Get another new 3.55 ring & pinion set and bearings and have it replaced by a pro - Get another new 3.55 ring & pinion set and bearings and replace it myself - Find a 1954 truck torque tube with 3.55 gear section in good shape My vote goes for the latter, as the truck only gets about 1000 miles per year these days. What do you think ? Has this happened to you ? What did you do and how did that work out ? Any advice appreciated greatly as always !