I have a 305.5D CR that has over an inch of play on the bearing. The "E" models were well known to have bolts that loosened or broke, however, nothing was ever mentioned about the "D" models, but I suspect I have the same issue even though Cat never said anything. With that said, I got my hands on the 305.5E Service Advisory on how to fix the issue and noticed that both models use the exact same swing bearing based on the part number and also use the same washers, however when I look at the "D" schematic for the swing bearing, it has the bolts as part number 8T-4648. When you look at the service advisory for fixing it on the E models, it has a new bolt listed with part number 491-0944. I don't have the service manual for the E model obviously, so I'm wondering if they originally used the 8T-4648 bolts and these new bolts are an upgrade or if the original bolts in the E's were something completely different. I don't want to order the wrong part and also don't want to order the same exact bolts to put back in it if they are the ones that originally couldn't handle the torque being put on em by the swing bearing. Any help or insight would be greatly appreciated!!
Not sure what the difference is but I think I would use the E model bolts and procedure. The bolts have identical specs according to this except for head height.
The only difference is the plating
The one thing I did notice on em is the 8T bolts are fully threaded as where the 491 bolts are partially threaded, which leads me to believe it was done to get a tighter fitment between the bearing and the structure. Initially I thought it might be an issue because the bearing might be threaded, but they use the exact same bearing, so I'm kinda leaning with what you said on using the newer bolts, I can't see a reason why they wouldn't work based on specs. The only other thing I noticed that had me scratching my head is they're both 10.9 class and have the same Ultimate Tensile Strength, so not sure what makes the newer ones better. I'm likely overthinking it and reading too far between the lines though.
I don't know if you have this info already, but if you don't it might be helpful to you. I would say that you could apply it to a D model if both D & E use the same swing bearing and hardware.
Thanks Nige! That's exactly what I was looking for.