New to the forum. Visited many times looking for answers. However, not finding much info on cat oil pans. Bought a 931b (29y00972) several years ago. Overhauled transmission. Runs good except the other day I bent the oil pan when a oak stick got past the belly pan. Now it leaks oil. Thought about welding it but its got alot of brazing on it already. I've got a chance to buy a casted 4n6566 or pressed metal 6n8910. My research shows that the casted oil pan was used early and then discontinued. I'm wondering if anybody on here has any info on the oil pans.
I had to rebuilt the engine in my 86 931B because a root went through the hole for the drain plug and put a hole in the oil pan. It was a stamped steel oil pan and I wasn't the one running it when it happened. A new stamped oil pan was over $700 from Cat about 10 years ago. The shop that did the engine found a used cast iron oil pan for about $350 including shipping if I recall. Way better but they had to cut the bolts for the oil pan shorter because they needed to be an oddball length in between standard length bolts. You may have to check if the pick up tube for the oil pump is the same. Mine was replaced because they said it had a tiny crack. I'm not sure if the 3204 had different oil pans for different applications. I don't think the damage would have happened with the cast oil pan. I made a bolt on plate to get to the drain plug and protected it with short pieces of channel iron welded to the belly pan. You'll need to pull the engine and transmission as a unit to replace the oil pan though. Get the procedure from Cat or maybe a member on here could provide it. Transmission mounts have to be completely removed in order to get it out. When putting back in leave the oil filter off until the engine is bolted back in or you're guaranteed to dent it. I had to pull the engine/trans twice. While it's out get your starter checked over. It's a pain to remove in the machine. The shop that did the engine pulled it the 3rd time.
Thanks Welder Dave for the info. I got the oil pan off already. Just removed the belly pans (front and rear) along with fan guard. Also removed front motor mount to be able to pick up engine enough to slide pan forward. Also kept radiator gp on by putting smaller bolts in where front pan and radiator mount. Several years ago had bell housing leak that ended up being loose bolts behind flywheel that mounted bellhousing to block.(the reason the last man sold it to me) Had to remove engine and also decided to check out tranny. Tough job but it needed to be fixed. This machine runs and operates good and hated to keep putting oil in it. Back to point. I am now waiting for some pics of the oil pans. Now I know that both will work its really up to the condition of them. Bill