Hi I bought an older 5' shredder and it shook a bit but I thought the blades might be out of balance, but later found the stump jumper had been bent about 1/4-1/2". So was wobbling. After finally getting it off I had damaged the oil seal on the bottom. So started disassembling it, to replace the seals. (I had the bottom really hot a couple of times) But now my problem is. The input shaft has a flat plate on it covering the seal and it looks like a couple of fine threads on the outside but no pin holes to remove the plate around covering it. The output gear shaft has no locks or keepers visible. Has anyone had one of these before. I cannot find a brand or name on either one. Yes a know the old fill it with grease trick but I would prefer to have the seals in tack. Thanks in advance for any help.