I finally got my Cat 963 tore down. It was losing hydro fluid into the drive gear case and the flywheel housing. According to the book, that short splined drive shaft should "press" into the renoveable 4 bolt hub on the flywheel. Mine is a sloppy fit but doesn't appear to be worn. Is there new style hubs and shafts? My shaft has 2 seals on the spline end that goes into the hydro and 1 seal on the end in the flywheel hub. Is this the most probable place for my oil leak? Should i pull the gear case off of the hydro and put bearings and seals in it also? Lastly.....WHERE CAN I GET DECENT NEW PARTS OTHER THAN MY LOCAL CAT DEALER lol? The 2 pieces that "I" think I need will run about $1500. Rediculous! I need help some help here guys. Thanks! P.S. It's a #21Z04421
If you think the biggest problem is oil getting into the flywheel housing, change the one large and two small yellow orings and put it back together. Use a good solvent and wash all the oil out from behind the flywheel, wash out the starter nose too. Later Bob
But what about the press fit deal? Is the spline shaft with the 3 seals actually suppose to press into the hub? Or is mine worn- doesn't appear to be. I had more questions in my original post. Please try to answer them. I don't really want to have to pull this thing apart again lol. Thanks.
No they just need the seal lubed and then it will press in and you lock it with the snapring. The seals are there so the splines can be lubed with HPCU oil. How full was the drive gear case? If it was very full you may be in to a fairly expensive fix. If it is leaking the center gear bearing may be on the way out. They take all of the load and some times let go, at worst the cup beats the bore out and some repair to the casting is needed. That requires an expensive tear down. Hope you can just swap the cups and cones and get going again. This isn't what you want to hear but it's a job for PROFESIONALS/Cat Dealers that know what they are doing. They can cause enough problems you don't need amatures working on it. Later Bob
There is just a little end play with the shaft sticking out of the gear case. Not extreme but if it isn't a bad job to pull the gearcase off the hydro and replace the bearings and cups, I'd rather do it now while i have it on the floor. My gear case had quite a bit of oil in in but i thought it could be coming back out of the flywheel housing. You know, oil goes into the splines and leaked into the flywheel housing and then got churnned back into the gearcase through the shaft seal that was meant to keep oil in the gear case. Make any sense? Is it that big of job to just swap bearings? Thanks.
Lay the HPCU on it's back, mounting surface up with the drive gear case drained. Unbolt the case and lift it off. Check things out, not sure but think you might be able to change the rear bearing cup with out touching the two big gears. I have a pair of tire irons from Mac Tools that will heel out bearings in blind holes. If you caught it before the bore is dammaged you are very lucky. The bearing has a few thou free load(end play) when set up new. You use a LocTite gasket maker to seal the surfaces at assembley. Good luck with it. Later Bob
OK, I got a weird question. Is it posible that I have a shaft for a 973 and a hub for a 963??????? There is no way that my shaft will or would have had ANY press fit about it. I do have a double seal shaft( which is an update) but the part number on my shaft isn't jiving with the part number that my machine calls for. I haven't went to Cat and checked into this farther yet but will this morning. I just thought I'd keep you updated and get your imputs. I truley apreciate any knowlege that you can share.
Sorry if I missled you, the splines will slide in and out by hand. The only resistance that requires any pressure is to compress the yellow o rings. Many people only change the two small o rings, don't know about the large one and still have a big leak when finisshed. Later Bob
It wasn't you that is mis-leading me, it's the tech manual. It says and shows "pressing" the shaft in and out of the hub. My shaft goes in and out of the hub with ease. I haven't installed the new orings yet and that will probably make it go together a little harder but I don't think that I'll need a press. I basically want to make sure that I in fact have the right 2 pieces- hub and shaft. I can't find a part number on my hub but my shaft is double sealed and its part number says it's for a later serial number 963. I'm just wondering if the shaft I have is too small for my hub? Stupider things have happened lol. Thanks.
Your parts are right. The double oring shaft came out later and is interchangable. I think the hub and shaft for the 63 and 73 are the same, not sure about the 43 and 53, they use the 3204 engine and bigger machines the 3304 & 6. You don't need to take the hub out of the flywheel, I just take the snap ring out and get shaft out to change the oring .One thing you can use a press for it changing the seal at the back plate if it has one. Some have a seal some don't, I never bother with it the big yellow one leaks the most and many over look it. Later Bob
Ok, thank you. I'm starting to feel a little better about my ordeal. I understand the back plate in the hub assembly. I didn't see any reason to take that plug out either. One more strange thing about my hub is that it has a snap ring that sorta holds the plug in the hub (like a safety deal). Of course there is the snap ring in the front of the hub holding the shaft in the hub, but mine also has one in the rear(engine end) of the hub. No parts manuals or tech manuals show this snap ring--weird. Well thanks again and if i run into any more problems, I'll write you. Is there anything else I should do to this hydro while it's convienantly out of the loader lol???
Look for any spots the dirt is washed off on the front. That indicates an oil leak. Reseal any leaks tat are not too hard while you can see them. Be carefull of O Ring thickness the seals for the plugs are thinner than the ones for the hoses and lines. Heavy pressure(drive hoses) use square rings. Guess you know that. Use sae10 Hyd oil in the HPCU any oil in the drive gear case but it only takes a gallon. Later Bob