Hi All My CAT 323D hydraulics just stopped working. Engine was running fine. Had a look and noticed hydraulic oil and aluminum shavings coming out between the engine and main pump (sbs-120). We split the pump from the engine and saw the coupler destroyed. Thinking the pump is damaged we removed it. Saw the 4 steel bolts of the coupler were broken off and inside aluminum parts tumbling around. The pump could be turned freely, but a little bit though to turn. Took the pump the the workshop and started to strip it. Do not see any shavings inside the pump. The 2 piston parts rotate very easy. Even the small pump behind the main shaft, also moves freely. Some oil is coming out of the oil seal on the shaft on the engine side. So, why did the coupler fail? So far, I don't notice anything wrong. Will strip more on Monday, but would like some feedback on what could have happened. Will add a few pics later. Jaxo
I added some text too.
The couplings don't last the life of the machine. You didn't bother to list a serial number or how many hours. I picked one at random.
This one maybe.? HeavyEquipmentForums
It's a quite new. Not even 200 hours. We replaced it when we installed a recon engine. Sn: CAT0323DVSDC00803
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I see its not flush. Here is a pic of the old one. We installed the new one on the same spot. This one was totally warned out, but still worked. I am wondering why those fat steel bolts just broke off and why are there oil coming out of the oil seal? .
That coupler is installed about 1/2" in from flush if I had to guestimate. If its supposed to be flush for proper engagement then its strength was severely compromised.
The step wear seems odd, too.
Can you send me the specs for mine? The part number is: 162-6210 There is oil pizsing out of the pump at the shaft, which is my big worry. I don't want to replace the coupling and just have it happen again.
I had a look at a few Youtube videos and all of then also have the shaft sticking out. @heymccall could you please me the specs on mine? I did not mention that the bellhousing was more than half filled with oil. Could this be the reason? How about a stuck relief valve?
I have no access to find that one. Perhaps someone else can chime in.
Assemble the flexible coupling group so that the flexible coupling group is flush with the end of the pump shaft before tightening the socket setscrews. Tighten bolts (34A) to a torque of 110 ± 10 N·m (81 ± 7 lb ft). Tighten the bolts that hold coupling insert (35A) to a torque of 320 ± 10 N·m (236 ± 7 lb ft).
also Note: If the coupling is stepped on one end, the stepped end should be installed facing out towards the engine.
If it was hydraulic oil in the bell housing, the pump input shaft seal is compromised, at minimum. I did the input shaft seal on my 321CLCR without disassembly the pump. Also, it is good practice, if not mandatory, to check crankshaft endplay after the pump is bolted back in, to ensure that the coupling group isn't pushing the crankshaft forward, resulting in engine damage.
Hi @pumkinhead , is that the specs for my mashine? Part nr: 162-6210
Thank you.