Have a 553 that I bought new about 2005 with a total of 332 hours on it. I used it this morning to shuttle concrete from the mixer to forms and no problems. Lit it up a few minutes ago, moved it about 100 yards, loaded a bucket of rubble and a racket came from behind. Within a few seconds lost bucket movement and forward and reverse i.e. only the engine runs with the rattling noise. I know nothing about this machine except how to service it and install a new battery; tasks which I've completed several times in the last 14 years. What could be the problem???
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Bobcat 553
- Thread starter ColM
- Start date
As a follow up: pump shaft is not turning with the engine and that is where the noise is coming from. The coupling between engine and pump seems to be a rubberized affair with a lot of end play. Pump shaft seems to be splined beyond where coupling extends to. No sign of any metal shavings which might indicated worn splines. Pump turns easily enough using a flat blade screwdriver to engage exposed splines. Can't believe coupling hub or pump shaft is worn as no sign of any metal shavings or fluid leakage. Ideas???
Ronsii
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I would bet the splines are gone.
Any which way you're probably going to pull the pump... there is a chance the shaft is broke... but it's usually the splines.
Any which way you're probably going to pull the pump... there is a chance the shaft is broke... but it's usually the splines.
Marcus Wyatt
Member
Is there any chance that one could be partially stripped? My 743 recently lost almost all power (not all) with the hydraulics and it's making a loud whining and grinding sound. It did it suddenly, no warning at all. The hyds barely work but still do a little. Tia
Ronsii
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Sounds like the splines are stripped... the more you run it the more damage will happen... so if one side is still serviceable it won't be for long 
Marcus Wyatt
Member
Thank you much, I was hoping that was all it may be. I've only had the old gal a few months and this is the first problem I've had. It's parked, btw. Thanks againSounds like the splines are stripped... the more you run it the more damage will happen... so if one side is still serviceable it won't be for long
Ronsii
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There are other things it could be but the most likely/common thing is the splines going.