Jabsco pulley play

[Bill McBoaty]

My salt water pump is an old ITT Fluid Handling (Jabsco) 4900 7 pump. It works well but I’m concerned about play at the pulley where the pulley can be moved in and out by about 1cm. The bearings seem to be fine as is the impeller, gasket, and endplate. I wonder if the pump is designed to have this play or if I’ve missed something in rebuilding it. The pump is off of a 1977 Moody 33 fitted with original Thorneycroft T90. Any pointers would be much appreciated.

 

[rogerthebodger]

Do you have a picture of the pump and pully on the shaft

Different pullies and pumps have different fittings

 

[Bill McBoaty]

Thanks Roger for replying. This is the pump. I bought the boat earlier this year and the pump was working well and looks like it has been well maintained, but I could be mistaken!

 

[Plum]

Thanks Roger for replying. This is the pump. I bought the boat earlier this year and the pump was working well and looks like it has been well maintained, but I could be mistaken!

From what i can see from the parts list, there is nothing that stops the shaft floating so appears to just be a case of fixing the pulley at the correct place along the shaft so the belt, with the engine running, holds the shaft in a specific axial position. Pushing and pulling the shaft by hand tells you nothing other than the gland nut is not too tight.

 

[Bill McBoaty]

Thanks, Roger. That is the way it has been operating and I will reinstall and keep an eye on it. Best wishes, Bill.

 

[rogerthebodger]

Bill the boss on the outer side of the pully should have a grub screw which is used to locate the pully axical on the shaft and to allow for the pully to drive the shaft of the pump.

Either the grub screw has fallen out or come loose. f there is no grub screw hole you will need to drill and tap a threaded hole and fit a grub screw to tighten on to the shaft

It may also all location to dimple the shaft for the grub screw to locate into and to add drive.

A pic of the front of the pully may show the fitting better

 

[billskip]

Bill the boss on the outer side of the pully should have a grub screw which is used to locate the pully axical on the shaft and to allow for the pully to drive the shaft of the pump.

I think he means the shaft is moving laterally not the pully on the shaft...but I could be wrong.....

 

[rogerthebodger]

I think he means the shaft is moving laterally not the pully on the shaft...but I could be wrong.....

Yes I got that but a grub screw through the outer boss into the shaft will locate the pully laterally on the shaft and also provide drive

 

[billskip]

the pulley can be moved in and out by about 1cm.

If you are referring to the shaft 1cm seems an awful lot of end thrust are you sure there is not a circlip missing?

 

[penberth3]

If you are referring to the shaft 1cm seems an awful lot of end thrust are you sure there is not a circlip missing?

Agreed, there's got to be something wrong. OP hasn't made it clear where the movement is occurring. I can think of three possibilities: pulley loose on the shaft, shaft not secured to pump rotor, pump rotor (with shaft) moving laterally inside the pump casing. None of these should be happening.