PTO Removal and Installation

[Phil]

Hi, Don,

I used a wheel puller to remove the pulley from the PTO on the new A4 I picked up to harvest its FW cooling system for use on My Ranger. The PTO itself appears to be held to the shaft with 2 Allen screws. Now, it was quite a lot of force on the puller for almost the entire removal process and it occurred to me that putting the pulley back on to the PTO might be problematic as it can't be pressed on while installed on the engine and it can't be installed on the PTO with it off the engine.

What am I missing? Or, can it simply be hammered onto the installed PTO?

TIA
Phil

[Don Moyer]

Phil,

As nearly as I can tell, you're referring to a PTO shaft made by the "Sen-Dure" company. I never liked this style of PTO very much. They were either a bit on the loose side, which meant that the two set screws would not be sufficient to keep the shaft from developing a wobble or the shaft fit so tightly that it was extremely difficult to remove as during a rebuilding operation.

Some (but not all) of these shafts had 3/8" coarse threads down the center which were intended to be used to press them off of the crankshaft. You simply threaded a long bolt in until it pressed against the front of the crankshaft to back off the PTO. This system had less than a 20% chance of success, and we ended up actually grinding many of these shafts off the crank.

All that being said, if all you want to do is reinstall the pulley, you should be able to clean the PTO itself with Emory paper until the pulley slips on with a reasonable amount of effort. The keyway and set screw were usually very effective in securing the pulley.

If your goal is to use the rest of the fresh water cooling system, you're far better off to consider a PTO assembly as shown in our online catalog. Your pulley should be transferable since the Sen-Dure shaft used a 1" pulley just as the one in our catalog does.

Don

[Phil]

Thanks, Don,

Yep, it is Sen-Dure system and your description is spot on. Since this will become my shed engine I think I will buy your PTO and save myself some grief.

Here's another curiosity. The Jabsco raw water pump has a thermocouple on the back side covered by a rubber pad with two electrical leads coming out. The PO never knew what it was for and never hooked anything up to it. Have you ever seen that and know what it is used for?

[jhwelch]

I would make a guess that that thermocouple used to go to a
device that indicated ocean water temperature.

A few years ago I did something similar with an indoor/outdoor
car thermometer, mounting the outdoor sensor to the ocean intake
thru-hull.

-jonathan

[Don Moyer]

Phil,

Sorry, I'm drawing a complete blank on the thermocouple.

Don