1025 Brainerd Avenue - Duluth, MN 55811 - Presents
Johnson TD/HD Repair
This page is designed for educational purposes only.


LOWER UNIT IMPELLER/PUMP SERVICE
The HD and TD impellers are located and removed in the same exact manner!

TD-20/HD-25 lower unit has the impeller or water pump located behind the prop in the impeller housing.

Start by removing the prop nut kotter pin.

next remove the prop nut.

Removal of the prop exposes the (in this case rusty and makeshift) shear pin.

remving the shear pin is the next step.

Next, remove the three impeller housing flathead screws.
You may want to use an impact screwdriver to easily break the screws loose.

Separating the housing from the lower unit,

Exposes the water pump or impeller.

Here we see the pump and it's eccentric.

A light touch of sandpaper over the shear pin hole may be required if you want to slide the eccentric off the prop shaft to clean it and the plate behind the eccentric.

The eccentric pin is very small.

and easily lost if dropped after removal.

Next, we remove the plate to clean and buff up before replacing to ensure smooth water pumping.

Water passages and bearing on the lower unit prior to cleaning.
It'snot a necessity to get this far into the lower unit, but I always clean everything thouroughly before reassembling.

Impeller housing and parts.

Inside of the impeller/pump housing looks nice and useable as is.

Backing plate is in decent shape also.

Close up of the water pump before cleaning. these usually are in useable condition.

springy feel to the impeller

as this HD impeller shows, is a perfectly useable impeller.
If the rubber is cracked or very very stiff, it may not work.
Testing the motor with the suspect pump will rule out if it is useable or not.
Though tough to find, the impellers are available in limited supply, so you may just want to replace it if you are this far in anyway.

Eccentric is nice and rust free!

Cleaned up lower unit ready for pump and housing!.
Replacement in reverse order.
pretty easy, and worth the 20 minutes to do to ensure a nice smooth running motor.
Granted this motor was in decent shape upon initial inspection and service, but even a motor with a lot of use cleans up nice, fishing line is usally the worst discovery behind the prop on the prop shaft.
.

BACK TO MAIN INDEX
This website is designed for educational purposes only and is presented free of charge by Big Lures Little Lures, Duluth, MN to better serve the boating industry and make available literature to keep the old "egg beaters" going strong!