(ET) Front lift motor experiments... LONG

[John G <zoo_keeper_johng yahoo com>]

Today was the day to get my front lift motor functioning
properly.

After talking with Keith for a while, my 3.5 yr old son and I
set off to find out exactly what was involved.

History.  The original front lift motor would barely lift the
deck off the ground even in "double tension" with the springs in
full use (no links), and it basically would not lift it in
single tension.  Unfortuneately, I did not have the presence of
mind to record the amperage draw of the old motor before I
removed it.

We set off to remove the motor, procedures follow:
a) Deck
-disconnect power cord
-remove springs from lift, not deck
-lower deck
-remove lift strap from deck
-remove deck arms from tractor (pull hair pins, push pins into
frame)
-move deck away from tractor far enough so you have an 8 ft.
radius of clear space at the front

b) Lift motor
-from under the tractor's front bumper, loosen the four outer
nuts but don't remove them
-pull the lift strap thru the fron bumper
-loosen and remove the four nuts securing the lift motor brkt to
the bumper (carefully, it's heavy!!) and pull it rearward and
down (you may need to push the bumper ahead or even remove it
depending on clearance)
-the motor wires (three) will come down about 6" allowing enough
room for you to remove them.  The contacts are an upside down
"U" shape: |-|, clockwise from left is: Red, Blue, Yellow, so
facing the tractor, motor in operating orientation: Red on left,
Blue on top, Yello on Right.  Remove them.
-The motor is free and it can be placed on a bench for
inspection

I had searched this site earlier, and the P/N forthe motor was
listed as a Delcl #5045665, the motor I removed was Delco
#5045631, and no results were returned with a google for that
number.  The replacement motor (scavenged from a rear lift) had
the exact same number on it.  Recall, this is a later production
E-12 tractor.  We found our motor to be in basically good clean
condition, with no evidence of burned terminals, or excessive
corrosion.  The lower uncoated part of the gearcase did exibit
some corrosion, but nothing significant.  I re-installed the old
motor without the bracket and performed some voltage and
amperage tests (24V).  It drew about 6A unloaded, and peaked at
13A when you switched directions abruptly.  The motor sounded
much better off the bracket and tractor than it ever did
attached.

I installed the "new" motor onto the bracket, and the old into
the rear lift.  The rear lift still works even with the old
motor, so I was worried all this effort had been wasted.  I
completed the installation of the new motor and bracket onto the
tractor, replaced the deck and set out to test the results.  I
was thrilled when the deck moved well and quickly with NO help
from the springs, and the lift strap in SINGLE tension!  I
performed some data collection for the group after everything
was hooked up again.

This data is on fully charged batteries (36Vdc nominal) that
have been sitting for over 10 days fully charged.  The motor is
wired for 24Vdc (the old motor would NOT lift on 18 at all), and
I had forgotton I changed the voltage before I made my tests. 
Since the motor does not get even warm after lifing and dropping
the deck 10 times, I feel I'm safe.

New motor, 24Vdc, fully charged batteries (charger off), measure
with an automotive clamp-on ammeter.
- No-load: 7A
- Dbl tension, lifting 150# (me): 13A
- Sngl Tension, deck, no springs: 16A (20 stall)
-  "      "       "  , springs on full: 14A
- Dbl tension, deck, no springs: 12A (16A stall)
-  "      "      " , springs on full: 10A (14A stall)

Now, onto the good stuff I found on lift motors.

The folks at www.a1electric.com have a very good selection of
NEW motors.  They are not cheap at around $135, but I have found
them nowhere cheaper, and up to $472 EA!!!!!

These motors WERE used in GM products as window lift motors from
the early '50s thru 1978.

They (#5045665) were primarily LEFT side window motors except
for most CHEVY cars where they were RIGHT side motors.  The
exceptions for CHEVY: Corvette = L, BelAir/Biscayne = L, Caprice
2Dr = L, all else were RIGHT.  They are the most common motor
found in GM CARS from 1956-1978 (all models).  If you are
searching recyclers for used ones, I suggest non-chevy cars from
'65-'75 and the LEFT REAR of 4 door models is the best source.

I hope this long post will help others.

=====
John G, '73 E12


                
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