On Wed, 30 Nov 2011 18:45:00 -0800 (PST), Paul
wrote:

On Nov 29, 10:21*pm, wrote:
Paul writes:
I have aSearsfrontwheeldrivelawnmower, 21 inch 6.75HP, model #
917376551, that is about 6 years old. Today while mowing, when I
engaged thefrontwheelsby squeezing the lever on the handle, I
heard
something “POP” and then thewheelsfroze up. Thedrivewheelshad
been making a “slipping- as if a gear insidewheelswas slipping and
then re-engaging” noise periodically for the past few months. I took
the plastic cover off thedriveassembly area and the cable from the
handle lever is not broke, it stills seems to move the lever that is
attached to what appears to be a gear box. Bothwheelsarefrozenand
will not turn by hand. I read some of the previous posts in the
forum,
but still getting educated onmowerrepair. Any ideas on further
troubleshooting to see 1) what problem might be 2) is it something I
could repair(reasonably handy) 3) not cost effective to repair 4) or
any other things I failed to think of ? thanks in advance for your
help.

No experience with geardrive, but I'd suspect ground up gears.
Can you detach the gear box or open it?

--
Dan Espen

Turns out the belt was off the drive shaft that blade is on. Got it
back on and all fine. thanks to all.

If your transmission is like several I have seen, there is a plastic
plug in the top that will allow a couple of thimblefuls of a good
lithium grease to be added which should alleviate the common freezeups
with this device.
--
Mr.E