5000TQ Avant Starting Problems

[Stephen Sherman]

We have an old, trusted (at least until now) 87 Avant turbo wagon that 
still get regular use as a snow car. It has been running well until 
recently, when the temps went below 0F and the starter began having 
problems.

The symptoms are that at cold temps (even with a charged battery) the 
starter will only crank the engine for a few seconds, then it disengages 
from the flywheel. Unfortunately a sec or two is not enough to start the 
engine in these cold conditions. At warmer temps (say above 10F) it 
cranks and starts just fine. The length of time the starter stays 
engaged with the flywheel does down with every attempt, as the battery 
drains.

I have a few questions, before I start crawling around in the snow to 
pull the starter:

1. Since this seems to be battery charge related, what is the chance 
that a new Battery sould solve it (current battery is ~2 years old)? Any 
way to tell short of just getting a new one?

2. I've seen several posts about lubing the starter bendix/solenoid  
mechanism. Seems like it couldn't hurt, but can I do this effectively 
with the starter still installed? Is there a port or bolt hole that will 
allow some WD40 or the like to get where it needs to go, and not end up 
on the flywheel and clutch?  If so, which one is it and where is that 
located?

3. Other suggestions?

TIA