Combo box in subform to filter separate subform

Hi,

After much searching thru posts and time spent entering code, I have decided
to ask experts. I have a main form [fManufacturing] with subform 1
[fAssemblySubform] that has a combo box CboPartNumber (bound to PartNumber)
based on query with following:

SELECT tGeneralInfo.JobNumber, tAssemblySubform.PartNumber,
tAssemblySubform.Hours
FROM tGeneralInfo LEFT JOIN tAssemblySubform ON tGeneralInfo.JobNumber =
tAssemblySubform.JobNumber;

On same main form, I have subform 2 in datasheet view
[fAssemblySubformByPartNumber] which is based on query with following:

SELECT tWorkLog.JobNumber, tManufacturingPartNumber.PartNumber,
Sum(DateDiff("n",[StartTime],[StopTime])) AS TotalTime
FROM tWorkLog LEFT JOIN tManufacturingPartNumber ON tWorkLog.PartNumber =
tManufacturingPartNumber.RecordNumber
GROUP BY tWorkLog.JobNumber, tManufacturingPartNumber.PartNumber;

What I want Subform 2 to do is list JobNumber, PartNumber and TotalTime when
there is a match from CboPartNumber in Subform1.

I thought this would be fairly easy - reference the combo box from sub1 in
the query criteria grid of sub2 under PartNumber. Didn't work - subform only
had headings. When I removed criteria and ran the query (not in subform),
all was listed - not able to add, but don't need to - only view. I've tried
requery in the AfterUpdate of sub1 combo box and other combinations, as well,
and can't get this to work.

Sub 2 is linked to the main form by job number - not sure if this matters.
I even tried nesting the sub2 in sub1, but didn't like the results.

Any help to figure this out is greatly appreciated!
Thanks in advance,
Pam