Toyota Repair: 96 V6 3.4 T100 SR5 4WD A/T- Shift Solenoid, landscape boulders, empty trailer


Question
QUESTION: -I have enjoyed driving this T100 for the past 10 years.  Only issue has been front brakes, but that was an easy cure.  Prior to this '96 T100, I owned an '86 4Runner, '84 22R 4WD Pickup '82 22R Pickup, and '79 20R Pickup.  I have owned nothing other than Toyotas, and None has ever left me on the side of the road.      

-My current T100 (with 120k miles on the odo), while towing a 3000 lb total load weight utility trailer, the CEL came on.  After unloading the trailer, I managed to make it back home safely.  However, the transmission is not properly upshifting.  This malfunction occurs around 35-40 mph, so I assume it is lagging shifts from 2nd to 3rd.  If I feather the throttle at that point, it will go up to the next gear best matched for the speed.  No harsh clunkiness or anything like that.  

- I have driven it twice since the CEL came on last week.  One trip to Advance Auto to get an error code reading.  I am 95% sure the test reading was "Shift Solenoid B - Electrical".  The transmission shifted perfectly normal during the 15 mile round trip to and from Advance Auto while pulling no trailer.   Although the CEL is still on, a few days later I needed to go pick up some bails of straw for the garden.  This was another 15 mile round trip, however I was pulling an unloaded utility trailer on this trip.  No shift issues pulling the empty trailer.  After loading 15 bails of straw, the shift deficiency reappeared.  Feathering the throttle  managed to get it to upshift to the appropriate gear for the remainder of the trip back home.  It currently sits in the garage only being used when absolutely necessary.  All fluid levels seem fine, with the exception of a high level on the ATF dipstick.  The truck is parked in a concrete floored garage, and has shown no drips or leaks anywhere or any time during ownership.  It was only driven 2500 miles within the past 15 months.  Admittedly, I have towed some heavy loads of landscape boulders, and have not changed the ATF fluid in a few years.   

- I understand the shift solenoids are located above the pan.  Once the pan is removed, I have no clue which shift solenoid is B, or how to remove them. If you would be so kind as to share with me the location of solenoid B, should I simply change out that solenoid?  is there anything else to consider prior to changing the solenoid?  

-I really would like to drive this truck another 50k+ miles, but will not keep it if proves to be unreliable.

-Any and all advice will be greatly appreciated.

Thank you!

Joe

ANSWER: Can you give me an email address I can then send some info to you that may help.

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QUESTION: "ANSWER: Can you give me an email address I can then send some info to you that may help."

No offense, but my email is listed along with my first name when I posted the question.  I am thinking any legitimate responder should be able to access it through this forum.  I certainly appreciate all info and advice, but unsure who is requesting my email addy here.  Please forgive my oversight if it is a common practice to post a personal email address out here in public.  If it is safe, post yours, and I will contact you directly with mine.  Thank you.

Answer
Your email address is not visible to me if you include it with your name when asking a question that's why I requested it,I can only see it if it's put into the text of the question, you can reply directly to me at <tedrttr@yahoo.com> once I post this answer it will no longer be on my list so please briefly restate the question in your reply.