As you will note, there was as wide an array of opinions to my problem on the brickboard as there was when enquiring with local mechanics/tranny shops/dealers and independents. This is obviously due to the variability of correct answers depending upon what is going on with the individual car.
 
 

MESSAGE #10054120:  Re: Another Automatic Transmission Saga
     AUTHOR:  Dick in Falls C <saab85900@aol.com>
     DATE:  Friday, 1 December 2000, at 8:45 a.m.
     Response To #10054111:  Another Automatic Transmission Saga
     Author:  michael
     Date:  Friday, 1 December 2000, at 6:34 a.m.

> The ATF fluid is at the right level, and all the people I have seen
> have said that I would just waste money to change it, or that it is
> "not too bad" and have not recommended changing the fluid
> yet. It is brown but smells more like normal ATF than stuff that has
> been toasted.

Step 1 change the fluid. The brown shows that it is at least somewhat
oxidized.
Changing the fluid won't hurt anything, and could solve your problem. And it
is relatively inexpensive if you do it yourself.

Go back and read the discussions on this--particularly the comments by some of
the Volvo techs.
 

Your problem could very well be a sticking solenoid or ball valve which could
perhaps be cured with new fluid. A complete flush costs $20 or less if you do
it yourself or $80 to $100 or so done by a mechanic. Certainly a lot cheaper
than replacing anything else and the obvious place to start.

As others have posted, I have seen many 850/70 series auto trans problems
cured with a fluid change (7 or 8 that I personally know of) - don't bother
putting anything but the best synthetic tranny fluid. This is relatively
cheap, you can do it yourself, and it certainly will not hurt anything. If it
doesn't cure you problem, then you can proceed with more serious
troubleshooting.
 

  > It is brown but smells more like normal ATF than stuff that has been
  > toasted.

  Mine quickly gets (got, twice) (and stays) more brown than red (not dark,
  though). Since mine has (had) no problems, I consider this exceedingly
  normal, and tend to side with those who've seen it and weren't alarmed, and
  not those with a red fetish.

  For every automatic transmission whose behavior has been significantly
  and permanently helped by changing ATF, I'll bet there are at least 3
  that haven't.

  Dexron is already the most over-engineered fluid in your car (unless,
  perhaps, you fill your tires with pure nitrogen?), so I do not find
  synthetic ATF to make economic sense, even though I use synthetic engine
  oil (which sees harsh temperatures and chemical contamination from
  combustion byproducts).

  And as for a "power flush", these ATs pump their own ATF, and can fully
  flush their own with a minimum of equipment, none special.

I would definitely make sure you're putting the transmission into the gear
  selection position as indicated by the shifter (even when warm). The
  part that locks the switch into precise position may be loose. (Of course,
  that could be easily diagnosed by moving the shifter slightly from its
  normal detent position as the problem occurs...) If it's just the gear
  position switch contacts, ramming the shifter back and forth from Park to
  First ought to wipe them clean(er). Maybe that's what the first guy tried,
  but either the position holder was further loosened or else some goo inside
  the switch was spread among the contacts instead of being wiped off.

  There's also a heavy-duty multi-multi-contact connector to the transmission
  that's fairly obvious with the air box removed. It might benefit from a
  few un-/re-connects. Your car's battery hasn't ever burped up anything
  nasty atop the AT, has it...?

  223 = TPS signal too low (bad connection?)
  134 = Incorrect load signal (bad connection?)
  313 = Incorrect signal from gear pos sensor (bad connection?)

  I would expect a Volvo tech to be able to ascertain if the problem is a
  bad switch or sticking solenoids, or at least differentiate between the
  two...

  I would not expect a new gear pos sensor to suddenly provide full/correct
  signals from it and 2 other inputs to the AT.

  Wiggling a large multi-pin connector, OTOH, might.

  Good luck,

  - Dave; '95 854T, 105K mi
 
 

  Most shops nowadays can do the BG power flush service for about $100. Did this
  to both my cars, money well spent. Try refilling with synthetic after flush
  service, most shops will fill with synthetic as part of BG service for
  extra$$.
 

I tried the cheap fixes. None worked. Trans just got worse. Are there enough
of us with low mileage trans failures for a complaint to NHTSA?
I ended up having to replace trans. $2500 parts + labor.
 

  I know two people that auto trans went out at about 40K. They both had to
  replace the transmitions. One took it back to volvo and got them two pay for
  half. I have a 94 850 and if the trans goes I will deffinately bitch up a
  strom at my local dealer and the zone manager. The volvo manual for the 850
  given no interval for changing the trans fluid. Does that mean it is to last
  forever - I don't think so. If changing the fluid does fix the ploblem please
  post it. If it does not I would complain to the zome manager until you get
  some help - it is a $3000 job. If you go to the cartalk section of cars.com,
  you can look up your local zone manager for volvo. Good luck. Guy