94 3.8L Bird slips into neutral

Anyone had a problem with auto trans slipping into neutral while traveling at a average speed of about 40 mph? It'll slip into neutral and then back to 2nd and then finish the shift sequence.
This is one of those "doesn't do it all the time" problems. Started out as a warm weather thing and ressolving the problem was a simple as manually shifting through the gears for the first series of shifts and then it was fine until it was shut off. Now its become intermittent in all weather conditions and shifting trough the gears only sometimes resolves.
When I bought the car a few years back used, the dealership replaced a couple of servo's but it only helped for a short period (the winter months when it was less likely to do it anyway).
One thing I did notice, is that is seems less likely to happen with a full tank of gas (maybe I'm just imagining).
I've tried to put some ryhme or reason with this to no avail!

Ricebird

That sounds alot like my 94 4.6 There a post down alittle way.Check it out. I could going about 40 to 50 miles an hour and it acts like it go in to neutal like yours.I keep driving it is.hopeing it will not get any worse.

Thanks, I hoped mine wouldn't get worse as well, but it has. Have you had your transmission scoped yet?
I think this is not a mechanical problem, rather an electrical. Just a hunch due to the fact it doesn't do it all the time. I went to alldata.com and ran the TSB's for this car and there are a few that may apply. The one that most catches my eye is 02-17-6 A/T Inadvertent shift Interlock disabling. There are quite a few on trannys for this year.

You might just need to rebuild your tranny.

My 95 did that and I just replaced the tranny instead of messing with it. I found a Ford rebuilt at the junkyard for $50.

I had it on a scope and no codes showed up ?

Tom

PS Theres no junk yard in my area that even has one, And if you got a Ford tranny from some junk yard for only $50.00 you had have a gun to the owners head.

Another PS.Congrats .thunderbird muscle on your 1000 post.

Tom

It helps to have friends in the salvage business!

Your dealer has a transmission tester that gives them info that you don't get by checking the OBD codes.

97Bird Where do you live ? I would like to get to know your junkyard bubbys..But here in the cold state of Wisconsin A Thunderbird and there parts are hard to come by. What kind of trannys do the F-150s use ,even the newer 2000+ ?

Tom

Well, I did a little reasearch and it led me to the NTSB website where I searched the complaints section on the 94 T-Bird. Funny enough, there are 65 listed complaints of the same problem as mine. Obviously not enough to warrent a recall, but it did lead me to a possible fix. One out of 65 complaints that I read had a final solution listed on it. It was from a guy who had replaced the tranny and still had the problem. He took it to a reputable tranny shop and they found that the Transmission range selector was rather worn. It was not completely engaging into drive and the slightest bump or vib would cause it to skip into neutral and then back again. They replaced it for him and no probs since.
I experimented with this on my way home Friday. I held the shift button in and ever so slightly pulled the shifter back towards drive. Coincidence or not, it didn't happen the whole way home(about 5 miles).
I'm going to crawl under there and adjust the linkage if there is an adjustment or replace the whole thing (about 100 bucks). I guess its a better start than 1500 to 2 grand for a new tranny.

Cheers!