'94 Tbird LX V8: 4r70w "Headache" tranny

Re: '94 Tbird LX V8: 4r70w "Headache" tranny
'owdy,
I got the 'boid from the mature orig. owner in '97 with 18k mi. on it. No evidence of bad treatment of any kind.
Around 28k mi. I got the shudder when shifting from 3rd to 4th. Had a dealer drain/change tranny fluid and the shudder went away (and hasn't come back). Cost maybe $120.
Around 38k mi. the present malfunction began. At 30-60 mph, it would be just *as if* I'd shifted into neutral. Motor revs up but no power to the wheels. Or sometimes, at hiway speeds, it felt like it had shifted itself down to 3rd or even 2nd gear. Lately it feels like neutral: then I set the - selector- to neutral for a second or 2, then shift to Drive, and it gets back to normal. But it scares po' me ...
Around 48k mi. I had another drain/change using Mercon 5, hoping that would help. It seemed to for a while, but by around 53k mi. it was back to it's old tricks.
It now has 59k mi. on the odometer.
There's a wealth of thoroughly confusing literature on the '94 4r70w? I remember seeing a Tech. Svc. Bulletin that recommended replacement of the trans, the EFI, and the computer. Might as well drive the thang into the river ...
Seriously, I got no $ to speak of, and I'm stuck with the 'boid for the foreseeable future. Surely can't drop it off at the dealer and say "fix it": they'd financially crucify po' me. In a lot of ways (not the tranny) it is a "good car" ...
I have driven the car like it was made of thin glass: to my knowledge it has never had hard usage. All maintenance up-to-date, etc.
Is there any inexpensive way to positively identify the problem with the 4r70w? I'm afraid I've got no money for a "fishing expedition" ...
TIA, Puddin'
****************************************************** *** Puddin' Man PuddingDotMan at GmailDotCom *** ******************************************************;
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what about the manual lever position sensor?
try hooking it up to a computer at auto zone and having the codes read?
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most tranny shops around here will check the codes and drive it for free to diagnos it.

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Go to tccoa.com for some references..
Start with the TSS and its wiring connections, then consider the solenoid assy its wiring and associated grounds... and finally the valve body.
Bet the cruise acts flaky even when it is shifting halfway right
Puddin' Man opined in

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On Thu, 07 Oct 2004 23:53:32 GMT, Pudding snipped-for-privacy@mail.com (Puddin' Man) wrote:

The symptoms you describe may be related to the MLPS, nuetral safety switch or whatever else the may have called it that year. It is the sensor on the driver side of the trans mounted on the selector shaft. It tells the computer what position you have selected. Many of those units collected water over time resulting in enough corrosion to temporarily alter the value seen by the ECM. Since the ECM does not at that time know what you want the trasn to do, it will act a bit wierd. It will not always set a fault code since it is measuring an operator input as opposed to something that should always be the same. For all it knows, you may have selected reverse and reacts as instructed. New sensors usually cost about $30US depending on where you get it. It should come with an updated harness connector and instruction to install. Common sense, common tools and, a way to safely work under the vehicle are mostly all that is needed to replace it.
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Thanks to all for your responses.
wrote:

wrote:
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