I made a post about this car back in June but the car was at my son'* and I hadn't seen it yet so I had some wrong info. I went and got the car the other day and drove it to my house. First off it'* 2000 Park Avenue SC with a 2003 LeSabre transmission in it. The car seemed weak in every gear, like it would slip some but would move, kind of like a slipping clutch. I was able to get it backed up but it wouldn't make it up a medium sized hill so I took a chance and took the highway to my house since it was only a few miles. I was able to get it up to 60 mph by backing off of the throttle then hitting it again until it would start to slip. It actually shifted decently smooth, it just didn't transfer enough power to the wheels just like a bad clutch in a stick shift. The history on this car... it started not going all the way into park and getting jammed up if you accidentally shifted down into 3 or 2. If you stopped at D it was ok. When it did get stuck he would have to pry really hard on the lever that hooks to the range sensor/switch inside the transmission to push it back out of 3rd. They kept driving it like that then one day it started slipping like I described and the check engine light came on and the code for the input speed sensor came up. My question is, can the input speed sensor cause it to slip like that or is the tranny just shot? They bought a new range selector/neurtral safety switch or whatever it'* called and just for grins I was going to pull the cover off the tranny and replace that and try to replace the filter and fluid before giving up on the car. If the ISS also under that cover or is it accessible from outside of the transmission? Any advice would be appreciated, he can't afford to take it to a shop and the shops around here aren't capable of more than an oil change.
thanks

For reference, the other thread is here: https://www.gmforum.com/buick-172/20...-issues-315346

Amazed this combination worked. I think 2003 was the first year of the next revision of that transaxle. Perhaps somebody in its past figured out how to kitbash it until it worked?

All bad signs. Maybe the pump is burned up? Maybe all of the clutches are burned up? Maybe all of the clutches are burned up because the pump is burned up and very little pressure is being applied to the clutch packs? Those are my most likely scenarios. There are many other possibilities for this behavior. It shouldn't ever be driven this way.

I bet it did! If the clutches are burned out and/or barely engaging it would shift very smooth.

It might have been repairable at this point, but was probably already being destroyed by the prying, either directly or indirectly. Never heard of anyone prying on that shift arm more than once.

Voila'! Burned up transaxle! I bet the shaft was bent or damaged, the pistons etc. in the valve body as well, and/or they were driving it around with some between-gears selection all the time and that led to additionl damage.

What was the code?

From what I see here, the transaxle is shot. The speed sensor only reports what it sees, and they seldom just up and go bad in this transaxle. Again, what is the code?

I don't think there will be any giggling with this endeavour. I believe it is near the top of the transaxle near the selector shaft. Not a bottom-pan kind of thing. This transmission is toast anyways from what you describe. I wouldn't bother. The range switch may be related to the cause of the issue, but now the real damage has been done, so fixing that won't help.

I wouldn't bother with this either. Think of it this way: If the filter is fairly clean, then you're not fixing anything. If the filter is plugged up and that caused the issue, then the damage is done and a filter won't undo it. If the filter is plugged up because of the issue, then the transaxle is toast anyways, and a new filter is just something new to plug up. And transmission fluid is expensive!

It'* not under the bottom pan. I can't remember if it is easily accessible under the side pan (after pulling the whole transaxle out of the car or supporting the engine from above and removing the sub frame), but 95% this is not the current issue. In fact, turn on the ignition but don't start the car. Shift 1 click to R. Shift 1 more click to N. Shift one more click to D. Did the dash indication show these correctly? If so, I bet the range switch is not related to the current problem.

My advice: Stop the bleeding now. This is an overhaul issue, not a minor part issue. It might have started as a minor part issue, but now some serious damage has been done.