1990 Lesabre transmission crossover

how is the fluid level. what is it doing

You have an internal problem within the transmission, check the smell of the fluid, if it is burned then you will need to rebuild or replace your transmission.

The speed sensors will not fix it. This is something that these cars will do in hot weather. The instrument cluster need to be removed and the contacts from the printed circuit to the connector need to be cleaned. Over time they will lose contact and affect the fuel gauge or speedometer. You may have to replace the speedo cluster. Sometimes if you hit the dash just above the fuel gauge it will start working too. Been there done that, fixed mine as the printed circuit was coming apart at the harness connector.

sounds as if you should service the transmission they wil replace oil and filters and gaskets etc ..

i just replaced mine! got them off ebay both for a hundred. its the whole hub,its easy!

Try changing the transmisson fluid and filter and put in a additive for the oil.

yes the transmission is oil is cooled via the radiator and their are two pipes a supply and a return,where they run in relation to the chassis ?? havent a clue because not many to the pound here in spain

i dont know how to get the headlights out in your car but i have done it in my car and the thing that helped me out alot was the repair manual, you can find them at most auto parts stores not only does it help with the headlights but it will help you next time you need to do anything on your car i think i payed $18.00 for mine at kragen

I believe you asked this question a bit differently in another post...???Your best source for this info is a local scrapyard...they generally know what fits what...they have to...it's their business!!! Most common unit in those is either a 440t4 or 125c or their derivitives. Yard will know this!!
Good luck

if transmisson auto check fluid levels ok