Hi,my 2005 monte ls has 137km on it and I noticed it would shift late and you would feel a slight jerk when it did,so i scanned it and came up with the P1811 code,I phoned a reputable transmission shop and he said I needed to have my transmission rebuilt,because the valve body seals are shot??,is this true,I put a bottle of lucas stop slip in and it was fine for a couple of days,now its doing it again,also from what I've read that maybe a transgo 4T65E shift kit might remedy the problem by making it shift faster??

 

i had that code when my trany was going. i lost 4th gear. my gears wore down to nothing. i had other codes as well. and i also only had 122 k on mine. your lucky you got more miles out of yours. start saving up now, and have you trany rebuilt. it took me 7 months to save up. i babied the car to make her last. my cost was a little over $1800. the 4T65E are crappy trany's and kill over too soon.