[Smith1000]

I don't know if it is too late or not at this point, but you might try some additives. Might have to pull some fluid out to make room for it.

I have a '97 Lesabre with 180,000 miles on it. It has the original engine and transmission. I changed the fluid once at about 100,000 (I think). When I changed it, I put in Slick 50 automatic transmission additive. It drips some, so I have to add fluid now and then. Around 150,000 miles, I dumped in 2 bottles of Lucas automatic transmission fluid additive. I tend to supplement with these types of additives. I ran a Ford Taurus up to 160,000+ miles with no transmission problems. The guy who bought it from me drove it for 2 more years before wrecking it. I knew one guy who put 2 transmissions in his Taurus.

Now that I think about it, my 97 Lesabre got kind of low on fluid once since it leaks some and it sort of acted like you are talking about. It would slip or not engage. Hope it works for you eventually.