ok I have a 2000 xls 4.L OHV I was doing an oil change and noticed that there was two bolts missing from the transmission pan and a little fluid on the pan so I went and bought the bolts and figured while I was there I would do the filter too I get home get under the truck and all of the 16 bolts where loose I took all of them out buy hand changed the filter cleaned the sludge out of the pan and put it all back together put 4 quarts in and the level was good and took it for a test drive its definitely more responsive and shifts a lot smoother too I have 3 questions
1) how much sludge in the pan is normal for 100 K miles
2) why would it shift smoother if the fluid wasn't low
3) what would cause all of the bolts to loosen and is the a common problem