Revs to 4000 rpm but wont do more than 20 mph

SOURCE: Sporatic rpm increase at 2000 rpm (increases to 4000 by itself)

change tranny fluid with mercon v also can add friction modifier (ford part# m-19546-a) and be sure to drain torque converter as well. should fix ya

SOURCE: transmission is not shifting properly on my 2000

You could have a bad valvebody in your transmission or a bad pump in your transmission or your clutches are bad. In any case you have a bad transmission. Please rate my answer.

SOURCE: will not accelerate wont even rev past 3500 rpm's

i have a ford fairmont 95 ef that rattles when i accelerate sounds like chains on a bike clunking and wen i put my foot down it wont revv any higher than 3500 rpm and keept jerking about like it was tryna risist going faster and before u ask me yes the car was in drive so it wasnt because i forgot to change gear if any one can help me as to wat the problem might be it would be very much appreciated

SOURCE: i have 2006 scion xb and when driving the rpm

3500 is about normal for an xb at 65 mph. My previous ride was a pickup and rolled at about 2000-2500 on the highway. But the XB's engine is way more "tightly wound". Your rpm gage should run at about half of of your speed...ie: 70 mph will be about 35 (3500) rpm, 80 mph will be about 40 (4000) rpm. Freaked me out when I first got the thing, but after researching it Ive found out that with a stock engine it actually runs more efficient at the higher RPM's. The 06 boxes won't redline until 6000 rpm, so unless you are driving 120 on a frequent basis you're good. You can probably have it modified to run lower, but you will lose the awesome gas mileage and overall it is not going to improve the way it runs, and would have no benefit............

SOURCE: 03 yukon with 125000 miles wont shift into 3rd

yes but you can get it less becauses the kit cost only 72 to220$ for it and its a half day labor onit any ? you can call 863 261 6116 if no answer leave a message