My transmission doesn't seem to be functioning properly. From a stop everything is fine. It shifts perfectly with no slipping or rough shifting.

The problem send to be in OD. AT highway speeds no matter what it will not keep up speed to stay in od. According to the tach I am down shifting from od at about 1800-1900. Fluid is at level and Trans was serviced last year with Lucas added. 78k mi on the original Trans. Thanks fire the help.

 

My bet is trans is fine.

I had stock 95 302 with 3.08 and auto trans. On the highway at 75 to 80 it would not hold od. New heads, cam and 3.31 gears fixed it. It was just too underpowered to hold 80 mph at 1800 rpm.

 

Yep! Ford did some strange gear ratios in hopes of getting better fuel economy numbers.

IMO every truck that came from the factory with 3.55s should have came with 3.73s.

 

Sd Martin, what heads and cam did you use or world you recommend? I tend to think you are correct about being under powered. Thanks

 

why not look at your door jamb sticker and see what your axle code is so we can tell you what gears ya got. iv never heard of this issue because you had to high of gears, but its nice to know i guess.

 

Axle code is H9 which is 3:55 ls

 

eh i dont know, i got the same gears and have no issues, ill leave it to the others.

 

Thanks f150cam for attempting.

 

Drop fluid again and get that garbage Lucas out..

 

Is Lucas not good for transmission? In use it regularly in the fuel tank