OK, broke the Ranger back in March. Did a few quick checks, didn't see anything simple. I had lost 3rd and 4th gear while passing a coworker about 3 miles before getting to work on a Friday. 4R70W and the first full throttle pass with the new cam. Is pulled great in second and felt a little bump as I lifted/it upshifted (maybe I did, not completly sure). Anyway I was passing and found that I could limp to work in 2nd. Limped it home. Did the diagnostic tree, checked the shift solenoids. They both speced out correctly. Finally did the pressure test on the direct clutch pack. Bad news, it had pressure when it should. Looks like the solenoids and valve body are working right. So I finally pull the trans and tear it down this weekend.
Found some tiny bits of steel (not the normal shavings/fuzz) on the magnet. Also noted lots of brass dust in the oil but other then that the oil looked good. Kept going into it, finally arrived at the stub shaft. It was broke. Small end had twisted off. This is a '98 and up improved factory piece, they are not suppose to break until you put the bottle to them. But it broke on the first full throttle run I did with the new cam. You could see the splines were actually twisted.
Now the debate, what to do. There is actually several parts around the stub shaft that took a beating as well. Still have not found the source of all that brass, but then again I can't even get the sun gear out of the planatery set as the direct clutch hub expanded and swedged in place when the shaft blew inside of it. I have a lead on a few other 4R70W transmissions, but they are all 4WD versions. I would have to tear one down and convert it to 2WD using my old parts and shift kit. With the upgraded stub shaft this time. I guess I will be getting another transmission and rebuilding it. not sure if it will just be my 2WD tailpieces into a 4WD transmission or the 4WD guts into my old case. I guess I should really look for a 4R75W from a 5.4 and take those gears. Might ease up on the direct clutch accumulator as well. I nver thought it hit too hard. I know the intermidiet accumulator needs softening, I keep blowing the tire off on the 1-2 shift. Then there is that lead on a M5R2 from a supercoupe a friend has sitting in his garage not being used for anything.
There's the problem...
Moderator: MalcolmV8