Tried to swap in a manual 5 speed tranny to my 2000 ranger. With the driveshaft out, I can run the speedo up in excess of 80 and nothing. Put a driveshaft in and by the time it hits 40.... if it were smaller I could use the truck as an **** vibrator. So went and had a brand new custom driveshaft made...and of course, zero change! With all of the previous nightmares with this truck since this past Thanksgiving, I firmly believe this truck is to never be driven again, but rather to just repair this and then on to the next and will never run out of crap to fix. Have a vibration that seems to be on the front end of the driveline, almost like the output shaft for the tranny is perhaps worn where the splines are?. If I stick a driveshaft yoke in it and try to shake it, it just BARELY has an ever so small amount of movement. So next thing is gonna be to crack the tranny open and replace the entire backshaft/gear/bearing set....unless anyone has any other suggestions.

 

OK there is a problem with the first sentence

The 1998-2000 Ranger speedometer signal comes from the rear axle not the transmission, so rear wheels turning forward is the only speed signal available
So can't get speedo to 80mph without a rear driveshaft
Could it be a 2001 Ranger?

With the drive shaft inserted into the rear of trans and trans in gear, can you turn the drive shaft manually?
If so then yes output shaft is damaged

If not then differential is damaged
If its an OPEN differential(most common) then an axle may be bad so all the power goes to that wheel/side because its easiest to turn and no movement
Jack up the rear wheels, trans in Neutral if driveshaft is connected, spin either wheel, the other wheel should spin in the opposite direction(OPEN Differential), then go to the other side and spin, should be the same
If one side doesn't spin the other side then axle is broke or a spider gear
Loosen the rear cover and drain the oil, then remove the cover

 

1). Nah actually it is a 2000. I just know how fast the truck is rolling in 5th gear at a given engine RPM on the tack. And nah I think I found the prob. This manual tranny is out of a 96. And while the speedo sensor is on the tranny, my truck uses the one @ the rear axle as you indicated, so the tranny speeds sensor just isnt used. BUT.....upon tugging the rear tailshaft off for inspection, I happened to notice that there is supposed to be a bushing immediatly behind the rear seal on the tailshaft. The tailshaft housing even has the little steel galley for the oil to travel down to run oil to the rear bushing....cept there is no bushing there!!! lol Its not worn out or anything, its not there at all. LOL. I didnt catch it last time I had the tailshaft off because I made the mistake of presuming that all the parts were there. I checked on an exploded diagram and yup, found one on that pic as well. LOL.