hey guys.. well i got to the point that i don't no whats wrong wit my speedo.. my trucks a 1979 chevy 3/4 tone.. i got a 4 speed trany in there.. standard!.. when i first baught the truck a year ago.. the speedo worked fine.. till one day it bounced around soo much and just gave out...... stays at 0 now.. i changed the speedo in the dash with a good used one.. new cable.... took the little gears apart.. (that little thing the cable goes in before the trany.. all the gears were there.. so i cleaned that up and oiled it nicly.. still nothin.. so i took the cable out.. got my drill out.. hooked it up to the cable.. and she spun at 100 k.. so the cable to speedo connection is good.. then i hook the speedo up to that little gear box thing again.. and again speedo is fine.. put it back in the trany....... nothin works?? i pulled that little shaft with the gear on it outa the trany.. it was fine to.. the gears in the trany are still in there.. they line up nicly and everything.. so whats the problem??? is it external in the trany??? be a big job to fix? thanx

Is the gear on the trans output shaft firmly attached to the shaft?

jimfulco has it right! the gear on the the output shaft has come loose. I had this problem on my 69 vette. It's a plastic gear with a metal retaining clip, & that has probably pop off. Pulling a 4 spd. out of a vette is a major pain, & I didn't want this to happen again. So I talked with some Transmission guys who told me about the metal gear that is pressed on, so I got one of these. No problems now! Good Luck! ...Mark

u no wut the funy thing is..i'm positive the gears in there firmly.. i stuck my finger in there.. felt it was there.. ten tried to move it side to side to see if it was loose... but nope.. this is really wierd.. might have to bring it to the shop.. i got the day off today so im gona climb under there again for the 5th time and play around.. maybne jack the rear end up put it in gear and see if the gear actually turns?? i don't no.. thanx for the replys

k i figured it out.. that little gear box is scrap.. the very tiny shaft that goes into the trany gear.. it was striped.. just barly.. but if look close enough u could tell.. so i tried to micky mouse it.. still not workin properly.. so i took it out and ran the cable directly into the trany.. so my speedo's gona be way off.. but its better then havin nothin.. till i get a new mini gear box.

Look for the ratio stamped on the old adapter & be sure you get a new one with the same ratio.