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I recently got a new (to me) 1990 f350 with a E4OD. Except the transmission was missing... So i pulled one from my parts truck. The speed sensor was missing from the parts truck. So now i have the donor transmission in the f350 and a new speed sensor, but no speed sensor gear. Im hoping you gentlemen will know what color/tooth count gear i need for a 1990 F350 with a 7.3 diesel, E4OD and 4.10 gears on stock tires. Anyone know what the factory gear would have been?
additional info: the parts truck is an identical twin to my project truck so no worries about having the proper drive gear.
Unless I'm having a brain fade this AM, on a 1990 you don't have a sensor, right? You should have a speedo drive gear on the trans tailshaft mated to a driven gear and the speedo is cable driven. Don't know about a tooth count, you may have to start out with an uneducated guess when buying a gear. I remember the theory has always been that one tooth difference on the driven gear equals a 10% difference in your speedo reading at highway speeds. Maybe you can work from there.
The formula is (# of drive gear teeth) x (axle ratio) x (tire revolutions per mile) / 1000
16 teeth - Wine- C0DZ-17271-A
17 teeth - WHT- C3DZ-17271-C
18 teeth - YEL - C0DD-17271-B
19 teeth - PNK - C0DZ-17271-B
20 teeth - BLK - C1DZ-17271-A
21 teeth - RED - C4OZ-17271-A
Just guessing but I think you will be be in the 18 tooth range.... the # of drive gear teeth in the formula is the tooth count of the Driving element in the Transmission/transfer case etc etc
Wrong, you want to change just the driven gear (the one retained in the cable), actually done quite a few in the past. If you google those part numbers, they're for DRIVEN gears which IS what you want, although he's calling them drive gears, the drive gear is on the tailshaft of the trrans/transfer case. .
Unless I'm having a brain fade this AM, on a 1990 you don't have a sensor, right? You should have a speedo drive gear on the trans tailshaft mated to a driven gear and the speedo is cable driven. Don't know about a tooth count, you may have to start out with an uneducated guess when buying a gear. I remember the theory has always been that one tooth difference on the driven gear equals a 10% difference in your speedo reading at highway speeds. Maybe you can work from there.
She she has a hall effect sensor that the driven gear is attached to, like the Ford explorers of the late 90s and early 2000s. The speedo is indeed cable driven but it also has a hall effect sensor for the transmission shift points.
Wrong, you want to change just the driven gear (the one retained in the cable), actually done quite a few in the past. If you google those part numbers, they're for DRIVEN gears which IS what you want, although he's calling them drive gears, the drive gear is on the tailshaft of the trrans/transfer case. .
Read the post again. I said that the donor transmission has the same drive gear as the original transmission had. ( in terms of tooth count) because the truck is also identical in every way. Axle Gear ratio, transmission model,engine and so-on.
Read the post again. I said that the donor transmission has the same drive gear as the original transmission had. ( in terms of tooth count) because the truck is also identical in every way. Axle Gear ratio, transmission model,engine and so-on.
Right ... that other guy is on my Ignore list so I don't see his posts for a reason...
the Drive gear on the shaft is what you count the teeth from to plug into the first part of the Equation the resulting number you get is how many teeth the driven gear should have... I posted part numbers for Driven gears in the Range that I thought might apply to you (Often called speedometer cable Drive Gear) most of us I think understood what you were asking
EDIT: By the way there is dozens of websites that you can search that have calculators... just plug the numbers in... same thing as the formula I gave you.
Read the post again. I said that the donor transmission has the same drive gear as the original transmission had. ( in terms of tooth count) because the truck is also identical in every way. Axle Gear ratio, transmission model,engine and so-on.
Wasn't referring to your post at all plus I agree with you. Was referring to the post with the correct part numbers for driven gears but calling it a drive gear. Poor parts men have a hard enough time nowadays anyway without guys going in and asking for a part using the wrong name. We had a parts man years ago who had a memory plus mechanical knowledge you would not believe and I remember him saying more than once, "Do you want the part you asked for, or the part you need?"
the Drive gear on the shaft is what you count the teeth from to plug into the first part of the Equation the resulting number you get is how many teeth the driven gear should have...
Not advisable or necessary, you have to tear into the trans or transfer case to see and count the drive gear teeth, just take a guess, buy a gear, check actual highway speed versus speedo reading, then like I stated, one tooth makes a 10% difference in your speedo reading, then figure the gear you need, real simple. Plus IIRC the drive gears on the output shaft are all the same number of teeth, it's the driven gear only, that the cable fits into,that varies in the number of teeth.
