How many teeth on the drive gear?

[NEEDA5.0]

Anyone know how many teeth are on the drive gear of a 94 auto w/2.73s?

 

[94Blue302GT]

I'm pretty sure my manual with 2.73's had an 8 and an 18 teeth gears. for 3.73, just change the 8 to a 6.

 

[ChromeYellow94]

I'm pretty sure my manual with 2.73's had an 8 and an 18 teeth gears. for 3.73, just change the 8 to a 6.

yeah the sn95's do have an 8 tooth drive gear which is stupid cuz if you put in the correct driven gear for 3:73's it will chew it up. The only way to change the drive gear is to tear apart the tranny.

There is a good chart at www.ddperformance.com

 

[Black70Fastback]

some of them according to some people have a 7 tooth but it is most likely an 8 tooth.
if the driven was an 18 it was an 8 tooth drive. if it was 16, it is a 7 tooth drive.

 

[NEEDA5.0]

So I need a 27 tooth speedo gear, great...

 

[Black70Fastback]

ha ha mathmatically yes, but i dont think you can get one. youll either have to change the drive or get a speedcal.

dont it suck. b/c ford could have put a different drive that would work with a lot more gears, but oh well.

 

[Black70Fastback]

wait... im not so sure you can change the drive on on automatic that easy. or can you? i never play with the autos.

 

[V-Viper]

Think this is on topic, I have a 94 5-Spd and am about to get 3.73 gears.

How much will my speedo be off? And what/where can I get the part to fix it. Worth the $$ for install and all? Thanks.

 

[94Blue302GT]

Think this is on topic, I have a 94 5-Spd and am about to get 3.73 gears.

How much will my speedo be off? And what/where can I get the part to fix it. Worth the $$ for install and all? Thanks.

it all depends on if you have 2.73 or 3.08 gears in there right now. however, when i went to the ford dealership the other day, they said that they put the same speedo gears in anyways. i guess that would be why it seems my speedo was a little off. Now i have the speedo gears in, but not the actual 3.73's yet, so i'm WAY off. When it reads 30 i'm doin about 40. I also figured out beforehand that in third at 2 grand i'm doin 40 and in fourth at 1500 i'm doin the same.
What i needed to change to was a 6 and 18 tooth speedo gears, but i already had the 18 tooth in the car(that's the easy one to change) You can get your stuff from ddperformance.com. that's where i went. I think it was like 15 bucks per gear, and it gets there pretty quick, although, they are in michigan, and i'm basically northwest indiana border(actually IL)
Hope it helps!

 

[rel3rd]

wait... im not so sure you can change the drive on on automatic that easy. or can you? i never play with the autos.

That's correct. On an automatic, the speedo "drive" gear is actually part of the output shaft and cannot be changed. A SpeedCal only works on a 5 speed, so you are kinda screwed...I think a chip is the only option, and not 100% sure if that even can do it...

 

[rel3rd]

Think this is on topic, I have a 94 5-Spd and am about to get 3.73 gears.

How much will my speedo be off? And what/where can I get the part to fix it. Worth the $$ for install and all? Thanks.

Without replacing the speedometer drive gear inside of the transmission, you can get fairly close with an aftermarket 23 tooth "driven" gear, but they chew up usually...They do still work that way...I don't know how....but they do...The "correct fix" is to change the internal gear to a 6 toothed one. A SpeedCal will get it very close as well...from what I've heard.

 

[White03Mach]

On a 5spd...as mine... you need to pull the tranny and take off the tailshaft housing. The DRIVE gear is on the output shaft--just a little clip if you are familiar with transmissions. To figure what driven gear you need, multiply the DRIVE GEAR TEETH x REAR END GEAR x # of REVS PER MILE(rear tires) and divide that # by 1000. For example, i changed to a 6T drive gear so i went 6x3.73x805(275/40/17)=18015.9 divided by 1000 = 18.0159 driven gear teeth. Hope this helps you guys

 

[94CobraPace]

A trick is to sand down the OD of the 23 tooth speedo gear. I put the gear in a drill and used sand paper to make the OD smaller, then deburr. When I took mine out at 20k miles it was almost all chewed up. At least by sanding down the OD, there is less plastic in the tranny?

 

[94_Teal_GT]

That's correct. On an automatic, the speedo "drive" gear is actually part of the output shaft and cannot be changed. A SpeedCal only works on a 5 speed, so you are kinda screwed...I think a chip is the only option, and not 100% sure if that even can do it...

SpeedCal says that it works on 1994 and up 5spds AND works on automatics from 1994-1998.

 

[Black70Fastback]

yeah i wouldnt know why a speedcal wouldnt work.
ford also would not have built something tahts not tunable. they had to dial it in somehow to the factory specs when they made the car.