unhappy with new gear, have a ?

[diablostang]

I ordered my red speedo gear for my tranny this past week, so I got it installed today, and test drove it.... I was very dissapointed.. it was even more off than usual....

My question is, I pulled a WHITE gear out, (and after looking it up, it's the gear for thge 4:10's) but it had a lot of broken teeth.. Do you think that I might have 4:10 gears instead of 3.73's.. The guy who sold me the car said they were 3.73's... Any way to figure out what ratio they are?

Thanks

PS: It was roughly 10-12 mph off at 45 mph.... if that helps any.

 

[jrichker]

Jack the rear end up, put it on jackstands. Paint a mark on the driveshaft where you can easily see it when the driveshaft turns. Turn the rear wheel 1 turn, and count the number of turns the driveshaft makes. If you get about 3 1/2 turns on the driveshaft, the gears are 3.55's. If you get about 3 3/4 turns on the driveshaft, the gears are 3.73.

Here's the best fix for the speed problem...

Check to see if there is a speedometer shop in your area. If there is, ask about the Stewart-Warner speedometer gearbox. I believe it is either a 777 Series Drive Joint Kits and Parts or 666 Series Drive Joint Kits and Parts. It is a small gear box that fits between the speedo pickup gear on the transmission and the speedometer. It has quick change gears that allow you to choose almost any tire size and rear end gear ratio you want. This will allow you to get the accuracy with within 2%-3% or less. The drawback is that it isn't cheap.

 

[diablostang]

Thanks for the reply, I'm on a VERY limited budget with this car, so even buying a new speedo gear is not something I want to do, though I'll probably have to

Is there an easier way of figuring out the gear ratio? I don't have any jackstands yet... I could put it on blocks and do it I guess, but I thought I'd check for an easier way first .

 

[manpowermustang]

Do you have a floor jack? If so put it ynder the rear diff and jack it just enough to see the DR.

 

[diablostang]

Unfortunantly not that either, I'm gonna have to borrow a Jack off the F-150, my scissors jack has too short of a handle to use under the diff

 

[diablostang]

I jacked it up and tested it out... I did it twice, and both times came out around 3 and 3 quarter turns... So I apparently have 3.73's like I was told.. But my gear still doesn't fix the problem.

Any suggestions?

 

[willys1]

I ordered my red speedo gear for my tranny this past week, so I got it installed today, and test drove it.... I was very dissapointed.. it was even more off than usual....

My question is, I pulled a WHITE gear out, (and after looking it up, it's the gear for thge 4:10's) but it had a lot of broken teeth.. Do you think that I might have 4:10 gears instead of 3.73's.. The guy who sold me the car said they were 3.73's... Any way to figure out what ratio they are?

Thanks

PS: It was roughly 10-12 mph off at 45 mph.... if that helps any.

I think 89 and newer needed the 23 toothed white gear.But 88 and older had a different sized gear inside the tranny,so its different then the white gear.

 

[diablostang]

I think 89 and newer needed the 23 toothed white gear.But 88 and older had a different sized gear inside the tranny,so its different then the white gear.

90 + had a different gear, but I got the earlier gear for mine.

 

[Funanin]

If u are in 5th gear going 60 mph at almost exactly 2k then u have 3:73's.

I think u need the white gear but not positive cuz u got the 88 which has slightly different ratios than the 90-93. Any way possible the person before u could have had it rebuilt or swapped for a newer one?

 

[diablostang]

If u are in 5th gear going 60 mph at almost exactly 2k then u have 3:73's.

I think u need the white gear but not positive cuz u got the 88 which has slightly different ratios than the 90-93. Any way possible the person before u could have had it rebuilt or swapped for a newer one?

I'd suggest reading the thread before replying

 

[mob]

im not sure how acurate it is, but on 50resto they have the 21 tooth gear, for a 83-89 5speed 3.73 gears, its 8 bucks, you can probably mow a lawn or recycle some cans for that much, it shows it as a red gear, i think thats the one you have, maybe its something else, if your sure you have 3.73's and you have the red gear... try calling a speedo shop maybe they can tell you over the phone or something

 

[diablostang]

im not sure how acurate it is, but on 50resto they have the 21 tooth gear, for a 83-89 5speed 3.73 gears, its 8 bucks, you can probably mow a lawn or recycle some cans for that much, it shows it as a red gear, i think thats the one you have, maybe its something else, if your sure you have 3.73's and you have the red gear... try calling a speedo shop maybe they can tell you over the phone or something

Yeah, I ordered it from 50resto, it was almost $14 including shipping, and I confirmed above, i do have 3.73 gears.. I just ordered a 140 mph speedo off eBay, hopefully this will help matters some <sigh>

 

[joelliott]

Man those 140 speedos are expensive. Unfortuantely with 3.73s to get above the stock 85 mph limit your gonna be pulling some good rpms.... Hope it installs good for ya. Isnt there another gear in the tranny that can effect speedo output?
Joe E.

 

[Darkhorse845]

Try 50Resto

 

[PNY PWR]

Don't just go off what year your car is. Mine is supposed to have the 8 tooth drive gear in the tranny but it doesn't, it has a 7 tooth. Luckily I checked before I just ordered a speedo gear. You need to check and see what the drive gear is in the tail housing, make sure of your 3.73's, and calculate it all with your tire size included.

Here's a couple of links that will get you the correct gear or gear combo you need.
http://www.geocities.com/mgnedell/notchback/tech/speedo.html

http://www.hanlonmotorsports.com/t5speedo.asp

 

[diablostang]

Try 50Resto

It's unbelievable how many people don't read the thread, then reply the exact same thing several other people said..

 

[diablostang]

Don't just go off what year your car is. Mine is supposed to have the 8 tooth drive gear in the tranny but it doesn't, it has a 7 tooth. Luckily I checked before I just ordered a speedo gear. You need to check and see what the drive gear is in the tail housing, make sure of your 3.73's, and calculate it all with your tire size included.

Here's a couple of links that will get you the correct gear or gear combo you need.
http://www.geocities.com/mgnedell/notchback/tech/speedo.html

http://www.hanlonmotorsports.com/t5speedo.asp

Thanks for the link, according to the page, the gear I have in now IS correct, so I'm at loss as to what to do now..

I didn't count the teeth on the gear I pulled out, after looking at it, it had a lot of broken teeth, so I just tosssed it.

 

[wht93gtEd]

how can you tell what your drive gear in the tranny is?? according to my axle identification tag, I have a 3.27 limited slip rear. So I went to the Ford dealer & picked up a gear for that. It's a 90 tranny, so the guy gave me a red gear (which is correct according to the chart) but i'm still off by 5mph at all speeds. I'm thinking that maybe the drive gear is different than what it should be, so is there any way I can tell which drive gear I have?? thanks.

 

[PNY PWR]

Thanks for the link, according to the page, the gear I have in now IS correct, so I'm at loss as to what to do now.


I didn't count the teeth on the gear I pulled out, after looking at it, it had a lot of broken teeth, so I just tosssed it.

Is your 88 a 5spd or AOD?

Not the gear you pulled out, the drive gear that's inside the tranny. You need to know what is in there to match up a speedo gear. From what you're saying, it sounds like you might have an 8 tooth drive gear.

The drive gears are color coded like the speedo gears. Use a mirror and flash light or whatever to look through the hole where you removed the speedo cable. All you need to do is see what color that drive gear is inside the tranny.
E3ZZ-17285-B
6 Tooth Internal Drive Gear / Black
E3ZZ-17285-A
7 Tooth Internal Drive Gear / Yellow
F0ZZ-17285-A
8 Tooth Internal Drive Gear / Green

Mine's a T5, I'm running 3.73 gears, yellow 7 tooth drive gear, red 21 tooth speedo gear, and stock 225/60/15's. My speedo is absolutely perfect according to mile markers. I can run 5 mile markers and it's still clicking over right at the next one.

 

[PNY PWR]

how can you tell what your drive gear in the tranny is?? according to my axle identification tag, I have a 3.27 limited slip rear. So I went to the Ford dealer & picked up a gear for that. It's a 90 tranny, so the guy gave me a red gear (which is correct according to the chart) but i'm still off by 5mph at all speeds. I'm thinking that maybe the drive gear is different than what it should be, so is there any way I can tell which drive gear I have?? thanks.

Try the mirror and flash light trick I posted above. It's possible you have a 7t drive gear and need a pink 19t speedo gear.